Exam-Oriented Anatomy: Questions and Answers, Vol 1 [2 ed.] 9789354660665

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Volume 1

Exam-Oriented

naom

Questions and Answers Second Edition □ General Anatomy □ Lower Limb

□ General Histology □ Upper Limb

Shoukat N Kazi

MS (Anatomy), DTCD, BSc, LLB

Principal, Dr Tasgaonkar Medical College and Research Centre, Karjat, Maharashtra Ex-Principal, Prasad Institute of Medical Sciences Banthara, Lucknow (UP) Ex-Professor Rajshree Medical Research Institute, Bareilly SRM Medical College Hospital and Research Centre, Potheri, Chennai Chennai Medical College Hospital and Research Centre, Trichy Dr DY Patil Medical College, Pimpri, Maharashtra Dr DY Patil Vidyapeeth (Deemed to be University), Pimpri, Pune

CBS

CBS Publishers & Distributors

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Disclaimer Science and technology are constantly changing fields. New research and experience broaden the scope of information and knowledge. The authors have tried their best in giving information available to them while preparing the material for this book. Although, all efforts have been made to ensure optimum accuracy of the material, yet it is quite possible some errors might have been left uncorrected. The publisher, the printer and the authors will not be held responsible for any inadvertent errors, omissions or inaccuracies. eISBN: 978-93-546-6066-5 Copyright © Authors and Publisher Second eBook Edition: 2021 All rights reserved. No part of this eBook may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system without permission, in writing, from the authors and the publisher. Published by Satish Kumar Jain and produced by Varun Jain for CBS Publishers & Distributors Pvt. Ltd. Corporate Office: 204 FIE, Industrial Area, Patparganj, New Delhi-110092 Ph: +91-11-49344934; Fax: +91-11-49344935; Website: www.cbspd.com; www.eduport-global.com; E-mail: [email protected]; [email protected] Head Office: CBS PLAZA, 4819/XI Prahlad Street, 24 Ansari Road, Daryaganj, New Delhi-110002, India. Ph: +91-11-23289259, 23266861, 23266867; Fax: 011-23243014; Website: www.cbspd.com; E-mail: [email protected]; [email protected].

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Representatives Hyderabad Pune Nagpur Manipal Vijayawada Patna

To My parents Late Haji Nizamsaheb K Kazi

Late Hajjan Mrs Jainnabbi N Kazi My wife Kamartaj For tolerating my preoccupation And my daughter Sadiya For understanding me And Students For appreciating my way of teaching and providing me a continuous stimulus to write the book

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Foreword to the Second Edition

P

rof SN Kazi's Exam-Oriented Anatomy, 2nd edition, is going to compete with all other books on the subject available in the market. It is not only simple, digestible and very attractive but also exceptionally informative and rich into the extent that even heavy textbooks do not carry so much information. I have great respect for him, for his dedication and lust for writing book. I wish him all the best. Dr Nafis Ahmad Faruqi Professor Department of Anatomy Jawaharlal Nehru Medical College Aligarh Muslim University, Aligarh, UP India

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Foreword to the First Edition

P

rof SN Kazi's book is intended to help medical students rapidly master complex intricacies of human anatomy that is essential to clinical care. This book was written to fulfill the need for a brief, but readable, summary of the relevant anatomy, with succinct notes on applied anatomy wherever indicated. It addresses the diverse and mounting need of medical students preparing for professional examinations. The text will not only enhance the knowledge to an extent sufficient to satisfy the examiners but will also equip the readers with the necessary understanding of applied anatomy for future practice. A recurring problem in medical education is the common inability of the students to relate the large body of factual knowledge to practical application in their future clinical training. A commendable endeavour has been made by Prof Kazi to bridge the gap between rote anatomy and clinical relevance. The mnemonics and humour in this book do not intend any disrespect for anyone, rather they are employed as an educational device, as it is well known that the best memory techniques involve the use of ridiculous association. Stephen Goldberg in his unique book titled "Clinical Neuroanatomy Made Ridiculous Simple" has already demonstrated their efficacy superbly. Books Above diaphragm Below diaphragm

LAQs

SAQs

SNs

93

20

156

47

38

125

Keywords Line diagrams Tables

91

49

254 254

47 47

This book is not designed to replace standard reference textbooks, but rather is to be read as a companion text before appearing in an examination. This will enable the student to gain an overall perspective of essential anatomy. My best wishes for the success of this endeavour which merits appreciation. Prof (Dr) Mahdi Hasan

MBBS, MS (Hons.), FICS, FAMS, PhD,DSc, FNA

Professor Emeritus INSA Senior Scientist, Department of Anatomy Chhatrapati Shahuji Maharaj Medical University (King George's Medical University) Lucknow, UP (India) Formerly

Professor and Chairman, Department of Anatomy and Founder Director Interdisciplinary Brain Research Center Dean, Principal and Chief Medical Superintendent Jawaharlal Nehru Medical College, Aligarh Muslim University, Aligarh, UP (India)

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Foreword to the First Edition

A

ll the medical colleges in the state of Maharashtra were affiliated to eight different conventional universities in the state up to 1997. After the establishment of Maharashtra University of Health Sciences in the state in 1998, all of them were affiliated to this single state level university. Previously syllabi and pattern of examination were different but the new pattern (1 + 1½ + 2 years) of curriculum recommended by the Medical Council of India while the conventional universities were following the old (1½ + 1½ + 1½ years) pattern. First time in the examination, LAQ, SAQ and MCQ patterns were introduced by MUHS. On the background of the reduced duration for both students (for learning) and teachers (for teaching) of I MBBS, there was a need for examination­ oriented revision book. It is really a great pleasure for me to introduce this book on human anatomy written by one of my ex-colleagues, Dr SN Kazi. I have gone through the manuscript of this book which adequately covers the subject. Usually students have to purchase separate books for anatomy, histology, embryology, general anatomy, genetics, etc. Dr. Kazi has tried to cover all these branches in simple language with the help of computerized line diagrams. It is designed to meet the need of the undergraduate exam going students. Most of the information are given in tabular forms, easy to compare and remember and clinical applications of the subject have been touched adequately. The book speaks the long experience of the author in the subject and will minimize the stress and strain of a medical student during pre-examination period. I congratulate the author for this venture and wish the book great success.

Shingare PH Professor and Head, MS Department of Anatomy Grant Medical College and Sir J J Group of Hospitals Byculla, Mumbai Director of Medical Education and Research, Maharashtra Ex-Dean, Faculty of Medicine, North Maharashtra University Ex-Controller of Exam, MUHS, Nashik Ex-Chairman, BoS Preclinical, MUHS, Nashik Member of BoS Preclinical Faculty of Medicine and Faculty of Dentistry, MUHS Ex-Vice Dean UG, Grant Medical College, Mumbai Ex-Vice Dean PG, Grant Medical College, Mumbai

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Preface to the Second Edition

I

am very much excited to present the 2nd edition. Initially I thought it will not take much time, but as I started preparing for the 2nd edition, new ideas start clouding in my mind and the ideas went on increasing. In the last 15 years, I received many feedbacks about inadequate answers, too much simplicity of the text, too many mnemonics. I reviewed various books on memory techniques and came with various ideas. I am happy to share the experiences of teaching in different parts of country. In north and central part of India, the main barrier is writing skills. The students are either from Hindi medium or language of regional medium. The immediate challenges after joining medical course is communication and managing vast syllabus. I have made an attempt to write in very simple language. In the first reading only, the student should be able to understand the contents. I have used the symbols for most of the words. It is rightly said "A picture is equal to thousands of sentences. A cartoon is worth of thousands of pictures". Visual memory works better for the pictures than the texts. Colours have deep impact than black and white. Kinesthetics have far more effect as compared to auditory and visual. Combined effects of auditory, visual and kinesthetic have profound effect on memory. A sincere attempt is made not only to give the contents of the subject, but also to make the student remember the subject by using various techniques. The author has attended the lectures of the many anatomists, studied the delivery of lectures. He has picked up the concepts and presented in the form of book. The book is collections of techniques used by well-known anatomists of India. Memory Technique 1. Association memory A. Day-to-day examples: City bus for ascending and descending tracts. B. Association of letters a. After "C" to recollect the nuclei of cerebellum. b. ABCD for the normal constrictions of oesophagus c. Ruffini for red and Krause for cold receptor. This was contributed by Dr Nandedkar madam, a senior anatomist from AFMC. C. Association of digit 10 for 4 important information of oesophagus. a. Length of oesophagus b. Constrictions of oesophagus c. Opening in diaphragm at 10th thoracic vertebra d. First mark on the paediatric Ryles tube. 2. Use of one's hand for representation of various structures and relations A. Branches of splenic artery B. Intermuscular spaces C. Use of 3 fingers for transpyloric plane at lower 1st lumbar D. Branches of basilar artery E. Tributaries of coronary sinus 3. Framing the rules for registration of information A. Rule of alternate framed by honorable late Padmashree Dr Mahdi Hasan to a. Recollect the

viii

Exam-Oriented Anatomy

I. Paired and unpaired branches of abdominal aorta IL Peritoneal and retroperitoneal structures. b. Dropping the alternate letters to recollect the names of extrapyramidal tracts. B. Use of jiggle "Carotico parotico Tonsilii Tympani" to complete the distribution of glossopharyngeal nerve. This is contributed by famous anatomist and surgeon Dr Kadasne, author of many textbooks. C. Use of fingers to differentiate to walls of artery and vein. This is contributed by Dr Krishna Garg madam, editor of world famous textbook BD Chaurasia's Human Anatomy. 4. Link technique 5. Meaning of words A. Dura-hard, durable B. Dia-in between 6. Peg technique Mnemonic-Laila Loves Majnu for the branches of lateral cord of brachial plexus. 7. Simile: Course of hepatic artery represented by badly driven nail. Referred from Surgical Synopsis. 8. Picture mnemonic to represent Cri du chat syndrome. 9. Stories A. A girl from South and boy from Chandigarh had friendship in Jaipur. They got married in Jaipur but marriage could not survive because of different culture and food habit. They got divorced. Boy went back to Chandigarh and got married in own community. This story is appealing for origin, course and distribution of accessory nerve. The story was fabricated by Dr Aruna Mukherjee, a well-known anatomist. B. A story of water pipe for the course of internal pudendal artery. 10. Text in simple English. 11. Things added with religious sentiments: Dr Mysorekaraneminent, Professor of AFMC, used to teach functions of thalamus by giving simile of thalamus to God Nandi and cerebrum with Lord Mahadev. 12. The concept of mind mapping, introduced by Tony Buzan, is used to depict the branches of brachial plexus. 13. Use of celebrities A. Mary Korn-action of serratus anterior B. Ajay Devgn for overriding of horse to make understand the features of Fallot's tetralogy. 14. Use of key advertisements as the keywords-PROV for features of Fallot's tetralogy. 15. Use of airplane and navies for reminding suprascapular artery and nerve, above and below the suprascapular ligament. 16. Use of pictures of anatomy students whose passion is body building. A photo of Wasim Khan is used to display the actions of sternal and clavicular head of pectoralis major. 17. Fruit of pine tree to show pineal body. 18. Use of symbols and pictures of muscles to boost the memory. It was a feedback from the passed-out students that there is mismatch between what is taught in applied anatomy in the first year and what is expected in clinical posting. To fill up the gap, the author has reviewed the applied anatomy from physician, general surgeon, ENT surgeon, ophthalmologist, orthopaedic surgeon, and geneticist. The author has reviewed various regions from senior anatomists. All the feedback has been meticulously rectified. Separate boxes are introduced for the understanding of the subject and for memorization. Shoukat N Kazi

I

Acknowledgements to the Second Edition

I

recollect the days, when I determined to write for the second edition. I thought of getting all the books of anatomy that are freely available and accessible. I collected books from all the old book bazar in Delhi, Mumbai, Pune, Pimpri, Lucknow, Ahmedabad, Rajkot. I am very much thankful to Dr TC Singel, Professor, Department of Anatomy, Zydus Medical College, who took me to various old bookstores in Ahmedabad and made them available. He also lent me the library books. It was a great help. I could get the books which are not available in any of the college library. I am very much grateful to him. I cannot afford to forget the continuous encouragement given by Mr Bhagwan Yadav, Chairman, Managing Director, Prasad Institute of Medical Sciences, Lucknow. Scanning of the book was done by our office staff, namely Prajakta, Rhutuja. I am thankful to them. I need to mention the name of Mr Rehan Ansari, (HR, Prasad Institute of Medical Sciences, Lucknow) who got the books scanned in a very short time. There were vital technical issues, because of which I was handicapped. The problems were resolved by my nephew, Mr Wahab Kabir Kazi. I am very much thankful to him. The basic suggestions of diagrams were made by a corel artist Mr Sanjay, CBS Publishers & Distributors. I am thankful to him. I am really lucky to have the contributions from many professors. To start with, Mrs Jasmine Naik drew some of the diagrams in corel draw but because of her child's health she could not continue. The work was continued by Mrs Zeenat Shaikh. She really put her heart in diagrams. She learnt all the intricacies of anatomy subject and gave her 100% to make the diagrams right. She is very much concerned for the success of the book. The repeated editing of the text and layout of diagrams, sequencing of questions, was done untiringly by Miss Parveen Shaikh and Mrs Jyoti Dhage. In addition to editing, Miss Parveen Shaikh has kept an eye on all the activities and coordinated in a very efficient way. They are the backbones of the book, without their help, the quality of the book was not possible. I am really blessed to have the staff, namely Miss Parveen Shaikh, Mrs. Jyoti Dhage and Mrs Zeenat Shaikh. Mrs Maya Bhujbal, and Mr Uday Jadiye, who have helped in minute layout of the book. I am indebted for the help my brother Mr Kabir Kazi has extended to me. He has helped me in organizing guest lectures, workshops and made me tension free to write the book. It was a continuous support to me. The continuous inspiration and motivation was given by my brothers Mr Shikandar, Allabaksh and Najir Kazi. The technical support was given by Mr YN Arjuna Senior Vice-President-Publishing, Editorial and Publicity, and his team. He has understood me and helped without any hesitation.

X

I

Exam-Oriented Anatomy

The real financial help was extended by Mr Satish Kumar Jain, CMD, CBS Publishers & Distributors. His help was stress bursting to me. The quality of the book has reached only because of his timely help, and the patience he has shown to me. We have very good bonding for so many years. I am really thankful from the bottom of my heart to Mr Varun Jain, Director, who is dynamic in implementing various technology in the books. The animation of neuroanatomy and upper limb and abdomen is being introduced, only because of his initiation. I owe him a lot. The real tolerance and patience were given by my better half Mrs Kamartaj and my daughter Miss Sadiya. I did not give any time and attention to family activities. I appreciate their understanding.

Special Thanks---------------------------

1 am extending my sincere and special thanks to the following persons, without whom the book would not have been completed. • Dr PH Shingare, Professor and Head, Department of Anatomy, Grant Medical College, Mumbai, has meticulously corrected the text and has given solutions to diagrams. He has tolerated my disturbance at odd hours in his busy schedule. • Dr (Mrs) Kanaklata Iyer, Professor of Anatomy at Somaiya Medical College, Sion, Mumbai, has really given a breakthrough to the problems of diagrams. She has helped out rightly by sparing her valuable time through her busy schedule by taking keen interest. She has contributed diagrams of gross anatomy of abdomen, inferior extremity and general embryology. • Dr Savgaonkar, Professor of Anatomy at BJ Medical College, Pune, has drawn histology diagrams of abdomen section. He being my close friend, understood the difficulties and offered his help by completing the diagrams in very short time. • Dr Anjali Dhamangaonkar, Associate Professor, in Anatomy at GS Medical College, Mumbai, has contributed to the general embryology diagrams. It was very difficult for her to give some time. But her desire to help me has solved the problems. • Dr Manvikar Purushottam Rao, Lecturer in Anatomy at Dr DY Patil Medical College, Pimpri, has drawn some of the diagrams of general histology. He is the main push for animation work. • Dr Kadasne DK, the author of Kadasne's Textbook of Anatomy (Clinically-oriented), has allowed me to use some of the diagrams from his book. • Dr Umarji, Professor and Head, Department of Anatomy, Krishna Institute of Medical Sciences, Karad, has drawn a few diagrams of general anatomy.

Shoukat N Kazi

I

Contributors Arudyuti Chowdhury Ms, oGo Associate Professor, SRM Medical College, He was my roommate at SRM Medical College, Chennai. Dr Arudyuti Chowdhury is constant motivators. He has helped me in all the activities. His word of suggestion is important for me.

Ashok Kumar Rawat

(0rtho) Assistant Professor, Department of Orthopedics, Associate Professor, Prasad Institute of Medical Sciences, Lucknow. He has helped in giving fine touch of applied aspects of joint. MS

Gangane Professor and Head, Department of Anatomy, Medical College, Navi Mumbai. Thank you very much for finding time for approving the contents.

Jyoti Kulkarni Professor in Anatomy in Nepal She has gone meticulously in all the texts and diagrams of books and given valuable suggestions. The quality of the book is definitely improved because of her suggestions. I am very much obliged and thankful for her help.

Manvikar Professor and Head, Department of Anatomy, Padmashree, Dr DY Patil Medical College, Pimpri, Pune. Thanks very much for giving genetic inputs.

MC Srivastav Medical Superintendent and Associate Professor of Medicine, Prasad Institute of Medical Sciences, Lucknow. He is kind enough to add EKG changes in blockage of coronary arteries.

Murugan Kutty Gopalan

BSc, MBBS, DMA (USA)

Head, Departments of Medical Illustrations, Digital Health, Clinical Skills Simulation Center and Telemedicine, Amrita Institute of Medical Sciences and Research Center, Kerala, India. He is involved in the Simulation-Based Medical Education in giving training in various clinical skills. He is intensely working on introducing new generation Medical

Haptics, Robotic Surgery, Cardiac-Neuro-Ortho interventional Simulaids for the super-specialty branches in Medicine and

Surgery. He has won several regional, national and international awards for his innovative illustrative works. All histology diagrams of 2nd edition are fabricated by Dr Gopalan. Apart from contributions to the book, he is my very close friend, whose door I can knock for any help any moment. I am heavenly blessed to have a friend like Dr Gopalan.

He is courageously fighting his health issue like a warrior. I know him since last 15 years. He is very much energetic. The energy and enthusiasm have increased many folds after he met his health issue. I think adverse situations boost his energy. I do not know from where he gets energy to do such activities. I pray God to give him long healthy life.

Nayana Karodpati Professor (ENT, DYPMC), Pimpri, Pune

She edited the text and added the topics which are of clinical importance. Hearty thanks for the help.

P Vatsalaswamy

MD

Director of DYPMC, Pimpri, Pune In spite of her busy administrative activities and family commitments, she could spare time and could help me. I am very much obliged. She has reviewed superior extremity. She has gone in details of each word of text and given the feedback.

Salamat Khan Professor of Surgery, Prasad Institute of Medical Sciences, Lucknow. Dr Salama! Khan has voluntarily helped me in reviewing applied anatomy of limbs, abdomen, head, neck, face, thorax, and brain. He has gone word to word and gave the suggestions. I salute him for his help.

Sunita Nayak Assistant Professor All India Institute of Medical Sciences, Patna

Ubaidur Rehman Medical Superintendent, Prasad Institute of Medical Sciences, Lucknow. He has helped in updating ophthalmology chapters. I was lucky to be associate with him.

Vaishali Bharambe

MD, PhD

Ex-professor, DY Patil Medical College, Pimpri, Pune Presently she is working as a Professor and Head, Symbiosis Medical College, Pune. She was very much busy in preparation of PhD. In spite of her hectic schedule, she could review the diagrams of lower limb. I owe her.

Vinod Kathju Former additional Principal, Dr SN Medical College, Jodhpur I am very much thankful for his kind guidance and contribution

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Upper Limb: Animation

Sr. No.

Duration

Topic

BP1

4.25

Introduction to nerve plexus

BP2

1.23

Objectives of the video

BP3

2.23

Formation of brachia! plexus

BP4

1.23

Fixation of brachia! plexus

BPS

0.50

Anatomy of brachia! plexus

BP6

1.41

Nomenclature of brachia! plexus

BP7

1.13

Branches of brachia! plexus

BP8

2.05

Branches from cords and details of nerve

BP9

1.10

Details of each nerve

BP10

3.41

Nerve to serratus anterior

BP11

1.35

Applied anatomy of nerve to serratus anterior

BP12

2.58

Suprascapular nerve

BP13

1.37

Nerve to subclavius

BP14

1.19

Branches of lateral cord

BP15

7.02

Musculocutaneous nerve

These high-value animation videos are available on CBSiCentral App through scratch code. Please see the front inner cover for obtaining access code.

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Contents

Foreword to the Second Edition by Dr Nafis Ahmad Faruqi Foreword to the First Edition by Prof (Dr) Mahdi Hasan Foreword to the First Edition by Shingare PH Preface to the Second Edition

■�_______

iv V

vi vii

_ _ n_1_Ge_ n_ e_r_ a l_ A_na_t o _ _m_Y_________ s_ ec_ t_io

1. Skeleton SN-1 SAQ-1 SN-2 SN-3 SN-4 SN-5 SN-6 SAQ-2 SN-7 SAQ-3 SAQ-4 SAQ-5

Long bone 3 Short bones 5 Pneumatic bone 7 Sesamoid bone 7 Periosteum 9 Epiphysis 11 Diaphysis 13 Metaphysis 13 Blood supply of the long bone 14 Growing end 17 Primary centre of ossification 18 Secondary centre of ossification 18

■

SN-12 SN-13 SN-14 SN-15 SN-16

Primary cartilaginous joint (synchondrosis) 23 Secondary cartilaginous joint (symphysis) 23 Typical synovial joint 24 Classification of synovial joint 25 Pivot joint 27

3. Muscles OLA-1 SAQ-6 SN-17 SN-18 SN-19 SN-20

19

2. Joints SN-8 SN-9 SN-10 SN-11

3

Classification of joints 19 Fibrous joints 20 Suture 21 Syndesmoses 22

What is a sarcomere? 28 Pinnate muscles 28 Prime movers (agonists) 30 Antagonist 30 Fixators 31 Synergist 31

4. Cardiovascular System OLA-2 SN-21 SN-22 SN-23

28

32

Enumerate 4 arteries commonly used for palpating peripheral pulsations 32 Anastomosis 32 End arteries 33 Bursa 34

Section 2 Ge nera l Hist ology ________ _

.._

5. Epithelium SAQ-1 SN-1 SN-2 SN-3 SN-4 OLA-1 OLA-2 OLA-3 OLA-4 SN-5

6. Connective Tissue SN-6 SN-7 SN-8 OLA-5

37

Simple squamous epithelium 37 Simple columnar epithelium 38 Pseudostratified epithelium 39 Stratified squamous epithelium 39 Transitional epithelium (urothelium) 40 What is brown fat? 41 Draw and label a section of a cilium 41 Classify compound epithelium with examples 42 What are the differences between microvilli, cilia and stereocilia? Explain with the help of diagrams 42 Junctional complexes 43

45

Write a note on dense regular connective tissue 45 Write a note on adipose tissue 46 What are the different types of cells in a connective tissue? What are their identification points and functions? 47 Describe plasma cell 51

7. Cartilage SN-9 SN-10 SN-11 SN-12

52

Draw and write a note on articular cartilage 52 Draw and write a note on hyaline cartilage 54 Draw and write a note on fibrocartilage 55 Draw and write a note on elastic carti I age 57

8. Bone OLA-6 OLA-7 OLA-8

59

What are Howship's lacunae? 59 What is osteon? Or Haversian system? 59 State the different types of lamellae in the bone 59 OLA-9 What is Volkmann's canal? 60 OLA-10 State the cells of bone. Describe each briefly. 60 OLA-11 What is osteoclast? 61 SN-13 Compact bone 61

9. Muscle

64

OLA-12 Classify muscles with examples 64 OLA-13 Describe transverse section (TS) of skeletal muscle 64 OLA-14 Describe longitudinal section (LS) of skeletal muscle 65 OLA-15 What is intercalated disc? What are its functions? 65 OLA-16 Difference between smooth, cardiac and skeletal muscles 66

Exam-Oriented Anatomy

xiv

11. Lymphoid Tissue

OLA-17 Cardiac muscle 66 SN-14 Sarcomere 67

1 o. Blood Vessels

■

SN-15 SN-16 SN-17

Draw and describe muscular artery 69 Draw and describe elastic artery 70 Draw and describe vein 71

69

74

OLA-18 Draw and describe any of the following: Spleen, lymph node, tonsil, thymus 74 SAQ-2 Loose areolar tissue 75

Section 3 Lower Limb

L___________

12. Bones of Lower Limb OLA-1 OLA-2 SN-1 SAQ-1 SN-2 SAQ-2 SN-3 SAQ-3 SAQ-4

79

Attachments to intertrochanteric line 79 Enumerate the structures attached to pubic tubercle 79 Greater sciatic notch 79 Organs related to hip bone 81 Linea aspera 81 Adductor tubercle 83 Iliac crest 83 Structures attached to spines of hip bone 85 Trochanteric anastomosis 85

13. Front of Thigh

87

Name the muscles forming boundaries of femoral triangle 87 OLA-4 Name the muscles forming the floor of femoral triangle 87 OLA-5 Name the structures forming the boundaries of femoral ring 87 OLA-6 Name the cutaneous nerves seen in roof of femoral triangle 87 OLA-7 Name the muscles of anterior compartment of thigh 88 SN-4 Superficial inguinal lymph nodes 88 SN-5 Fascia lata 90 SN-6 lliotibial tract 91 Saphenous opening 91 SN-7 SAQ-5 Name the branches of femoral artery in femoral triangle 93 LAQ-1 Describe femoral triangle (triangle of Scarpa) 94 OLA-8 Name the fascia forming the femoral sheath 101 SAQ-6 Enumerate the contents of femoral sheath 101 SN-8 Femoral sheath 101 SN-9 Femora I cana I 104 LAQ-2 Describe femoral artery 107 OLA-9 What is the root value of femoral nerve? 111 OLA-10 What is the root value of obturator nerve? 111 SAQ-7 Name the branches of femoral nerve 111 LAQ-3 Describe femoral nerve 112 OLA-11 Name the nerves forming the subsartorial plexus 116 OLA-12 Attachments to patella 116 LAQ-4 Describe adductor canal OR Subsartorial canal OR Hunter's canal 117 OLA-3

14. Medial Side of Thigh

120

OLA-13 Enumerate the muscles of adductor compart­ ment 120 OLA-14 Enumerate the muscles supplied by obturator nerve 120 LAQ-5 Describe obturator nerve 120

15. Gluteal Region

124

SN-10 lschial tuberosity 124 OLA-15 Which is the key muscle in gluteal region? 125 OLA-16 Name the nerve supplying gluteal maximus. What is the root value? 125 OLA-17 Name the nerve supplying gluteal medius. What is the root value? 126

OLA-18 Enumerate the actions of gluteus maximus 126 OLA-19 Enumerate the actions of gluteus medius 126 OLA-20 Enumerate the bones under cover of gluteus maximus 126 SAQ-8 Enumerate the muscles under cover of gluteus maximus 126 SAQ-9 Enumer ate the nerves under cover of gluteus maximus 127 OLA-21 Enumerate the vessels under cover of gluteus maximus 127 SN-11 Gluteus maximus 127 LAQ-6 Describe the structures under cover of gluteus maximus 130 SN-12 Gluteus medius 131 SAQ-1 O Cruciate anastomosis 133

16. Popliteal Fossa

135

SAQ-11 Enumerate the muscles forming the boundaries of popliteal fossa 135 SAQ-12 Enumerate the structures forming the floor of popliteal fossa 135 SAQ-13 Contents of popliteal fossa 136 LAQ-7 Describe popliteal fossa 136 SAQ-14 Enumerate the branches of popliteal artery 141 OLA-22 Name the terminal branches of popliteal artery 142 LAQ-8 Describe popliteal artery 142 OLA-23 Root value of tibial nerve 146 OLA-24 Enumerate the terminal branches of tibial nerve 126 OLA-25 Enumerate the branches of tibial nerve in popliteal fossa 146 LAQ-9 Describe the tibial nerve 146 OLA-26 Root value of common peroneal nerve 149 OLA-27 Branches of common peroneal nerve in the fossa 149 SN-13 Common peroneal nerve 150 SN-14 Foot drop 151 SN-15 Popliteus 151

17. Back of Thigh

154

18. Front, Lateral and Medial Sides of Leg and Dorsum of Foot

161

SAQ-15 Name the branches of profunda femoris artery 154 OLA-28 Enumerate the hamstring muscles 155 SN-16 Hamstring muscles 155 OLA-29 What is the root value of sciatic nerve? 156 LAQ-10 Describe the sciatic nerve 156 OLA-30 Name the muscles of posterior compartment of thigh 160

OLA-31 Name the muscles supplied by superficial peroneal nerve 161 OLA-32 Enumerate muscles of anterior compartment of leg 161 OLA-33 Enumerate muscles of lateral compartment of leg 161 OLA-34 Enumerate muscles of posterior superficial compartment of leg 161

xv

Contents OLA-35 Enumerate muscles of posterior deep compartment of leg 161 OLA-36 Name the muscles supplied by deep peroneal nerve 162 OLA-37 Name the branches of dorsalis pedis artery 162 SN-17 Peroneus longus muscle 162 SN-18 Dorsalis pedis artery 163 OLA-38 Cutaneous nerve supply of dorsum of foot. 164

19. Back of Leg

166

SAQ-16 Tibialis posterior muscle 166 OLA-39 Give the attachments and actions of soleus 167 SN-19 Soleus 168

20. Sole of Foot OLA-40 OLA-41 OLA-42 OLA-43 SN-20 OLA-44 OLA-45 SAQ-17 SAQ-18 SN-21 SN-22 SN-23 OLA-46

170

Name the muscles of 1st layer of sole 170 Name the muscles of 2nd layer of sole 170 Name the muscles of 3rd layer of sole 170 Mention the structures in the 4th layer of sole of foot 170 Muscles supplied by lateral plantar nerve 171 Muscles supplied by medial plantar nerve 172 Nerve supply of lumbricals of sole 172 Actions of dorsal interossei of foot 172 Actions of plantar interossei of foot 173 Plantar aponeurosis 173 Comparison between the plantar and palmar aponeurosis 175 Layers of sole 175 Cutaneous nerve supply of sole of foot 177

21. Venous and Lymphatic Drainage and Comparison of Lower and Upper Limbs

179

SAQ-19 Venous perforators of lower limb 179 LAQ-11 Describe great saphenous vein 180 LAQ-12 Describe venous drainage of lower limb 183

22. Joints of Lower Limb

■

185

OLA-47 Which muscles are chief flexors of hip joint? 185 OLA-48 What is the nerve supply of hip joint? 185 OLA-49 Names the articulating surface participating in formation of hip joint 185 OLA-SO Dislocation of hip joint 185 OLA-51 Attachments of capsule of hip joint 186 LAQ-13 Describe hip joint 186 SN-24 Classify knee joint (genual) 190

SN-25 SN-26 SAQ-20 SN-27 SN-28 SN-29 SAQ-21 SAQ-22 OLA-52 SAQ-23 OLA-53 OLA-54 OLA-55 SN-30 SN-31 SN-32 SAQ-24 SN-33 SN-34 LAQ-14 SN-35 OLA-56 SAQ-25 LAQ-15 LAQ-16 SN-36 SN-37

Capsule of knee joint 191 Draw and label the diagram showing anastomosis around knee joint 191 Enumerate intra-articular structures of knee joint 192 Cruciate ligament 193 Compare anterior and posterior cruciate ligaments 194 Meniscus 195 Meniscofemoral ligaments 196 Oblique popliteal ligament 197 Transverse ligament (transverse meniscal ligament) 197 Synovial membrane of knee joint 197 Coronary ligament 198 Arcuate ligament 198 Ligamentum patellae 198 Collateral ligaments 199 Relations of knee joint 199 Movements of knee joint and muscles bringing the movements of knee joint 200 Stability of knee joint 202 Bursae around knee joint 202 Locking and unlocking of knee joint 203 Describe ankle joint (talocrural) 204 Deltoid ligament 207 Movements of ankle joint 208 Lateral ligament of ankle joint 208 Describe inversion 209 Describe eversion 210 Compare pronation, supination with inversion and eversion 211 Spring ligament (plantar calcaneonavicular ligament) 211

23. Arches of Foot SAQ-26 OLA-57 OLA-58 OLA-59 SAQ-27 LAQ-17 LAQ-18

213

Applied anatomy of arches of foot 213 Enumerate functions of the foot. 213 Name the inverters of foot 213 Talipes equinovarus-----clubfoot 214 Supports of arches 214 Describe medial longitudinal arch 214 Describe lateral longitudinal arch 217

Section 4 Upper Limb ----------

24. Bones of Upper Limb OLA-1 OLA-2 SN-1

25. Pectoral Region LAQ-1 SN-2 SN-3 SN-4 SN-5 SN-6 SN-7 SN-8 SN-9 SN-10 SN-11

221

Enumerate the muscles in the upper limb having more than 1 head 221 Enumerate the peculiarities of clavicle 223 Coracoid process 223

225

Describe mammary gland 225 Development of mammary gland 231 Lymphatic drainage of mammary gland 232 Serratus anterior muscle 234 Nerve to serratus anterior 235 Suprascapular nerve 237 Nerve to the subclavius 238 Trapezius 238 Pectoralis minor 239 Pectoralis major 240 Clavipectoral fascia 243

26. Axilla OLA-3

LAQ-2 SN-12 OLA-4 SN-13 LAQ-3 OLA-5 SN-14 LAQ-4 SN-15 OLA-6 OLA-7 SN-16 OLA-8 OLA-9

247

Enumerate the muscles acting in raising the arm above the head 247 Describe axilla 247 Axillary fascial 'tent' 250 Name the branches that arise from each of three parts of axillary artery 250 2nd part of axillary artery 251 Describe axillary artery 253 Axillary lymph nodes 256 Axillary lymph nodes 256 Describe brachia! plexus 257 How does nerve plexus is formed? 260 What is brachia! plexus? 261 What is prefixed and post-fixed brachia! plexus? 261 What are the components of brachia! plexus? 262 What are parts of brachia! plexus? 263 Nomenclature of brachia! plexus 263

Exam-Oriented Anatomy

xvi

OLA-10 Branches of roots, and trunks of brachia! plexus 263 OLA-11 Branches of cords of brachia! plexus 264 OLA-12 Dorsal scapular nerve 265 OLA-13 Branches of lateral cord of brachia! plexus 265 SN-17 Homer's syndrome 266 SN-18 Erb's paralysis 267 SN-19 Klumpke's paralysis 269 OLA-14 Cervical rib 271 OLA-15 Sprengel's deformity 271 OLA-16 Nerve injuries of upper limb 271

27. Scapular Region

SN-32 Extensor retinaculum 324 OLA-35 Name the muscles supplied by median nerve in hand 325 LAQ-12 Describe median nerve 325 OLA-36 Name the superficial flexors of forearm and their nerve supply 331 OLA-37 Branches of ulnar nerve in forearm 322 OLA-38 Name the muscles inserted in the extensor expansion of index finger 322 OLA-39 Enumerate the muscles pass through the carpal tunnel 332 SN-33 Carpal tunnel 333 OLA-40 Cutaneous supply of palm of hand 334 OLA-41 Cutaneous supply of dorsum of hand 335 SN-34 Palmar aponeurosis 335 SN-35 Dupuytren's contracture 335 SN-36 Dorsal digital expansion 336 OLA-42 Enumerate the muscles inserted in the extensor expansion of middle finger 337 LAQ-13 Describe interossei 338 OLA-43 Nerve supply of lumbricals 339 OLA-44 Actions of lumbricals 339 SN-37 Lumbricals 340 OLA-45 Branches of superficial palmar arch 341 LAQ-14 Describe superficial palmar arch 341 OLA-46 Branches of deep palmar arch 342 LAQ-15 Describe deep palmar arch 342 OLA-47 Name the muscles supplied by ulnar nerve in hand 344 LAQ-16 Describe ulnar nerve 344 SN-38 Pulp space 347 OLA-48 Contents of thenar space 347 OLA-49 Muscles of thenar space 348 OLA-SO Nerve supply of muscles of thenar space 348 SN-39 Palmar spaces 349 OLA-51 Extensor expansion of little finger 350 OLA-52 Extensor expansion of ring finger 350 SN-40 Posterior interosseous nerve 350

273

OLA-17 Actions of deltoid muscle and its nerve supply 273 SN-20 Deltoid 273 SAQ-1 Rotator cuff 275 SAQ-2 Quadrangular space 277 SAQ-3 Upper triangular space 278 SAQ-4 Lower triangular space 278 OLA-18 Name the muscles supplied by axillary nerve 279 OLA-19 A ten-year-old girl fractures her humerus at the surgical neck. What damage would you check for and how? 279 LAQ-5 Describe axillary nerve 279 SN-21 Movements of the pectoral girdle 282 SN-22 Winging of scapula 283 SN-23 Ape thumb deformity 285 SN-24 Scapular anastomosis 286

28. Cutaneous Nerves, Superficial Veins and Lymphatic Drainage 287 OLA-20 Describe the origin and termination of cephalic vein 287 LAQ-6 Describe cephalic vein 287 OLA-21 Median cubital vein-importance 290 SN-25 Median cubital vein 291 SN-26 Bicipital aponeurosis 291

29. Arm OLA-22 LAQ-7 OLA-23 OLA-24 LAQ-8 OLA-25 OLA-26 OLA-27 LAQ-9 SN-27 SN-28 SN-29 OLA-28 OLA-29 OLA-30 OLA-31 LAQ-10

31. Joints of Upper Limb

293 Attachments and actions of biceps brachii 293 Describe musculocutaneous nerve 293 Medial pectoral nerve 296 Medial cutaneous nerve of forearm 297 Describe brachia! artery 297 Branches of radial nerve in radial groove 301 Branches of radial nerve in axilla 301 Branches of radial nerve in front of lower part of arm 301 Describe radial nerve 301 Applied anatomy of radial nerve 308 Wrist drop 309 Profunda brachii artery 310 What structures pass between medial and lateral head of triceps? 311 Boundaries of cubital Iossa 312 Contents of cubital Iossa 312 Applied anatomy of cubital Iossa 313 Describe cubital Iossa 313

30. Forearm and Hand

316

OLA-32 Branches of radial artery in forearm 316 LAQ-11 Describe ulnar artery 316 OLA-33 Name the boundaries and contents of anatomical snuffbox 320 SN-30 Anatomical snuffbox 321 OLA-34 What are the attachments of flexor retina­ culum? 322 SN-31 Flexor retinaculum 323

352

OLA-53 Name the factors stabilizing shoulder joint 352 OLA-54 Name the muscles causing adduction at shou Ider joint 352 OLA-55 Muscles causing lateral rotation at shoulder joint 352 OLA-56 Muscles causing medial rotation at shoulder joint 352 LAQ-17 Describe intrinsic muscles of hand 353 SN-41 Branches of ulnar nerve in hand 353 SN-42 Coracoacromial arch 355 LAQ-18 Describe shoulder joint or glenohumeral joint 356 OLA-57 Name the flexors of the elbow joint 360 SN-43 Anastomosis around the elbow joint 360 LAQ-19 Describe elbow joint 361 SAQ-5 Carrying angle 364 OLA-58 Name the movements at radioulnar joints and muscles causing them. 364 SN-44 Radioulnar joints 364 SN-45 lnterosseous membrane 366 LAQ-20 Describe supination and pronation 367 OLA-59 Classify the radioulnar joints 369 OLA-60 Bones forming wrist joint 369 LAQ-21 Describe wrist joint (radiocarpal) 369 OLA-61 Name the movements at metacarpophalangeal joint of middle finger and muscles causing them 374 SN-46 First carpometacarpal joint 374 SN-47 Tennis elbow 376 SN-48 Compare upper limb with lower limb 377 Index

381

1 General Anatomy

• Skeleton • Joints • Muscles • Cardiovascular System

Attention Please All the texts in boxes are not to be written in the examination.

Skeleton

SN-1

1

Long Bone

1. Features of long bone A. It is placed vertically in the body or in the long axis of the body. B. Its length is more than breadth. C. It has a. Shaft with two expanded ends, b. Three surfaces and three borders (Fig. 1.1), c. One diaphysis and more than two epiphyses, and d. Medullary cavity.

Fig. 1.1: Transverse section (TS) of long bone showing three borders and three surfaces

D. It a. Serves as a lever for muscular actions. b. Transmits weight, from axial to appendicular skeleton. c. Develops in cartilage. d. Forms joints with upper and lower ends and with interosseous border. E. Surfaces of long bones are covered by periosteum except articular surfaces. 3

Exam-Oriented Anatomy

4

General Anatomy

1

2. Sub-classification A. Typical long bone: It has all the features of long bone. a. Examples of typical long bones I. Humerus (Fig. 1.2), II. Radius, III. Ulna, IV. Femur (Fig. 1.3), V. Tibia, and VI. Fibula.

Fig. 1.2: Right humerus

Fig.1.3: Long bone—right femur, anterior view

B. Modified long bone: Some of the characters of typical long bones are modified. a. It does not have medullary cavity. b. It ossifies in membrane or cartilage or both. c. The clavicle transmits the weight from appendicular skeleton to axial skeleton. The body of vertebra transmits the weight from axial to appendicular skeleton. Example I. Clavicle (Fig. 1.4) II. Body of vertebra (Fig. 1.5).

Fig. 1.4: Modified long bone—clavicle

Fig. 1.5: Body of vertebra

C. Miniature long bone (Fig. 1.6) (mockery of long bone): It is smaller in all dimensions, namely length, breadth, weight and diameter and has only 1 epiphysis, e.g. a. Metacarpals, b. Metatarsals, and c. Phalanges.

Skeleton

5

Fig. 1.6: Miniature long bones—metacarpals and phalanges

SAQ-1

Short Bones

Introduction: The bones which are not long called short bones (Fig. 1.7). They are cubical

in shape and present six surfaces.

1. Features: Out of six surfaces A. Four are articular, and B. Two are non-articular. 2. Articular surfaces give attachment to muscles and ligaments. 3. They are pierced by blood vessels. 4. Examples A. Carpal bones:

She looks too pretty, try to catch her

Fig. 1.7: Short bones of right wrist

Scaphoid Lunate Triquetral

, , ,

General Anatomy

1

Exam-Oriented Anatomy

6

Pisiform

Trapezium

General Anatomy

1

Trapezoid

Capitate

and

Hamate

.

B. Tarsal bones a. Calcaneus,

b. Cuboid , c. Navicular

and

d. Cuneiform I. Medial cuneiform II. Intermediate cuneiform III. Lateral cuneiform C. Sesamoid

bones

5. Ossification A. They ossify in cartilage. B. They ossify after birth except talus, calcaneus and cuboid which ossify in intrauterine life.

Skeleton

SN-2

7

Pneumatic Bone

(Pneuma air) Introduction: The pneumatic bone has outer and inner tables. It is lined by mucoperiosteum and contains air. 1. Site: Bones lining respiratory passage, e.g. A. Paired: Maxilla a. Frontal, b. Ethmoid, c. Sphenoid. 2. Features: In the pneumatic bone, the spongy substance is replaced by the air-filled paranasal sinuses. 3. Functions:

ARTI

A. It acts as Air conditioning chamber. a. It changes humidity and temperature of the inspired air. b. It makes the air free from foreign particles. B. It acts as Resonance (prolongation and intensification of sound) of the voice. C. It improves Timbre (quality of musical sound) of the voice. D. It provides Insulation. E. They reduce the weight of the bone by 200 to 300 g. 4. Development A. They develop in membrane due to differential growth of 2 tables. B. Inner table breaks up and penetrates into neighbouring mucosa and forms the pneumatic bone. SN-3

Sesamoid Bone

Introduction: It is oval

shaped nodules, a few mm in diameter varying in

shape and size which develops in tendons or/and joint capsule. 1. Nomenclature: Arabic term Sesame—seed-like

, oid—resemblance.

2. Evolution: Phylogenetically it is part of skeleton. 3. Structure: It is formed by fibrous tissue, cartilage or bone which develops in tendon. It exerts a considerable amount of pressure on bony structure (Fig. 1.8). 4. Ossification: It ossifies in 2nd decade except patella which ossifies in the 1st decade.

General Anatomy

1

B. Unpaired

Exam-Oriented Anatomy

8

General Anatomy

1 Fig. 1.8: Right patella showing the attachments of quadriceps femoris

5. Characters: NO

MP HP

A. It does not have: • Medullary cavity, • Primary centre, • Haversian system, and • Periosteum. B. It has articular or non-articular surface. C. The articular surface is covered by hyaline cartilage. D. It is lubricated by bursa or synovial fluid. 6. Functions: The exact function is not definitely known. However, the following functions are attributed. SESAMOID Serves as a mechanical advantage to the tendon. Ensures (makes certain) the prevention of wear and tear of the tendon. Stabilises the local circulation. Alters the direction of pull of the muscle. Maintains the local circulation. Overcomes the pressure. Insures (protects) the vessels and nerves. Diminishes the friction. Site: Following are the sesamoid bones (Table 1.1).

Skeleton

9

Table 1.1: Sesamoid bones related tendons Name of sesamoid bone

• Quadriceps femoris (related to articular surface of knee joint)

• Patella (biggest sesamoid bone)

• Flexor carpi ulnaris

• Pisiform

• Gastrocnemius (lateral head)

• Fabella (little bean)

• Adductor longus

• Riders bone

• Flexor pollicis longus

–

• Flexor pollicis brevis

–

• Adductor pollicis

–

7. Applied anatomy  Failure of ossification is mistaken for fracture of bone, e.g. patella.  Stress fracture occurs in ballet dancers and long-distance runners. SN-4

Periosteum

(Greek. Peri—around, osteon—bone) 1. Definition: The surface of the shaft and part of the ends are covered by periosteum (Fig. 1.9).

Fig. 1.9: Long bone—periosteum

A. Features a. At the ends of the bones, the periosteum blends with the fibrous capsule of the joints. I. External surface of any bone is, as a rule, covered by a membrane called periosteum. II. In long bones, only the diaphysis is covered by periosteum. It is present as far as epiphyseal line. Here it is continuous with the capsule of the joint.

1 General Anatomy

Tendon

Exam-Oriented Anatomy

10

b. Periosteum is absent in I. Bones covered with articular cartilage, II. Epiphyses of long bones, and III. Sesamoid bone. c. Variation of thickness: It is related to age. It is more vascular and thicker in children than adult.

General Anatomy

1

d. Factors keeping the periosteum close to the bone. I. Sharpey’s fibres are very dense at the attachments of tendon and ligaments. II. Blood vessels: They run from periosteum to the bone. They supply the bone substance and the marrow. B. Structure of periosteum (Fig. 1.10): It consists of 2 layers

Fig. 1.10: Periosteum

a. Outer fibrous layer: It is made up of densely packed fibres with some connective tissue cells. It acts as a limiting membrane. It sends bundles of collagen fibres into the bone. These are perforating fibres of Sharpey. I. They anchor the periosteum. II. They are particularly strong at the attachments of tendons or ligaments. III. The ends of long bones are covered with the articular cartilage except distal end of terminal phalanges. b. Deeper vascular layer: It contains I. Blood vessels, and II. Cells: They are i. Osteoblast cells: They are bone-forming cells. They lay down new bone on the surface of the shaft. ii. Osteoclast cells: They are bone-destroying cells. C. Variation of attachment of periosteum to bone: Attachment of periosteum varies with bone and age. a. In relation to type of bone. I. In long bones, it is more closely connected at the i. Extremities of long bones, ii. Prominences, iii. Pressure points, and iv. Over the areas to which the tendinous attachments are present. II. On flat bones, it is less adherent. b. In relation to age: In early life, it invests loosely than in adult

Skeleton

11

D. Fate of periosteum a. At the ends of bone, it continues as fibrous capsule. b. The anterior longitudinal ligament blends with the periosteum and loses its identity in the middle of the sacrum. E. Blood supply: It is mainly supplied by periosteal vascular plexus. These are the branches of muscular arteries.

G. Lymphatic : Lymphatic vessels are abundant in the periosteum. 2. Functions of periosteum A. Osteogenic, B. Protective, C. Nutritional, D. Growth of the bone, and E. Repair of bone. 3. Applied anatomy  If periosteum is removed, blood supply of the bone is lost. The bone underlying periosteum undergoes degeneration and death.  Position of nutrient foramen of fibula is important clinically. When obtaining a graft surgically, the periosteum and nutrient artery are generally removed with the piece of bone. This helps graft to remain alive when transplanted to another site.  When bone is fractured, the blood vessels and periosteum are damaged. These vessels bleed, and clot is formed between the broken ends of the fractured bone. It is called fracture haematoma.  The periosteum is thick over the mandible. In fracture of mandible, the fractured bones are not displaced because of thick periosteum.  Pain in Paget’s disease is believed to result from the stretching of the periosteum.  The inflammation of periosteum results in local pain and tenderness. SN-5

Epiphysis

(Epi—above, physis—growth) Introduction: The segment of bone which develops from secondary centre is called epiphysis. Secondary centre is one which develops after birth. 1. Classification A. Based on number of epiphysis (structurally). a. Simple: Ends of long bone develop from many epiphyses. They fuse independently with shaft, e.g. femur.

1 General Anatomy

F. Nerve supply : It has rich nerve supply through somatic nerves. They are sensory nerves. They carry pain fibres. This is the reason why fractures are extremely painful.

Exam-Oriented Anatomy

12

b. Compound: The ends of bone develop from many centres and these centres unite to form a single epiphysis. The single epiphysis subsequently fuses with shaft, e.g. head of humerus. B. Based on functions (Table 1.2) a. Pressure epiphysis b. Traction epiphysis

General Anatomy

1

Table 1.2: Comparison between pressure epiphysis and traction epiphysis Particulars

Pressure epiphysis

Traction epiphysis

Definition

It is a protective cap to the metaphysis.

Develop

As a result of transmission of weight.

As a result of pull of muscle

Takes part

In formation of joint (articular)

Does not take part in the formation of joint (non-articular)

Develops from

Secondary centre

Secondary centre

Covered by

Hyaline cartilage

Not covered by hyaline cartilage

Centre of ossification

Appears earlier

Appears late

Examples

• Upper end and lower end of humerus, • Radius, • Femur, and • Tibia

• Greater and lesser tubercle of humerus, • Greater and lesser trochanter of femur, • Radial tuberosity, • Tibial tuberosity, • Mastoid process, and • Styloid process

C. Atavistic (a great grandfather's grandfather) epiphysis: In the initial part of evolution, some part/s of bone/s were isolated bones. They were getting nutrition from the adjacent bones. In later part of evolution, such bone/s fuse/s with the adjacent bones and form part of the bone. Such bones are called atavistic bones. a. Coracoid process of scapula b. Os trigonum: It is triangular bone present at the back of talus. Sometimes it occurs as independent bone. D. Aberrant epiphysis (wandering, diverging from an accepted standard, away from normal): The miniature long bones have only one epiphysis. It is usually at distal end of the miniature long bone except for the 1st metacarpal which is present at proximal end. Sometimes, some of the metacarpals, metatarsals may have additional epiphysis/es which are called aberrant epiphysis/es. Examples are: a. Distal end of 1st metacarpal. b. Proximal end of 2nd metacarpal and 2nd metatarsal c. Proximal end of 5th metacarpal and 5th metatarsal

Skeleton

13

2. Applied anatomy

SN-6

Diaphysis

(Dia—in between, physis—growth) Introduction: It is the elongated part of long bone present between two growing ends. It develops from one primary centre. It forms the shaft of long bone (Fig. 1.11).

Fig. 1.11: Parts of a young long bone

1. Blood supply is mainly by nutrient artery, a branch of regional (of the respective region) artery. The direction of nutrient artery is opposite the direction of growing end. 2. Structure: It is described as: A. Periosteum: It is compact and strong. It is adherent only to the shaft of long bone. It is fibrous in nature. B. Inner: It is spongy and site of erythropoiesis. 3. Growth A. Height by interstitial growth. B. Thickness by appositional growth. 4. Applied anatomy Infection of the bone causes osteomyelitis. SAQ-2

Metaphysis

(Meta—end, physis—growth) Introduction: It is the epiphyseal end of diaphysis. It is the peripheral part of the shaft which is in contact with epiphyseal plate of cartilage.

1 General Anatomy

 The head of the femur receives blood supply from the epiphyseal artery. It pierces the epiphyseal cartilage. In case of separation of epiphyseal plate, from the neck of femur, there is a necrosis of head due to loss of blood supply.  The artery supplying the upper end of the tibia does not pierce the epiphyseal plate. Hence, separation of the upper end will not result in loss of blood supply in the upper end.

Exam-Oriented Anatomy

14

General Anatomy

1

1. Characters A. It is most a. Active part of bone b. Vascular part of bone, flooded in the lake of blood. B. It is the site of a. Attachment of tendons, and ligaments, b. Maximum pull, stress, strain and tension, and c. Maximum growth. 2. Types of metaphysis A. Intracapsular a. Metaphysis is present inside the capsule. b. Examples: Upper and lower ends of I. Humerus, and II. Femur B. Extracapsular a. Metaphysis is present outside the capsule. b. Examples: Upper and lower ends of I. Radius, and II. Tibia 3. Blood supply: It is by following arteries A. Nutrient artery, B. Periosteal artery, and C. Juxtaepiphyseal artery. 4. Applied anatomy  Metaphysis is susceptible to infection in the immature bone.  Infection of long bone primarily affects metaphysis. The nutrient arteries in the region of metaphysis form hairpin bend. The constricted area of nutrient arteries may get blocked by thrombus. It results in necrosis. It is the common site of osteomyelitis in children.  Infection can reach through the intracapsular metaphysis and cause septic arthritis.  Since muscles, ligaments and joint capsules are attached close to metaphysis, this is likely to be damaged by sheering strain of the muscle.  It is the region favouring haematogenous spread of infection. SN-7

Blood Supply of the Long Bone

1. The blood supply of long bone (Fig. 1.12) is by following arteries A. Nutrient artery a. Features I. It is a branch of artery of the region.

Skeleton

15

General Anatomy

1

Fig. 1.12: Blood supply of long bone

II. Its direction is away from growing end. III. The direction of the nutrient foramen (Table 1.3) is decided by the slogan. “Towards the elbow I go, and away from the knee I flee.” Table 1.3: Direction of the nutrient foramen (Fig. 1.13) Bone

Direction of nutrient foramen

Humerus

Downward

Radius, ulna

Upward

Femur

Upward

Tibia, fibula

Downward

Fig. 1.13: The arrows indicate the directions of the nutrient foramina in long bones of upper and lower limbs

Exam-Oriented Anatomy

16

General Anatomy

1

b. Peculiarities: It is tortuous before it enters the nutrient foramen for following reasons I. For the uniform distribution of blood, and II. To avoid rupture during contracting and relaxation of the muscle. c. Number: It is usually one except in femur which has two nutrient foramina which transmit arteries. d. Course I. It enters the compact bone through nutrient foramen situated in the middle of shaft. II. It divides into ascending and descending branches into the medullary cavity. III. Each ascending and descending branch divides into many small branches which turn down to form a hairpin loop. e. It anastomoses with I. Periosteal artery, II. Metaphyseal artery, and III. Epiphyseal artery. f. Distribution: It supplies I. The inner two-thirds of compact bone, II. The spongy bone, and III. Haversian system of less than 2 mm diameter. B. Metaphyseal artery a. Arises from anastomosing arteries around joint. b. Enters metaphysis through joint capsule. c. It shows looping pattern during growth of bone. C. Epiphyseal artery: Divides into two types—depending upon mode of blood supply (Table 1.4). Table 1.4: The course of the epiphyseal artery at the upper end of femur and tibia Particulars

Articular cartilage and epiphyseal cartilage are not continuous

Articular cartilage and epiphyseal cartilage are continuous

Mode of distribution

Supplies epiphysis without piercing epiphyseal cartilage

Supplies epiphysis after piercing the epiphyseal cartilage

Example

Upper end of tibia

Upper end of femur

Applied anatomy

Artery is not vulnerable for injury in epiphyseal separation. No vascular necrosis

Artery is vulnerable for injury in epiphyseal separation. It produces avascular necrosis in epiphyseal separation

D. Periosteal artery: It enters bone through Volkmann’s of haversian system. It supplies outer one-third of the compact bone. It is branch of muscular arteries. E. Muscular artery: It is a branch of muscular artery supplying adjacent muscles. F. Endosteal artery: It supplies the inner surface of the bone.

Skeleton

17

2. Applied anatomy  Osteomyelitis: The small embolus blocks the nutrient arteries at the site of hairpin bend. The distal part of the bone results into avascular necrosis. This condition is called osteomyelitis.  Shaft of long bone is affected in congenital syphilis. Growing End

1. The active end of the long bone is called growing end. It is plate of cartilage between diaphysis and epiphysis. Examples: All long bones. 2. Features A. The part of the bone which develops from secondary centre is called epiphysis. The epiphysis which appears first and fuses with the diaphysis (shaft) last is called growing end. B. Each bone has two epiphyseal ends. a. Growing end b. Non-growing end • Growing end does I. More work, II. For longer time, and III. Faster. • The non-growing end does I. Less work, II. For shorter time, and III. Slow. C. Bone increases in length at growing end. D. The growing end grows longer time and more rapidly than the other end. E. The growing end is opposite to the direction of nutrient foramen. The direction of nutrient foramen is decided by a slogan. “Towards the elbow I go, and away from the knee I flee”. Table 1.5 shows the growing end of different long bones. Table 1.5: The direction of nutrient foramen and growing end of long bones Bone

Direction of nutrient foramen

Growing end

Humerus

Downward

Upper end

Radius, ulna

Upward

Lower end

Femur

Upward

Lower end

Tibia, fibula

Downward

Upper end

3. Applied anatomy  The knowledge of growing end of the concerned long bone is necessary for surgeons to manipulate the space. The situation arises when a boy/girl meets an

1 General Anatomy

SAQ-3

Exam-Oriented Anatomy

18

General Anatomy

1

accident. In a fracture of limbs, accompanied by severe infection, there are chances of rapid spread of infection. In rapidly and uncontrolled infection, amputation is advised to prevent the spread of infection. The lower end of the femur, being growing end, may continue to grow and pierce the skin and protrude out. To avoid such consequences, surgeon keeps extra space to accommodate the growth of bone.  Damage to the growing end during growth leads more deformity than the damage to the less growing end. SAQ-4

Primary Centre of Ossification

Introduction: It is the centre from which the elongated shaft of the bone ossifies. 1. Appearance: The primary centre appears before birth. 2. Examples A. Shaft of all long bones, and B. Short bones like talus, calcaneus and cuboid. 3. Exception: Carpal and tarsal bones, the centre for which appears after birth. SAQ-5

Secondary Centre of Ossification

Introduction: The centre of the long bone which appears after birth is called secondary centre. 1. Example A. Ends of all long bones, B. Greater trochanter of femur, and C. Greater tubercle of humerus. 2. Gender variation: Secondary centres tend to appear earlier in females males . 3. Exception A. Lower end of femur, and B. Upper end of tibia, the centre for these bones appear at birth.

than

4. Applied anatomy The secondary centre for lower end of femur or upper end of tibia appears just after birth. This fact is used in determining the dead born child with the viable newborn. This is confirmed by taking the X-ray of knee joint. Presence of centre at lower end of femur or upper end of tibia confirms viability of child and exclude stillbirth. Please note, absence of secondary centre does not exclude viability.

Joints

SN-8

2

Classification of Joints

Joints are classified depending upon: A. Structure, B. Function, and C. Region. A. Structure of binding material a. Fibrous joint: Bones are kept together by fibrous tissue. They are subclassified depending upon nature of fibres I. Suture: The bones are kept together by a thin fibrous tissue or ligaments. II. Syndesmosis: The bones are kept together by fibrous tissue which is in the form of band or interosseous membrane. III. Gomphosis: The bones are kept together by fibrous tissue which is in the form of periodontal membrane. b. Cartilaginous joint: Bones are kept together by cartilage. They are subclassified depending upon the type of cartilage I. Primary cartilaginous joints or synchondrosis II. Secondary cartilaginous joints or symphysis c. Synovial joint: Bones are kept together by synovial fluid. B. Function: They are subclassified depending upon degree of mobility. a. Synarthroses are fixed joints at which there is no movement. The articular surfaces are joined by tough fibrous tissue. Often the edges of the bones are fixed into one another as in the sutures of the skull. b. Amphiarthroses are joints at which slight movement is possible. A pad of cartilage lies between the bone surfaces, and there are fibrous ligaments to hold the bones and cartilage in place. The cartilages of such joints also act as shock absorbers, e.g. the intervertebral discs between the bodies of the vertebrae, where the cartilage is strengthened by extra collagen fibres. 19

20

General Anatomy

1

Exam-Oriented Anatomy

c. Diarthroses or synovial joints are known as freely movable joints. In some joints, the movement is restricted by the shape of the articulating surfaces and by the ligaments which hold the bones together. These ligaments are of elastic connective tissue. The bones forming the synovial joint have articular surfaces. These are covered by articular cartilage. There is fluid, produced by the membrane lining the fibrous capsule. It is called synovial membrane. The fluid produced by synovial membrane is called synovial fluid. It spreads inner surface of the cavity. It acts as a lubricant. It produces free movements. C. Regional a. Skull type: Immovable. b. Vertebral type: Slightly movable. c. Limb type: Freely movable. SN-9

Fibrous Joints

In fibrous joints, the bones are joined by fibrous tissue. These joints are either immovable or permit a slight degree of movement. These can be grouped in the following three subtypes. 1. Sutures (Fig. 2.1): These are peculiar to skull, and are immovable. According to the shape of bony margins, the sutures can be: A. Plane, e.g. internasal suture B. Serrate, e.g. interparietal suture C. Squamous, e.g. temporoparietal suture D. Denticulate, e.g. lambdoid suture E. Schindylesis type, e.g. between rostrum of sphenoid and upper border of vomer. 2. Syndesmosis: The bones are connected by the interosseous ligament, e.g. inferior tibiofibular joint (Fig. 2.2).

Fig. 2.1: Sutures

Fig. 2.2: Fibrous joint—inferior tibiofibular joint

3. Gomphosis (peg and socket joint). Example: Root of the tooth in its bony socket (Fig. 2.3).

21

Fig. 2.3: Gomphosis

SN-10

Suture

(Suture—stitch, seam) Introduction: Joints of skull are connected by fibrous tissue. 1. Functions A. They allow the growth of brain in the cranial cavity. B. They help moulding of head during labour. 2. Movement: No movement. 3. Types: Depending upon articular margin, they are subdivided into: A. Plane (Fig. 2.4): Margins are straight, e.g. a. Interpalatine b. Intermaxillary (Fig. 2.1) c. Palatomaxillary (Fig. 2.1).

Fig. 2.4: Plane sutures

B. Serrate (Fig. 2.5A and B) (saw): Margins are wavy (saw-like), e.g. a. Sagittal suture b. Coronal suture. C. Denticulate: The articulating margins resemble teeth. The tips are broader than the roots to have effective interlocking, e.g. lambdoid suture (suture between parietal and occipital bone, Fig. 2.6). D. Squamous (Fig. 2.7): The articulating margins are bevelled, e.g. temporoparietal E. Schindylesis (splinting a piece of wood): The ridged bone fits into a groove, e.g. rostrum (beak) of sphenoid overlapped by ala (wing) of vomer (Fig. 2.8).

1 General Anatomy

Joints

22

Exam-Oriented Anatomy

General Anatomy

1 Fig. 2.5A and B: (A) Cranial vault showing serrate and dentate suture; (B) Serrate suture

Fig. 2.6: Denticulate suture

Fig. 2.7: Squamous suture

Fig. 2.8: Schindylesis

F. Gomphosis (wedge-shaped nail or bolt): Peg and socket type of joint, e.g. tooth and socket (refer to Fig. 2.3). G. Limbus (border): Borders are mutually ridged or serrated. 4. Age changes A. Ossification of sutural membrane starts at the age of 20 years and is slow. B. Ossification completes at late twenties. SN-11

Syndesmoses

(Syn—fusion, desmos—band) Introduction: Bony surfaces are joined together by interosseous membrane or ligament. 1. Characters A. It is a type of fibrous joint. B. The bones are kept together at a distance by interosseous membrane. C. The interosseous membrane persists throughout life. 2. Movement: Slight degree of movement is possible, e.g. Inferior tibiofibular joint, Middle radioulnar joint, and Posterior sacroiliac joint.

IMP

Joints

SN-12

23

Primary Cartilaginous Joint (Synchondrosis)

1 General Anatomy

1. Characters (Fig. 2.9) A. The articulating surfaces are covered by a hyaline cartilage. B. They are immovable and strong. C. They are temporary in nature. D. Cartilaginous plate is replaced by bone synostosis.

Fig. 2.9: Primary cartilaginous joint (synchondrosis)

2. Example:

First, CDSS

First chondrosternal joint Costochondral Diaphysis and epiphysis of long bone Spheno-occipital Sternoxiphisternal SN-13

Secondary Cartilaginous Joint (Symphysis)

Introduction: The articulating surfaces of bones are covered by a hyaline cartilage. These hyaline cartilages are separated by a fibrocartilage (Fig. 2.10). 1. Characters: The thickness of fibrocartilage is directly related to range of movements. 2. Functions of secondary cartilaginous joints. They A. Act as shock absorber. B. Help in flexibility. C. Help in weight transmission. 3. Site: All midline joints of body except A. Symphysis menti (atypical and temporary joint). B. Joint between sternum and xiphoid. 4. Fate: Movements are limited.

24

Exam-Oriented Anatomy

General Anatomy

1 Fig. 2.10: Secondary cartilaginous joint

5. Duration: Persists throughout life. 6. Example:

IMPS

Intervertebral joint Manubriosternal Pubic symphysis Sacral joint SN-14

Typical Synovial Joint

Introduction: The synovial joints have free movements. There is a cavity between the articulating bones. Hence, they are also called cavitatory joint. 1. Characters: Synovial joints are characterized by following features (Fig. 2.11): A. Articular cartilage: Articular surfaces are covered by a layer of hyaline cartilage.

Fig. 2.11: Structure of a simple synovial joint

Joints

25

B. Fibrous capsule a. It consists of longitudinal and interlacing bundles of white connective tissue fibres. It is attached to articulating ends of the bones and forms as a cuff. It encloses a joint cavity. b. It is pierced by blood vessels and nerves.

d. It has rich nerve supply, hence it is highly sensitive. C. Ligaments: It is strengthened by a. Accessory ligaments, and b. Muscles surrounding the joint. D. Synovial membrane a. Characters I. It lines the inner surface of fibrous capsule. II. It is deficient at articular surfaces. III. It secretes hyaluronic acid which is responsible for viscosity of the synovial fluid. IV. The viscosity of the fluid varies with the movements. V. The quantity of the fluid also varies. The knee which is the largest joint contains 0.5 ml. b. Functions of synovial fluid I. Lubrication, and II. Nutrition. E. Joint cavity: All synovial joints are enclosed in a joint cavity. F. Movements: The joint is capable of varying degrees of movements. 2. Functions: Varying degrees of movements. 3. Applied anatomy  Tuberculosis and gonococcal infection affects synovial joint.  More than one joint may have same nerve supply, e.g. hip and knee joints supplied by obturator nerve. Hence, diseases of one joint may cause referred pain to other joint. SN-15

Classification of Synovial Joint

Synovial joints are subclassified depending upon axis, number of bones, presence of ABCS cartilage and the shape of articulating surfaces 1. Axis A. Plane joints: No axis. B. Uniaxial: Movements in only one axis. It is subclassified depending upon the direction of axis.

1 General Anatomy

c. It acts as watch dog, i.e. it prevents the excessive movements and protects the joint from dislocation.

26

General Anatomy

1

Exam-Oriented Anatomy

a. Hinge variety, if the direction of axis is horizontal. For example I. Elbow joint II. Knee joint III. Ankle joint b. Pivot variety, if the direction of axis is vertical. For example I. Superior and inferior radioulnar joints II. Atlantoaxial joint. 2. Number of bones A. Simple, if the number of articulating bones is two. For example a. Shoulder joint b. Hip joint. B. Compound, if the number of articulating bones is more than two. For example a. Wrist joint b. Knee joint. 3. Presence of cartilage: Complex joint, when joint cavity is divided by an intra-articular disc into upper/lower, medial/lateral compartment it is called complex joint, e.g. A. Temporomandibular joint, B. Acromioclavicular joint, and C. Sternoclavicular joint. 4. Shape of the articulating bones : The articular surface of one bone is A. Ball-and-socket or spheroidal joints spherical and it fits into socket of corresponding bone. Examples are: a. Shoulder joint, b. Hip joint, c. Talonavicular joint, and d. Incudostapedial joint : The articular surface of one bone is convex and B. Sellar or saddle joints concave and reciprocating surface is concave convex. Examples can be recollected by funny Hindi sentence which is followed by body gesture. The sentence is Mera dimag ghutane me nahi hai (esjk fnekx ?kqVuks esa ugh gSA) meaning “My mind is not Kneeling”. The words of the sentence represent as: Mera represents “sternoclavicular joint”. Dimag represents “temporomandibular joint and incudomalleolar joint”. Ghutane me represents “patelofemoral joint”.

27

Joints

Nahi represents “calcaneocuboid joint”. Hai represents “joint of the thumb” C. Condylar or bicondylar joints

:

Examples are: a. Knee joint, and

1 General Anatomy

b. Temporomandibular joint. D. Ellipsoid joint a. Atlanto-occipital joint, b. Wrist joint, and c. Metacarpophalangeal joint. SN-16

Pivot Joint

(Pivot—a pin on which anything turns) Introduction: It is a uniaxial (transverse axis) synovial joint (Table 2.1). Table 2.1: Comparison of superior radioulnar joint with median atlantoaxial joint

Joint

Superior radioulnar joint

Median atlantoaxial joint

• Bones

• Radius and ulna

• Atlas and axis vertebrae

• Articulating surfaces

• Head of radius and radial notch on ulna

• Posterior surface of body of atlas and anterior surface of odontoid process of axis

• Axis (vertical)

• Radius

• Odontoid process of axis vertebra

• Formation of ring

• Annular ligament

• Posterior arch of atlas

• Structure of ring

• Bone and fibrous tissue

• Bone

• Mechanism during movement

• Ring • Fixed • Axis • Moving • Movements • Supination, pronation

• Moving • Fixed • Side-to-side movement (no movement)

• Range of movements

• More

• Less

• Applied anatomy

• In children, subluxation of superior radioulnar joint is common

• Death in hanging is due to rupture of transverse ligament of atlantoaxial joint

3 Muscles

OLA-1

What is a sarcomere?

1. Features A. A sarcomere is segment of the fibre between successive Z bands. B. It is the smallest structural and functional contractile unit of the muscle. C. Repeating contractile units are seen along the entire length of each myofibril. D. Highly characteristic features of the sarcoplasm of skeletal and cardiac muscle fibres. It is 2.5 long. E. It contains a. “A” band, and b. 1/2 of “I” band. F. Myofibril is the finer structural and functional unit of the sarcomere. 2. The sarcomere has a central dark and peripheral light band. 3. The dark staining band contains thick myosin filaments. 4. The light staining band contains thin actin filaments. 5. Actin and myosin filaments are precisely aligned. 6. They are stabilised within individual myofibrils. The sarcomeres are stabilised by accessory proteins. 7. The thin actin filaments are bound to the protein called -actinin. This binds them to the dense Z line (band). 8. The thick myosin filaments are anchored to the Z line by the very large protein called titin. Titin keeps myosin filament in the centre of the Z line. It acts like a spring between the end of the myosin filament and the Z line. SAQ-6

Pennate Muscles

1. Unipennate (Fig. 3.1A): The fleshy fibres have a linear or narrow origin. The appearance is that of 1/2 of a feather;

28

Muscles

29

A. Examples a. Extensors I. Extensor digitorum longus II. Peroneus tertius b. Flexor: Flexor pollicis longus c. Adductor: Palmar interossei

General Anatomy

1

Fig. 3.1A to D: Pennate muscles

2. Bipennate (Fig. 3.1B): The fleshy fibres arise from a long broad surface, e.g. A. Muscle of thigh: Rectus femoris B. Muscles of sole: a. Flexor hallucis longus, b. Dorsal interossei, and c. Peroneus longus (Fig. 3.1E and F) 3. Multipennate (Fig. 3.1C): The septa extend into the origin and insertion. It gives the appearance is that of many feathers, e.g. A. Subscapularis B. Deltoid (acromial fibres) 4. Circumpennate (Fig. 3.1D), e.g. tibialis anterior

E

F

Fig. 3.1E and F: (E) Three bipennate muscles resembling three plumes; (F) Peacock plume

Exam-Oriented Anatomy

30

SN-17

General Anatomy

1

Prime Movers (Agonists)

Introduction: The muscles which initiate and carry out the desired action by active contractions (shortening) are called prime movers, e.g. in the flexion of elbow joint, the biceps muscle is prime mover. 1. A muscle may perform all the 4 roles under different situations. Flexor carpi ulnaris is a prime mover in flexion at the wrist and an antagonist in extension. It acts as a fixator in flexion of the thumb and is a synergist in extension of the thumb. 2. Contraction of muscle may be isotonic or isometric (Table 3.1). Table 3.1: Types of contraction of the muscle Type of contraction

Tone

Length

Movement

Isotonic

Equal

Changes

Yes

Isometric

Changes

Equal

No

3. Isotonic (iso—equal, tonic—tone): During contraction, the length of the muscle decreases to 1/3rd and the tone of the muscle remains unchanged. It is associated with the movement, e.g. in flexion of the elbow joint, length of biceps is decreased but the tone remains unchanged. 4. Isometric (iso—equal, metric—measurement): During contraction, the length of muscle fibre remains unchanged but the tone of the muscles changed, e.g. after semiflexion of the elbow joint against resistance, the length is not decreased but tone is changed. 5. Following are the forces opposing the action of the muscle A. Antagonist B. Gravity: It is a valuable aid to some movements, depending upon the position of the limb of the body, e.g. on raising the arm from the side, the deltoid is a prime mover at the shoulder and the gravity (certainly if there is a weight in the hand) is sufficient to lower the arm. C. Connective tissue resistance. D. Active resistance. 6. The range and force of movement is directly proportional to A. Length of the fibres, and B. Number of the fibres. 7. Law of Sherrington: When the agonists or prime movers are active, antagonists are inhibited by reciprocal innervation. When a muscle receives a nerve impulse to contract, its antagonist muscle receives simultaneously an impulse to relax. Flexion of wrist joint is opposed by the extensor. 8. Action of paradox: When a prime mover helps opposite action by active controlled lengthening against gravity, it is known as action of paradox, e.g. putting a glass on a table is assisted by gravity but controlled by gradual, active lengthening of biceps. SN-18

Antagonists

Introduction: They oppose the prime movers. They help the prime movers by active controlled fractional relaxation, so that the desired movement is smooth and precise.

31

Thus, the antagonists cooperate rather than oppose the prime movers. This is due to reciprocal innervation of the opposite groups of muscles, regulated by the spinal cord through stretch reflex. Antagonist muscles pass over the opposite side of the axis of rotation. Flexion of wrist joint is done by flexor carpi radialis and ulnaris, which is opposed by extensor carpi radialis longus, brevis and extensor carpi ulnaris. • Flexion of digit is done by efficient extension of wrist joint. This is done by flexor digitorum superficialis and profundus helped by extensor digitorum, which is antagonist. Box 3.1 Note: In addition to the above description, please add points 2, 3, 4, 5 and 6 of prime movers. SN-19

Fixators

Introduction: The accessory muscles which steady the proximal joint to bring the desired action on the joint under consideration. In flexion of wrist joint, the rotator cuff (subscapularis, infraspinatus and teres minor) fix the shoulder joint, to have the smooth movement at wrist joint. Box 3.2 Note: In addition to the above description, please add points 2, 3, 4, 5 and 6 of prime movers. SN-20

Synergists

Introduction: Muscles that assist prime movers are called synergists. When a prime mover passes over more than 1 joint, certain muscles are required to steady the unstable joint such muscles are called synergists. Muscles cross the same site of axis of rotation. 1. During flexion of elbow, biceps muscle brings flexion of elbow assisted by brachialis which is synergist. 2. Flexion of digit is efficiently done by efficient extension of wrist joint. This is done by flexor digitorum superficialis and profundus helped by extensor digitorum which is antagonist. 3. In most instances, motion at a joint is initiated by one set of synergistic muscles and brought to close by the antagonists. For example, controlled flexion of the forearm at the elbow joint is initiated by flexor muscles and slowed or stopped at any desired position by extensor muscles. 4. Simultaneous contraction of both synergists and antagonists produces maximal joint stability (dynamic stability) with a little or no movement. Box 3.3 Note: In addition to the above description, please add points 2, 3, 4, 5 and 6 of prime movers.

1 General Anatomy

Muscles

4 Cardiovascular System

OLA-2

Enumerate 4 arteries commonly used for palpating peripheral pulsations

1. Upper limb—radial artery 2. Lower limb A. Femoral artery B. Dorsalis pedis artery 3. Head, neck and face—superficial temporal artery SN-21

Anastomosis

Introduction: It is a precapillary or/and postcapillary communication of vessels. The blood passing through these communications is called collateral circulation. 1. Types: The anastomosis may be of following types A. Arterial anastomosis: Anastomosis between the two arteries or branches of the two arteries. It is further divided into a. Actual arterial anastomosis: The main arteries communicate with each other. In this, the blood spurts through the cut ends on both the sides, e.g. I. Circle of Willis II. Palmar arches III. Labial artery (branch of facial artery). b. Potential arterial anastomosis: Communication takes place between the terminal arterioles. Such communication is gradually through collateral circulation. Blockage of main artery may fail to compensate the blood, e.g. I. Coronary arteries II. Cortical branch of cerebral arteries. B. Venous anastomosis: It is the communication between veins or tributaries of veins, e.g. dorsal venous arch of foot and hand. C. Arteriovenous anastomosis (shunt): It is the communication between an artery and vein. When an organ is active these shunts are closed, and the blood circulates through capillaries. It is divided into simple shunts, e.g. skin of nose, lips and external ear. 32

Cardiovascular System

33

D. Specialized, e.g. Skin of digital pads and nail beds. These form a number of small units called glomeruli. E. Preferential through channels: The blood passes through the capillary network and they form microcirculatory units. 2. Functions: The nutrition of the organ is maintained, in case of blockage of the artery. End Arteries

Introduction: The arteries which do not communicate with neighbouring arteries are called end arteries. 1. Types: They are of following types A. Functional end arteries. a. These are not true end arteries. b. Structurally, they communicate, c. But the blood flowing through these communication channels fail to meet the required demand, e.g. coronary arteries. B. Structural end arteries a. There is no structural communication between these arteries. b. These are true end arteries, e.g. (Fig. 4.1) I. Central artery of retina, II. Central arteries of the cerebrum, III. Renal arteries, and IV. Arteries of spleen.

Fig. 4.1: End artery

2. Applied anatomy  Occlusion of an end artery causes serious nutritional disturbances resulting in death of tissue supplied by it, e.g. in case of blockage of right coronary artery, the muscles of the heart undergo ischaemia and results into myocardial infarction.  In case of rupture of central artery of retina, the blood supply of eyeball is lost and person becomes blind.

1 General Anatomy

SN-22

Exam-Oriented Anatomy

34

SN-23

Bursa

(Bursa—purse)

General Anatomy

1

Introduction: It is a pocket-like space lined by synovial membrane containing synovial fluid. 1. Types A. Communicating: Some bursae communicate with joint cavity, e.g. subscapular bursa of shoulder joint. B. Non-communicating: For example, infrapatellar bursa of knee joint. 2. Functions A. It reduces the friction between two mobile and tightly opposed surfaces. B. It permits complete freedom of movement within limited range. 3. Classification: It is classified depending upon the situation A. Subcutaneous: Deep to the skin. B. Subtendinous: Deep to the tendon, e.g. subscapular bursa: It communicates with the shoulder joint. It lies deep to scapula and present between superior and inferior glenohumeral ligaments. C. Submuscular: Deep to the muscle, e.g. semimembranosus bursa: Deep to semimembranosus muscle. D. Subfascial: Deep to the fascia. 4. Applied anatomy  Bursitis: Inflammation of bursa is called bursitis, e.g. olecranon bursitis (miner’s elbow, student’s elbow): Inflammation and enlargement of the bursa over the olecranon process of ulna. This bursa lies between olecranon process and the overlying skin.  Clergyman’s knee: It is present below patella and is superficially placed. The person gets pain in movement of knee joint.  Morrant Baker’s cyst: The swelling behind the knee is caused by escape of synovial fluid which lies in space or membrane. It is prominent during extension and disappears during flexion. It is associated with the tendons of semimembranosus or gastrocnemius.  Housemaid’s knee: The bursa between the skin and anterior surface of patella is called prepatellar bursa and it is inflamed in housemaid.  Weaver’s bottom: The bursa over ischial tuberosity is inflamed in weavers.

2 General Histology • Epithelium • Connective Tissue • Cartilage • Bone • Muscle • Blood Vessels • Lymphoid Tissue

Attention Please All the texts in boxes are not to be written in the examination.

5 Epithelium

SAQ-1

Simple Squamous Epithelium

Introduction: The cells of the simple squamous epithelium are flat. They have length, breadth but no thickness (Fig. 5.1).

Fig. 5.1: Simple squamous epithelium

1. Features: Cells of simple squamous epithelium have following features—“ABC”. They A. Are Avascular B. Rest on Basement membrane. C. Are Compactly arranged. Cells are separated by minimal amount of intercellular substance. 2. Morphology A. Cells are arranged in single layer. They are irregular which are thin and platelike. B. The nuclei are round and centrally situated. C. The cell junction is marked by zonulae occludentes. D. Surface view a. Cells look polygonal, or mosaic. b. Nuclei are bulging. 3. Functions A. It helps in transport of material across the cell. B. The tight junctions between the cells prevent entry of various substances through them. C. It facilitates movement of viscera in serous cavities. SAHEB. 4. Sites or examples of simple squamous epithelium: A. Serous membranes like a. Pleura (covering of lungs), b. Pericardium (covering of heart), and c. Peritoneum (covering and the abdominal organs and abdominal cavity). 37

Exam-Oriented Anatomy

38

B. Alveoli of lung. C. Loop of Henle—descending and ascending loop of Henle in kidney. D. Endothelium of blood vessel. E. Bowman’s capsule. SN-1

Simple Columnar Epithelium

Introduction: The cells are column-like or rectangular (on vertical section) (Fig. 5.2). 1. Features A. The cells of the simple columnar epithelium are arranged in single layer. B. All the cells touch basal lamina (basement membrane). C. The height of the cells is more than width. D. The nuclei are vertically elongated.

General Histology

2

Fig. 5.2: Types of epithelium Table 5.1: Features of subtypes of columnar epithelium Particulars

Simple

Ciliated

Microvilli

• Size of cell

• Tall

• Tall

• Tall

• Nucleus

• Elongated and nearer to the basal surface than luminal surface

• Elongated

• Elongated

• Peculiarities • Functions

— • Absorption • Secretion

• Cilia present • Movements of particles

• Microvilli present • Movement of particles

• Situation

• Lining epithelium of – Gastrointestinal tract and – Gallbladder

• Bronchi, bronchioles • Central canal of spinal cord • Efferent ductules of rete testis. • Fallopian tube

• Jejunum

Epithelium

SN-2

39

Pseudostratified Epithelium

(Pseudo—false) Introduction: The simple columnar epithelium giving appearance of stratified (multilayered) epithelium is called pseudostratified epithelium (Fig. 5.3). 1. Features A. The cells are of variable height. Some cells are short and some cells are tall. B. All cells lie on the basement membrane. C. Short cells do not reach lumen. D. The nuclei are situated in the centre of each cell irrespective of the length of the cell. E. The nuclei are arranged in more than one layer which gives impression of many layered cells.

Fig. 5.3: Pseudostratified epithelium

2. Classification: The pseudostratified epithelium is divided into following types A. Pseudostratified non-ciliated: The luminal surface of the cells does not bear cilia, e.g. epithelium of a. Male urethra, and b. Vas deferens. B. Pseudostratified ciliated columnar: The luminal surface of the cells bears cilia, e.g. epithelium of a. Upper respiratory tract, b. Trachea, and c. Larger bronchi. SN-3

Stratified Squamous Epithelium

Introduction: The multilayered epithelium having squamous (flat) cells on the top. 1. Morphology A. The deepest cells are columnar. B. The middle cells are cuboidal or polyhedral. C. The superficial cells are flat or squamous. 2. Classification: The stratified squamous epithelium is divided into following types depending upon the presence and absence of keratin (Fig. 5.4A and B).

General Histology

2

Exam-Oriented Anatomy

40

Fig. 5.4A: Stratified squamous keratinised epithelium, e.g. epidermis of skin

Fig. 5.4B: Stratified squamous non-keratinised epithelium

General Histology

2

Table 5.2: Characters of the stratified squamous epithelium—keratinised and non-keratinised Particulars

Features

Stratified squamous keratinized

Stratified squamous non-keratinized

•Superficial cells

• Viability • Nucleus • Keratin

No Absent Present

Viable Present Absent

•Function

• To prevent wear and tear

Protection

•Site

• Dry surface

• Wet surface

•Situation

• Skin • Vagina • External acoustic meatus

• Oral cavity • Tongue • Pharynx • Esophagus • Lip • Cornea

SN-4

Transitional Epithelium (Urothelium)

Introduction: The cells of the transitional epithelium are multilayered, having capacity for distension. 1. Arrangement of cell: The cells of A. Deepest row are columnar. B. Middle row are pear

shaped.

C. Superficial layer are umbrella

shaped.

2. Peculiarities A. It shows mitosis. B. The cells are multilayered (stratified). The top cells have capability of stretching (Fig. 5.5). C. The cells are embedded in lipid which prevents entry of toxins.

Epithelium

41

Fig. 5.5: (A) Transitional epithelium (relax state); (B) Transitional epithelium (stretch state)

3. Sites A. Pelvis of the kidney, B. Ureter, and C. Urinary bladder.

2

What is brown fat?

1. Definition: The adipose tissue showing many vacuoles is called multilocular adipose tissue. It is brown in colour. Hence, it is called brown fat. 2. Characters A. It is highly vascular. B. It is smaller in size as compared to unilocular. nucleus. C. It has centrally placed spherical D. It contains many mitochondria. OLA-2

Draw and label a section of a cilium

Fig. 5.6: Structure of a cilium

General Histology

OLA-1

Exam-Oriented Anatomy

42

OLA-3

Classify compound epithelium with examples

Compound epithelium is subdivided into 1. Stratified squamous A. Stratified squamous keratinised, e.g. skin B. Stratified squamous non-keratinised, e.g. oesophagus 2. Stratified columnar, e.g. moderate-sized ducts of salivary gland 3. Stratified cuboidal, e.g. secondary ovarian follicles OLA-4

What are the differences between microvilli, cilia and stereocilia? Explain with the help of diagrams Table 5.3: Differences between cilia, microvilli, and stereocilia

General Histology

2

Particulars • Motility

Cilia –

Microvilli • Motile

Stereocilia • Non-motile

• Functions

• Movements of particles

• Movement of particles

• Increase the surface area of a cell

• Situation

• Bronchi, • Jejunum bronchioles • Central canal of spinal cord • Efferent ductules • Fallopian tube

Fig. 5.7A: Stereocilia

Fig. 5.7B: Microvilli

• Free surfaces of receptor cells of – Cochlea and – Vestibular apparatus • Epithelial cells of the epididymis.

Epithelium

SN-5

43

Junctional Complexes

The structures present on the lateral and the basal surfaces of epithelium are called junctional complexes (Fig. 5.8). The epithelial cells are tightly attached to each other or to extracellular matrix by specialised junctions. 1. There are several types of cell adhesion molecules (CAMs). They are membrane proteins, responsible for the specialised junctions. 2. The proteins consist of three domains A. Intracellular binding protein: It interacts with cytoskeleton and acts as an anchor within the cell. B. Transmembrane protein: It protrudes through the plasma membrane. C. Extracellular link protein: It binds with

2 General Histology

a. Other CAMs of same type (homophilic binding) or with b. Different types of CAMs or extracellular matrix (heterophilic binding).

Fig. 5.8: Junctional complex

3. They are classified into two groups A. Calcium dependent a. Cadherins, b. Integrins, and c. Selectins. B. Calcium independent: There are of two groups a. NCAMs (neural cell adhesion molecules): Expressed by nerve cells b. ICAMs (intercellular cell adhesion molecules): Expressed by leucocytes

44

Exam-Oriented Anatomy

C. Types of junctions: Epithelial cells are tightly attached to each other by specialised junctions. These junctions are of three types a. Occluding, b. Anchoring, and c. Gap junctions. 4. Functions A. They bind the adjacent cells with each other. B. They act as a barrier.

General Histology

2

6 Connective Tissue

SN-6

Write a note on dense regular connective tissue

1. Dense connective tissue (Fig. 6.1) contains A. Thicker and densely arranged collagen fibres, B. Fewer cell types C. Fibroblasts are the most abundant. They are located between the dense collagen bundles. D. Less ground substance.

Fig. 6.1: Dense connective tissue

2. Types: Dense connective tissue are of two types A. Dense irregular connective tissue a. The collagen fibres are randomly and irregularly arranged. b. Examples I. Dermis of skin, II. Capsules of various organs, and III. Areas that need strong binding and support. B. Dense regular connective tissue a. They contain densely packed collagen fibres. b. They exhibit a regular and parallel arrangement. c. Examples I. Tendons, and II. Ligaments. 45

46

SN-7

Exam-Oriented Anatomy

Write a note on adipose tissue

1. Introduction: It is type of connective tissue. 2. Features A. It contains predominantly adipose or fat cells (Fig. 6.2). B. The cells occur singly or in groups. C. They store fat.

General Histology

2

Fig. 6.2: Fat cell

3. Sites: They are present in lipid storage organs, e.g. intestinal mesentery. 4. Types: There are two types of adipose cells. A. White adipose tissue a. Features • It is more common. • The cells are large and store lipids as a single large droplet. • The lipid stored in the adipose cells are primarily triglycerides (fatty acids and glycerol). They are derived from i. Intestinal lipoproteins ii. Very low-density lipoprotein (VLDL) from the liver. • It is i. Distributed throughout the body. ii. Highly dependent on gender and age. iii. Highly vascular as a result of high metabolic activity. b. Functions • It serves as important energy source. • It acts as i. Insulation under the skin. ii. Cushion. iii. Important endocrine organ. • These cells are only source of hormone called leptin. B. Brown adipose tissue a. Features • The cells are smaller. • It stores lipid as numerous or multiple small droplets. • It has limited distribution.

Connective Tissue

47

• It is present in all mammals. • It is regulated through sympathetic nervous system. • The amount of brown adipose tissue increases as age advances. b. Sites • Adrenal gland, • Great vessels, and • Neck. c. Functions: Main function is to supply heat to the body. It is through nonshivering thermogenesis. What are the different types of cells in a connective tissue? What are their identification points

and functions?

The main cells of the connective tissue are the 1. Fibroblasts (Fig. 6.3)

Fig. 6.3: Fibroblast

A. Identifying points a. A large, rounded vesicular nucleus. b. Prominent nucleus with abundant cytoplasm. B. Functions a. Maintain the integrity of connective tissues. b. They secrete and maintain the components of matrix. 2. Fibrocytes (Fig. 6.4)

Fig. 6.4: Fibrocyte

A. Identifying points a. Spindle

shaped cells

b. Flat nucleus B. Function: They secrete and maintain the components of matrix.

2 General Histology

SN-8

Exam-Oriented Anatomy

48

3. White adipose (fat) cells (Refer to Fig. 6.2) A. Identifying points

: Large spherical

cells with eccentric nucleus.

B. Functions: They act as a. Insulator b. Storehouse of energy c. Shock-absorbing cushion. 4. Brown adipose cells A. Identifying points a. They are smaller in size as compared to unilocular.

General Histology

2

b. They have centrally placed spherical nucleus. B. Functions: Main function is to supply heat to the body through non-shivering thermogenesis. 5. Macrophages (Macro—big, phage—to eat) (Fig. 6.5)

Fig. 6.5: Macrophage

A. Identifying points

: Large cells with a dark nucleus.

B. Functions: Phagocytosis Table 6.1: Distribution of macrophages in various organs Organ

Macrophage

• Skin

• Langerhans cells

• Bone

• Osteoclast

• Blood

• Monocyte

• Liver

• Kupffer cells

• Central nervous system

• Microglia

• Lung

• Alveolar macrophages

• Lymph nodes

• Fixed macrophages

• Inflamed tissue

• Multinucleated giant cells

Connective Tissue

49

6. Lymphocytes (Fig. 6.6)

Fig. 6.6: Lymphocyte

A. Identifying points a. They have round nucleus, which is often eccentrically placed. b. In small lymphocytes, a thin rim of cytoplasm is present around the nucleus. c. In large lymphocytes, the rim of cytoplasm is wider than in small lymphocytes.

7. Plasma cells (Fig. 6.7)

Fig. 6.7: Plasma cell

A. Identifying points

: Ovoid

2 General Histology

B. Functions a. They are involved in chronic infection. b. They help in immune mechanism.

cells with an eccentrically placed

cartwheel nucleus and a basophilic cytoplasm. B. Functions: Involved in antigenic response. 8. Mast cells (Fig. 6.8)

Fig. 6.8: Mast cell

Exam-Oriented Anatomy

50

A. Identifying points a. Large ovoid cells found along blood vessels. b. Central spherical nucleus. c. Basophilic granules in the cytoplasm. B. Functions a. Release histamine and vasoactive chemicals when exposed to allergens. b. It causes allergic reactions. 9. Neutrophils (Fig. 6.9)

General Histology

2 Fig. 6.9: Neutrophil

A. Identifying points a. These are the most abundant (50–70%). They are present in blood. b. Their nuclei have 3–5 lobes. B. Functions a. Engulf and destroy bacteria. b. They provide first line of defence against infective organisms. c. They phagocytose the microorganisms and destroy them by their enzymes. 10. Reticular cells A. Identifying points a. Stellate cells with large nucleus b. Prominent nucleolus. B. Functions: They produce reticular fibres which support lymphocytes, macrophages and other cells of the lymphoid tissue.

Connective Tissue

51

11. Eosinophils (Fig. 6.10)

Fig. 6.10: Eosinophil

A. Identifying points

OLA-5

Describe plasma cell

Refer to Fig. 6.7. 1. Area of distribution: Present in serous and mucous membrane of alimentary and lymphoid tissue. 2. Characters: Small, rounded or ovoid cells with eccentric nucleus. 3. Nucleus and cytoplasm: Deeply basophilic cytoplasm. Chromatin material in the nucleus is arranged radially and gives a cartwheel appearance. 4. Functions: Chief function is production of antibodies

2 General Histology

a. They constitute 1–5% of the leucocytes present in blood. b. The cells have bilobed nucleus. B. Functions a. Phagocytize antigen–antibody complexes during allergic reactions.

7 Cartilage

SN-9

Draw and write a note on articular cartilage

Articular cartilage

Fig. 7.1: Articular hyaline cartilage

1. Features A. The articular surfaces of the bone are not ossified and they remain as articular cartilage. B. It belongs to hyaline cartilage but differs in following aspects. a. Perichondrium is absent as it is bathed in synovial fluid. b. It does not ossify with age. 2. Histology: It shows four zones from superficial to deep surface. A. Zone I (superficial or tangential stratum) a. It contains a few rows of fibrocytes. b. Cells are small and flattened. c. Fibrocytes in deepest part are parallel to the surface. d. They have a few collagen fibres called lamina splendens. B. Zone II (transitional or intermediate stratum) a. The chondrocytes lie in a random fashion. b. Cells are large and round. 52

Cartilage

53

c. They may be single or arranged in groups and are obliquely placed. d. They lie within the lacunae. e. EM demonstrates interterritorial matrix. f. It has obliquely placed collagen fibres. C. Zone III (radiate stratum) a. Contains columns of chondrocytes in lacunae. b. They are arranged radially to the surface. c. EM shows radial collagen fibres in the interterritorial matrix.

3. Site: It lines most of the articular surfaces of synovial joints except temporomandibular joint which is lined by fibrocartilage. 4. Functions of cartilage A. It acts as a cushion and protects the bone. B. It provides smooth surfaces which prevent friction. 5. Nourishment A. It derives its nourishment from synovial fluid. B. Since the cartilage is avascular tissue, it depends on the surrounding tissue for its nourishment. It has poor healing capacity. C. This also explains why cartilage cannot become very thick, since diffusion of nutrients and gases to the deeper tissue will be insufficient. 6. Applied anatomy

 The thickness of articular cartilage varies from 1 to 7 mm (typically 2 mm) in different joints and decreases from middle to old age.  In adults, thickness does not increase in proportion to mechanical loading.  In osteoarthritis, articular cartilage becomes thinner and ultimately break. It exposes underlying bone. It is highly painful condition and leads to walking disability.  For example,  Interphalangeal joints of hand,  Hip joint, and  Knee joint.  Articular cartilages do not heal if injured, except articular cartilage situated close to synovial membranes.

2 General Histology

D. Zone IV (calcified stratum) a. They touch the subchondral osseous lamina. b. The cartilage cells die and bone formation starts on the remnants of the matrix. c. It is type of hyaline cartilage but lacks perichondrium. d. Central regions tend to be thickest on convex osseous surfaces, and thinnest on concave surfaces.

Exam-Oriented Anatomy

54

SN-10

Draw and write a note on hyaline cartilage

(Hyalos—glass, transparent)

General Histology

2

Introduction: The basic tissue which forms skeleton of some organs, e.g. larynx. 1. Types A. Articular B. Non-articular 2. Peculiarities A. It is transparent. B. It contains homogenous intracellular substance. C. It is basophilic, i.e. stains blue with H and E stain. D. The perichondrium may or may not present. 3. Structures (Fig. 7.2) A. Cells a. The cartilage cells are called chondrocytes. b. They are present in cell nests. c. They are in groups. d. The cells are kept together by dense matrix. e. The matrix around the cell nests is stained deeper and is called lacunar capsule. f. The matrix in between the cell nests is stained pale and is called interstitial matrix. B. Ground substance: It contains collagen fibres.

Fig. 7.2: Hyaline cartilage

4. Functions: It resists compressive and tensile forces. 5. Sites A. Larynx: Thyroid, cricoid, arytenoid cartilage. B. Bronchial part of nasal septum, C. Lateral wall of nose, and D. Epiphyseal plate

Cartilage

55

6. Features of hyaline (glossy) cartilage A. It has a homogeneous, opalescent appearance. B. It is firm and smooth to touch and shows considerable deformability. C. The size, shape and arrangement of cells vary with sites and age. D. Chondrocytes are flat near the surface perichondrium. E. They occupy in the cell nest. F. Each nest has two or more cells. G. Each is surrounded by a basket of fine collagen fibrils. H. The matrices surrounding the cells do not have collagen fibrils. But they are rich in proteoglycans. They exhibit basophilic and metachromatic staining. I. Examples

SN-11

Draw and write a note on fibrocartilage

Fibrocartilage 1. Occurrence A. It occurs in locations where a tough support or tensile strength is desirable Box 7.2 It is easy to remember the example of fibrocartilage. I. Imagine the structures responsible for weight transmission starting from skull to the bones of feet. i. Intervertebral disc ii. Pubic symphysis iii. Acetabular labrum iv. Meniscus of knee joint II. Imagine you are carrying weight on the extended hand i. Articular disc in wrist joint ii. Glenoid labrum iii. Articular disc in sternoclavicular joint III. You are cracking betel nut. i. Articular disc of temporomandibular joint

2 General Histology

Box 7.1 It is interesting to remember the examples of hyaline cartilage Take deep breath, and imagine the cartilages touched and affected by inspired air I. Nasal cartilage II. Alar cartilage III. Thyroid cartilage IV. Cricoid cartilage V. Trachea VI. Bronchus and VII. Costal cartilage

Exam-Oriented Anatomy

56

2. Features: It never occurs wholly alone, but merges with neighbouring hyaline cartilage or with fibrous tissue. 3. Macroscopic appearance. A. This tissue has an opaque appearance and a firm, fibrous texture. B. A perichondrium is lacking. 4. Microscopic structure (Fig. 7.3)

General Histology

2

Fig. 7.3: White fibrocartilage

A. The cartilage cells are relatively sparse. B. They occur as single cells, groups and rows. C. Visible matrix is limited to the near vicinity of cartilage cells. D. Coarse collagenous fibres are predominant. E. These fibre-bundles usually take a common direction. 5. Regenerative ability A. Injuries are not repaired by the cartilage tissue itself. This is because adult cells are imprisoned in matrix and probably never divide. B. Tissue from the perichondrium and adjacent fascia proliferates and fills in the defect or gap. C. A fracture of a mature cartilage usually becomes united by dense fibrous tissue. 6. Histology A. Cells a. Large cells (singly, in groups or in rows). b. Single cells are rounded when deeply located. c. The cells are flattened near surface. d. The cartilage cells are shrunken and vacuolate, owing to loss of water and fat. B. Matrix: a. It is abundant and basophilic. It stains more deeply in the vicinity of cells. b. The ground substance is largely replaced by collagen fibres. c. Ordinary matrix is seen only near vicinity of cells.

Cartilage

SN-12

57

Draw and write a note on elastic cartilage

1. Features A. It is highly flexible. B. It is resistant to degeneration. C. It has limited capacity of regeneration. D. The elastic fibres are profuse. E. They vary in thickness and quantity in various cartilages. F. Perichondrium is present. It consists of a. Outer fibrous, and an b. Inner chondrogenic and vascular layer. 2. Histology

Fig. 7.4: Elastic cartilage

B. Chondrocytes a. Like hyaline cartilage, it contains typical chondrocytes. b. They are either singly or in small groups. c. They are surrounded by a matrix. The matrix in type II collagen fibrils. C. Matrix a. It is occupied by very fine yellow elastic fibres. b. It contains the protein elastin. It does not show periodic banding under the electron microscope. Examples External ear External acoustic meatus (lateral part)

2 General Histology

A. Elastic fibres a. In H and E stain, they are eosinophilic. b. Elastic fibres are visualised by special staining methods (Orcein stain). c. They appear black with Verhoeff-Van Gieson stain. d. They are heavily concentrated in the centre of cartilage than near perichondrium. e. It has numerous branches (Fig. 7.4).

Exam-Oriented Anatomy

58

Eustachian tube (medial part) Epiglottis Corniculate cartilage  Cuneiform cartilage  small cartilages present in aryepiglottic fold Box 7.3 It is interesting to note the examples of elastic cartilage a. It is found at sites, where support is required along with flexibility. b. Most sites in which elastic cartilage occur have vibrational functions, such as I. Laryngeal sound wave production, or the II. Collection and transmission of sound waves in the ear. The examples of the elastic cartilage begin with the first and last letter of the word “ElastiC”

General Histology

2

3. Applied anatomy : The traumatic distorted injury of external ear gets repaired by

a cauliflower ear, as seen in participants of some contact sports (wrestlers).

8 Bone

OLA-6

What are Howship’s lacunae?

1. There are shallow pits present on the resorbed surfaces of bone. These pits are called Howship’s lacunae. They are occupied by osteoclasts. 2. Lysosomal enzymes released by osteoclasts erode these depressions. 3. The part of the cell facing the lacunae is thrown into finger-like processes which interdigitate with similar reciprocal processes in the bone. This end of the cell is called a ruffled membrane. They are filled with vacuoles. The area surrounding the membrane, close to the bone is called the colour zone. The cells are rich in lysosomes and contain bone debris. They arise from the mononuclear cells of the bone marrow. OLA-7

What is osteon? Or Haversian system?

Osteon • It consists of the central Haversian canal which conduct vessels, lymphatics and nerves. • It is present only in compact bone. • There are 18–50 concentric lamellae. • The spaces between lamellae are called lacunae. They contain osteocytes. • Canaliculi: These are fine channels containing cytoplasmic processes of osteocytes. OLA-8

State the different types of lamellae in the bone

There are three types of lamellae. 1. Concentric lamellae are present around the Haversian canal. 2. Interstitial lamellae are present between two Haversian systems. They do not belong to any Haversian system. 3. Circumferential lamellae: These are of two types. A. Outer circumferential around bone. B. Inner circumferential. 59

Exam-Oriented Anatomy

60

OLA-9

What is Volkmann’s canal?

It connects Haversian system to periosteum. It pierces lamellae and runs transversely. OLA-10 State the cells of bone. Describe each briefly.

General Histology

2

1. Structure A. Following cells are present. a. Osteogenic cells I. They are precursors of osteoblasts. II. They are present in cellular layer of periosteum. Note: According to Hindu mythology, there are three Gods. They are Brahma, Vishnu and Mahesh. The God Brahma is creator of the world, Vishnu is preservor and Mahesh is destroyer. The simile can be used to understand the functions of bone cells. Osteoblast is creator of bone, osteocyte is preserver and osteoclast is destroyer of bone. b. Osteoblasts (Fig. 8.1) I. They are active, large and basophilic cells. They are present during bone formation. II. The nucleus is round and eccentric. c. Osteocytes (Fig. 8.2) I. Present in lacuna of fully formed bone. II. They have cytoplasmic processes. d. Osteoclasts: They are (Fig. 8.3) I. Bone modelling cells.

Fig. 8.1: Osteoblast

Fig. 8.2: Osteocytes

Fig. 8.3: Osteoclast

Bone

61

II. Formed by giant cells. III. Multinucleated and eosinophilic. OLA-11 What is osteoclast?

Osteoclasts are 1. Bone modelling cells. 2. Formed by giant cells. 3. Multinucleated and eosinophilic. SN-13

Compact Bone

Introduction: It is a specialized connective tissue with mineralized matrix.

b. Osteoblasts • They are active, large and basophilic cells. They are present during bone formation. • The nucleus is round and eccentric. c. Osteocytes • Present in fully formed bone in lacunae. • They have cytoplasmic processes. d. Osteoclasts are • Bone modelling cells. • Formed by giant cells. • Multinucleated and eosinophilic. 2. Matrix: Following elements are present in matrix. A. Organic elements a. Dense bundle of collagen fibres, b. Ground substance, c. Hyaluronic acid, and d. Protein polysaccharides. B. Inorganic elements a. Calcium phosphate (Ca3(PO4)2) b. Calcium carbonate (CaCO3) c. Calcium chloride (CaCl2) and d. Magnesium chloride (MgCl2)

2 General Histology

1. Structure (Fig. 8.4) A. Following cells are present. a. Osteogenic cells are • Precursors of osteoblasts. • Present in cellular layer of periosteum.

62

General Histology

2

Exam-Oriented Anatomy

Fig. 8.4: Compact bone TS

3. Osteon (Haversian system) A. Types a. Primary osteon represents the initial structural unit of compact bone. It is formed by deposition of successive lamellae of bone. They are deposited on the walls of vascular channels. b. Secondary osteon: As the diaphysis increases in girth, all the original woven bone and primary osteon bone are removed by endosteal erosion. It undergoes a change in character. It results in development of new tracts of bone. This is called secondary osteon. B. Features a. It consists of the central Haversian canal which conduct vessels, lymphatics and nerves. b. Nerve is present only in compact bone. c. There are 18–50 concentric lamellae. d. The spaces between lamellae are called lacunae. They contain osteocytes. e. Canaliculi: These are fine channels containing cytoplasmic processes of osteocytes. 4. Lamellae: There are three types of lamellae. A. Concentric lamellae are present around the Haversian canal. B. Interstitial lamellae are present between two Haversian systems. They do not belong to any Haversian system. C. Circumferential lamellae: These are of two types. a. Outer circumferential lamellae are present around bone. b. Inner circumferential. 5. Periosteum: It has two layers A. Outer: Fibrous which contains collagen fibres. B. Inner: Cellular layer contains osteocytes.

Bone

63

6. Sharpe’s fibres enter from periosteum to outer circumferential lamellae. 7. Volkmann’s canal: It pierces lamellae and connects Haversian system to periosteum. It runs transversely. 8. Site A. Shaft of long bone. B. Outer layer of all compact bones. 9. Blood supply of compact bone is by nutrient artery. Osteocytes get nutrition from nutrient artery.

General Histology

2

9 Muscle

OLA-12 Classify muscles with examples

1. Muscles are classified as: A. Functionally, and B. Structurally. A. Functionally it is either a. Voluntary muscles: They are under control of will, e.g. all skeletal muscles. b. Involuntary muscles: These are not under control of will, e.g. all smooth muscles. B. Structurally it is either a. Striated (cross-striped)—shows serial banding of fibres, e.g. all skeletal muscles. b. Smooth (unstriped)—shows no banding of fibres, e.g. all smooth muscles. 2. The two classifications can be combined as follows A. Smooth involuntary muscle: It is smooth muscle, mostly present in hollow organs. B. Striated involuntary muscle: It is cardiac muscle of the heart wall. C. Striated voluntary muscle: It is skeletal muscle, attached to the various bones. OLA-13 Describe transverse section (TS) of skeletal muscle

TS of skeletal muscle 1. It is multinucleated. 2. The nuclei are situated peripherally and immediately below the sarcolemma of each muscle fibre. 3. The sarcolemma is not visible in TS. 4. Each skeletal muscle fibre shows cross-striations. 5. They are visible as alternating dark A bands and light I band. 6. With higher magnification and transmission electron microscopy, additional details of the cross-striations are visible. 7. Skeletal muscle fibres are aggregated into bundles or fascicles. 8. They are surrounded by fibres of connective tissue. 64

Muscle

65

9. The connective tissue sheath around each muscle fascicle is called the perimysium. 10. From each perimysium, thin partitions of connective tissue extend into each muscle fascicle. 11. These partitions invest individual muscle fibres with a connective tissue layer called the endomysium. 12. Small blood vessels and capillaries are present in the connective tissue around each muscle fibre. OLA-14 Describe longitudinal section (LS) of skeletal muscle

LS of skeletal muscle It shows light and dark cross-striations. The muscle fibres that were sectioned transversely show cross-striations of myofibrils and peripheral nuclei.

Intercalated discs 1. Features A. They are characteristic features of cardiac muscles. B. These are densely stained. C. They have special attachment sites that cross the cardiac cells in a stepwise fashion at irregular intervals. D. They represent the specialized junctional complexes between cardiac muscle fibres. E. The intercalated discs appear as either straight bands or staggered across individual fibres (Fig. 9.1).

Fig. 9.1: Cardiac muscle

2 General Histology

OLA-15 What is intercalated disc? What are its functions?

Exam-Oriented Anatomy

66

2. Functions A. They connect individual cardiac muscle fibres. B. They allow a rapid spread of stimuli throughout the entire muscle mass. C. Conduction of excitatory impulses to the cardiac sarcomeres is through the a. T tubules, and b. Sarcoplasmic reticulum. D. There are ions present in the gap junctions. They are diffused through the pores. The diffusion of ions coordinates heart function. E. They allow the cardiac muscle to act as a functional syncytium. F. They allow the stimuli for contraction to pass through the entire cardiac muscle. OLA-16 Difference between smooth, cardiac and skeletal muscles

General Histology

2

Table 9.1: Difference between smooth, cardiac and skeletal muscles Sections

Features

Smooth muscle

Cardiac muscle

Skeletal muscle

• Longitudinal section

• Bundles

• Relatively small bundles

• Coarsely branching

• Very large solitary band

• Striation

• No

• Weakly striated • Strongly striated

• Nuclei

• Nuclei—slender and more elongated

• Thick and short

• Thick and short

• Fibres

• Much smaller

• Bigger

• Biggest

• Size

• Variation wide

• Moderate variation

• Fair uniformity in given muscle

• Myofibril

• Absent

• Present

• Present

• Nuclei

• Central

• Central

• Size of nuclei

• Largest

• Transverse section

• Enclosed in • Tightly packed connective tissue

• Peripheral • Smallest

• Endomysium

• Endomysium

OLA-17 Cardiac muscle

Refer to Fig. 9.1 1. It is a striated and involuntary muscle. 2. Fibres: Each fibre of the muscle is called myocyte. It branches and anastomoses to form syncytium. 3. Nucleus: Each myocyte contains one nucleus which is placed centrally. 4. Length of myocyte: 50 μm. 5. Width of myocyte: 18 μm.

Muscle

67

6. Sarcoplasm: Contains mitochondria. 7. Striations: Not very prominent, as a few myofibrils are present. 8. Peculiarity: It contains a large amount of glycogen, myoglobin and is rich in capillary network. 9. Intercalated disc: It is junction between myocyte. It appears dark-stained transverse lines. It lies opposite the ‘I’ band. It has two parts. A. Transverse portion B. Lateral portion Due to transverse and lateral portions, intercalated disc appears stepwise. 10. Gap junction: Cell membrane and adjacent myocytes are connected by desmosome and is called gap junction. Sarcomere

Introduction: It is the segment of myofibril between two ‘Z’ discs. 1. Features A. A sarcomere is segment of the fibre between successive Z bands. B. It is the smallest structural and functional contractile unit of the muscle. C. It is the repeating contractile units seen along the entire length of each myofibril. D. It is highly characteristic feature of the sarcoplasm of skeletal and cardiac muscle fibres. E. It is about 2.5 μm long. F. It contains a. A band, and the b. 1/2 of “I” band. G. Mild trypsin digestion destroys the Z lines. The fibre then fractures into sarcomere segments. H. Myofibril is the finer structural and functional unit of the sarcomere (Fig. 9.2).

Fig. 9.2: Sarcomere

2 General Histology

SN-14

68

General Histology

2

Exam-Oriented Anatomy

2. Each myofibril A. Diameter: 1–2 μ B. Length: As long as muscle fibre. C. Character: Light and dark zone under light microscope, causes difference in the refractive index. D. Filaments a. Actin, and b. Myosin. 3. Dark zone: Anisotropic (A band). H band is clear area in A band. M line is thickened central part of H band. 4. Light zone: Isotropic (I band). The centre of the light zone is called Z disc (Krause’s membrane). 5. Sarcomere: ½ of I + A + ½ of I 6. During contraction: Actin filaments slide between myosin filaments. They slide towards the centre of sarcomere. Z discs are brought closer and shorten the contractile unit. A band remains the same.

10 Blood Vessels

SN-15

Draw and describe muscular artery

1. Synonymous: It is the medium size artery (distributing artery). 2. Layers: It consists of three layers A. Tunica intima a. It shows folded appearance. b. The internal elastic lamina is prominent and wavy. B. Tunica media: It shows plenty of smooth muscle cells, arranged concentrically. C. Tunica adventitia a. It is as thick as media. b. The diameter of the lumina is less than thickness of wall (Fig. 10.1A and B).

Fig. 10.1A: Muscular artery 69

Exam-Oriented Anatomy

70

Fig. 10.1B: Muscular artery

General Histology

2

3. Functions: It regulates the flow of the blood in different regions. 4. Examples: Most of the arteries of body distal to subclavian artery. A. Branches of common carotid, B. Thoracic, and C. Abdominal aorta. SN-16

Draw and describe elastic artery

1. Synonymous: It is a large size artery called elastic artery (Fig. 10.2A and B). 2. Layers: It consists of three layers A. Tunica intima a. It is innermost coat and lined by simple squamous epithelium. b. It contains elastic fibres. c. The subendothelial layer is prominent and contains elastic fibres d. The internal elastic lamina is present but indistinguishable. B. Tunica media a. It is a middle and thickest coat.

Fig. 10.2A: Elastic artery

Blood Vessels

71

Fig. 10.2B: Elastic artery

b. It consists of concentric layer of fenestrated elastic fibres. c. It also contains a little amount of smooth muscle and collagen fibres. C. Tunica adventitia a. It is thin and contains elastic fibres.

SN-17

Draw and describe vein

1. Histology A. It exhibits three layers or tunica. a. The tunica intima shows endothelium and subendothelial connective tissue. b. The muscular layer is much thinner and less prominent. The smooth muscles intermix with connective tissue fibres. c. The tunica adventitia is the thickest and best-developed layer of the three layers. B. Features a. Wall I. It is thin as compared to arteries of similar size. II. Thickness is not correlated exactly with the size of the vein and varies in different regions. For example, wall is thicker in veins of the leg than it is in veins of a similar size in the arm. b. Muscle I. Amount of muscle is considerably less than in arteries. II. The collagen and elastic fibres predominate. III. In most veins of the limbs, the muscles are arranged circularly. IV. Longitudinal muscles are present in the following veins i. Iliac, ii. Brachiocephalic, iii. Portal, iv. Renal, v. Superior, and vi. Inferior venae cavae.

2 General Histology

b. The fibres merge with external elastic lamina. 3. Lumina: It is irregular. The diameter of the lumina is more than the thickness of wall. 4. Functions: It conducts blood from heart to the different parts of body. 5. Examples: Aorta, large arteries of head and neck.

72

General Histology

2

Exam-Oriented Anatomy

V. Muscles are absent in i. Maternal placental veins, ii. Dural venous sinuses, iii. Pial and retinal veins, iv. Veins of trabecular bone, and v. Venous spaces of erectile tissue; These veins consist of endothelium supported by variable amounts of connective tissue. VI. Distinction between the media and adventitial layers is often difficult. VII. Discrete internal elastic lamina is absent. VIII. Collapse of the veins is prevented i. Connective tissue fasciae, and ii. Surrounding tissues. IX. Valves i. Veins have valves which convey blood against gravity. ii. They assist venous blood flow toward the heart by preventing backflow. iii. When blood flows toward the heart, pressure in the veins forces the valves to open. iv. As the blood begins to flow backward, the valve flaps close the lumen. Thus, it prevents backflow of blood. v. They are found in small veins and at the junctions of tributaries. (cusps) and attached by their convex edges vi. The valves are semilunar to the venous wall. vii. Valves are absent in the veins of the thorax and abdomen. C. Classification of veins: The veins are arbitrarily classified as a. Small, b. Medium, and c. Large. D. Functions a. The structure of the venous walls allows I. Flexibility, and II. Accommodation of a large amount of blood. As a result, veins contain most of the blood present in the body. b. Pressure within the venous system does not normally exceed 5 mm Hg. c. Pressure decreases as the veins grow larger. d. It maintains cardiac output by effectively mobilizing the blood. e. A sudden fall in blood volume (e.g. following a haemorrhage) is compensated by I. Elastic recoil of the vein, and II. Reflex constriction of vein.

Blood Vessels

73

The differences between arteries and veins are tabulated in Table 10.1. Table 10.1: The differences between arteries and veins Particular

Arteries

Veins

1.

Lumen

Patent, RBC not seen

Lumen may be collapsed RBC usually seen

2.

Endothelial lining

Well defined

Not so well defined

3.

Internal elastic lamina

Distinct

Poorly defined

4.

Tunica media

Forms 2/3rd of the thickness of the wall

Forms 1/3rd of the thickness of the wall

5.

External elastic lamina

Distinct

Not well defined

6.

Tunica adventitia

Forms 1/3rd of the thickness of the wall

Forms 2/3rd of the thickness of the wall

7.

Extent of vasa vasorum

Supply extends up to outer 2/3rd of tunica media

Supply extends up to tunica intima

2 General Histology

No.

Fig. 10.3A: Fingers of the right hand showing difference between arteries

Fig. 10.3B: Fingers of the right hand showing difference between veins

Fingers of right hand

Coats of artery

Coats of veins

Index

Tunica adventitia

–

Middle

Tunica media

Tunica adventitia

Ring

Tunica intima

Tunica media

Little finger

–

Tunica intima

11 Lymphoid Tissue

OLA-18 Draw and describe any of the following: Spleen, lymph node, tonsil, thymus

Lymph node

Fig. 11.1: Lymph node

Introduction: It is a member of lymphatic system. It consists of rounded follicles of lymphocytes. They are more in the periphery (cortex). 1. Types: There are two types of lymphocytes. A. B lymphocytes are found in the follicles and medulla. B. T lymphocytes are found in the paracortical areas and in the cortex between follicles. 74

Lymphoid Tissue

75

2. Characters A. Covered by dense connective tissue called capsule which contains smooth muscle cells. B. Afferent lymphatics enter into the subscapular space. C. Consists of outer cortex and inner medulla. a. Cortex is packed with lymphocytes. b. Number of rounded lymphatic follicles is present. c. Each nodule has a pale staining germinal centre surrounded by densely packed lymphocytes. d. Within the medulla, the lymphocytes are arranged in the form of anastomosing cords Loose areolar tissue

Introduction: It is connective tissue made up of bundles of fibres which encloses large spaces called areola (Fig. 11.2). 1. Structure A. Made up of bundle of fibres. Table 11.1: Different types of fibres and their details Particulars

Collagen

Reticular

Elastic

• Synonyms • Gross • External – Arrangement – Diameter – Nature

• White

• Argyrophilic

• Yellow

• Runs in bundle • 7–12 μm • Straight, wavy

• Runs in single – • Thin

• Bundles branch, individual fibres do not branch • Present • Tropocollagen

• Present

• Runs in single • Fine, straight, • Highly refractile, spiraling

• Absent • Reticulin

• Present • Elastin protein

– Branching – Anastomosis – Composition • Characters – Elasticity – Toughness – Flexibility • Action on – Boiling – Acid

• No • Yes • Yes

• No • No • Yes

• Yes • Yes • Yes

• Forms gelatin –

– • No

– • Resistant

• Stained with

• H and E

• Silver staining

• Orcein

• Example

• • • •

• Spleen, • Lymph node, and • Bone narrow

• Walls of blood vessel, • Vocal cords, and • Ligamentum flava

Tendons, Ligament, Capsule, and Dermis of the skin

2 General Histology

SAQ-2

Exam-Oriented Anatomy

76

General Histology

2 Fig. 11.2: Loose areolar connective tissue

B. Cells a. Fibroblast, b. Macrophages, c. Mast cells, d. Lymphocytes, e. Fat cells, f. Pigment cells and g. Plasma cells. 2. Abundant intercellular space. 3. Site A. Superficial fascia B. Ligamenta flava C. Basement membrane.

3 Lower Limb • Bones of Lower Limb • Front of Thigh • Medial Side of Thigh • Gluteal Region • Popliteal Fossa • Back of Thigh • Front, Lateral and Medial Sides of Leg and Dorsum of Foot • Back of Leg • Sole of Foot • Venous and Lymphatic Drainage and Comparison of Lower and Upper Limbs • Joints of Lower Limb • Arches of Foot

Attention Please All the texts in box are not to be written in the examination. Muscles are represented as original shapes in the body. These are for the memorization of the muscles. Students are not required to draw such shapes in the examination.

Name of muscles

1. Abductor digiti minimi 2. Abductor hallucis 3. Abductor brevis 4. Abductor hallucis 5. Abductor longus 6. Abductor magnus 7. Biceps femoris 8. Dorsal interossei 9. Erector spinae 10. Extensor digitorum brevis 11. Extensor digitorum longus 12. Extensor hallucis longus 13. Flexor digiti minimi brevis 14. Flexor digitorum accessorius 15. Flexor digitorum brevis 16. Flexor digitorum longus 17. Flexor hallucis brevis 18. Flexor hallucis longus 19. Gastrocnemius 20. Gluteus maximus 21. Gluteus medius 22. Gluteus minimus 23. Gracilis 24. Iliacus 25. Latissimus dorsi 26. Obturator extemus

Shape

I

'f

f

t

, ,u

I

1

� I

II\

{

'

I

'' I ' �

/

__,

Name of muscles

27. Obturator intemus 28. Pectineus 29. Peroneus brevis 30. Peroneus longus 31. Peroneus tertius 32. Piriformis muscle 33. Plantaris 34. Plantar interossei 35. Popliteus 36. Psoas major 37. Quadratus femoris 38. Rectus femoris 39. Sartorius 40. Semimembranosus 41. Semitendinosus 42. Soleus 43. Tensor fascia latae 44. Tibialis anterior 45. Tibialis posterior 46. Vastus intermedius 47. Vastus lateralis 48. Vastus medialis

Shape

f /

l

t

,

r

�

,�

,.. '

.,I

)

f

�

f

)

\

\

\

t

\

Bones of Lower Limb

OLA-1

12

Attachments to intertrochanteric line

The intertrochanteric line provides 1. Attachment to the following ligaments A. Capsular ligament of the hip joint, B. Upper band of the iliofemoral ligament in its upper part, and C. Lower band of iliofemoral ligament in its lower part. 2. Origin to the highest fibres of the following muscles. A. Vastus lateralis from the upper end of the line, and B. Vastus medialis from the lower end of the line. OLA-2

Enumerate the structures attached to pubic tubercle

1. Ligament A. Apex of lacunar ligament B. Medial end of inguinal ligament C. Reflected part of inguinal ligament 2. Fascia A. Superficial layer of fascia lata, B. Fascia transversalis. 3. Muscle: Ascending loops of cremaster muscle in male, and 4. Superior crus of saphenous opening. SN-1

Fig. 12.1: Attachments of pubic tubercle

Greater sciatic notch

1. The posterior border of ilium of hip bone is divided by ischial spine into two notches A. Greater sciatic notch—above the spine, and B. Lesser sciatic notch—below the spine. 79

Exam-Oriented Anatomy

80

2. The structures passing through greater sciatic notch are divided by the piriformis into (Fig. 12.2) A. Structures above piriformis, a. Superior gluteal vessels—branch/tributary of posterior division of internal iliac artery, and b. Superior gluteal nerve L4, L5, S1. B. Structures below piriformis (from medial to lateral): They are divided into three groups a. Structures going to gluteal region I. Laterally i. Sciatic nerve (L4, L5, S1, S2, S3). It lies at the inferior margin of greater sciatic notch, ii. Nerve to quadratus femoris (L4, L5, S1). II. Medially: Nerve to obturator internus (L5, S1, S2). It crosses the base of the ischial spine. III. Intermediate position: Inferior gluteal vessels and nerve (L5, S1, S2). b. Structures which re-enter into lesser sciatic notch I. Internal pudendal vessels of smaller terminal branch/tributary of posterior division of internal iliac vessels, and II. Pudendal nerve (S2, S3, S4). It lies close to the tip of ischial spine.

Lower Limb

3

C. Structures going to thigh region: Posterior femoral cutaneous nerve of thigh.

Fig. 12.2A: Structures passing through the right greater sciatic notch

Fig. 12.2B: Right hip bone seen from behind showing greater sciatic foramen

Bones of Lower Limb

81

3. Applied anatomy

 About greater sciatic notch:  At the upper border of greater sciatic notch, the internal iliac artery divides into anterior and posterior divisions.  Internal iliac vein begins above greater notch.  There is a preauricular sulcus above it. It is deep in female hip bone and more pronounced in the hip bones of multiparous female.  It is converted into greater sciatic foramen by sacrospinous ligament.  Anterior gluteal line starts from middle of upper margin of greater sciatic notch.  About lesser sciatic notch:  Pudendal canal extends from lesser sciatic notch to deep perineal pouch.  It is converted into lesser sciatic foramen by sacrotuberous ligament.  The inferior gemellus muscle arises from inferior margin of lesser sciatic notch near ischial tuberosity. SAQ-1

Organs related to hip bone Table 12.1: Organs related to the hip bone Organs Male

Female

• Pelvic part of pubic bone

• Urinary bladder • Prostate gland

• Urinary bladder

• Anterior margin of greater sciatic notch

• Ureter

• Ovary and ureter

• Transtubercular plane

• Appendix and caecum on right side of pelvis.

• Pubic tubercle

• Spermatic cord

SN-2

• Round ligament of uterus

Linea aspera

(Linea—line, aspera—thick, broad, thickened ridge) 1. Definition: It is irregular thick line present on the posterior border of femur. 2. Features A. In middle 1/3rd of thigh, it forms the apex of adductor canal. B. It gives attachment to intermuscular septa. These septa divide muscles of thigh into extensor, adductor and flexor compartments. Following are the muscles attached to linea aspera (from lateral to medial) (Fig. 12.3). I Love B. Mr. B Loves Me Vastus Intermedius, Vastus Lateralis,

3 Lower Limb

Bone

82

Exam-Oriented Anatomy

Short head of Biceps femoris Adductor Magnus, Adductor Brevis, Adductor Longus, and Vastus Medialis.

Lower Limb

3

Fig. 12.3A to C: Muscles attached to linea aspera of right femur (from medial to lateral)

3. Fate of linea aspera A. It divides into medial and lateral lips at both the ends. B. Fate of these lips a. At upper end. I. The medial lip continues with the spiral line, and II. The lateral lip continues to the gluteal tuberosity. b. At lower end I. Medial lip continues as medial supracondylar line, and II. Lateral lip continues as lateral supracondylar line.

Bones of Lower Limb

83

4. Applied anatomy

 It acts as a buttress to resist the compressive forces. Hence, it prevents the anterior bowing of the shaft.  The nutrient foramen of the femur lies on the linea aspera. It is directed upward.  The perforating branches of profunda femoris are closely related to the linea aspera. SAQ-2

Adductor tubercle

Introduction: It is the 1st bony prominence felt on the medial side of thigh as you slide your finger from above downwards. 1. Gives attachment to A. Ischial fibres of adductor magnus muscle, and B. Tibial collateral ligament. 2. Applied anatomy

SN-3

Iliac crest

Introduction: It is an ‘S’-shaped curvature present on the upper border of ilium (Fig. 12.4). 1. Curvatures A. Vertical curvature: It is convex upwards. B. Anteroposterior a. It is concave inwards in front, and b. Concave outwards behind. 2. It shows two spines at both the ends. A. Spines a. Anterior superior iliac spine gives attachment to I. Inguinal ligament, and II. Sartorius. b. Posterior superior iliac spine gives attachment to piriformis. B. Iliac crest has a. Ventral segment which is subdivided into I. Anterior 2/3rd: It gives attachment to following muscles (from lateral to medial).

3 Lower Limb

 It forms a bony landmark for surface anatomy.  The epiphyseal line in the femur runs transversely through the adductor tubercle.  Damage of adductor tubercle during surgical intervention. leads permanent shortening of the lower limb. This is applicable to the bone before ossification.  To palpate the tubercle, flex the knee partly and note the wide, shallow groove that appears posterior to the mass of vastus medialis. The tendon of adductor magnus can be felt in this groove. It can be traced down to the adductor tubercle.

84

Exam-Oriented Anatomy

i. Fascia lata in whole extent, ii. Tensor fasciae latae in front of tubercle, iii. External oblique, iv. Internal oblique, v. Transversus abdominis, and vi. Fascia transversalis. II. Posterior 1/3rd: It gives attachment to following muscles (from lateral to medial) i. Latissimus dorsi, ii. Quadratus lumborum (L for L—Latissimus for Lateral), and iii. Thoracolumbar fascia around quadratus lumborum. b. Dorsal segment gives attachment to I. Gluteus maximus in outer sloping area, and II. Erector spinae in inner sloping area.

Lower Limb

3 Fig. 12.4: Structures attached to right iliac crest

3. Ends: It has two ends. A. Anterior end is called anterior superior iliac spine, and B. Posterior end is called posterior superior iliac spine. 4. Bony landmarks A. The highest point of the iliac crest is situated a little behind the midpoint of the crest. B. It lies at the level of the interval between the spines of vertebrae L3 and L4. 5. Surface anatomy A. Iliac crest can be felt in the living at the lower limit of the flank. B. Anterior superior iliac spine (ASIS) is a prominent landmark. It is easily felt in the living individuals.

Bones of Lower Limb

85

6. Applied anatomy

 Anterior superior iliac spine is important surface landmark especially used by tailors for taking measurements.  Iliac crest is used for bone grafting.  Iliac crest is used for bone marrow examination.  Tuberosity of iliac crest is subcutaneous bone which can be palpated in fatty patient. It helps to find out highest point of iliac crest and anterior superior iliac spine. SAQ-3

Structures attached to spines of hip bone Table 12.2: Structures attached to spines of hip bone Attachments Muscles

Ligaments

• Anterior superior iliac spine

• Sartorius in lower part

• Lateral end of inguinal ligament in upper part

• Anterior inferior iliac spine

• Straight head of rectus femoris in upper part

• Iliofemoral ligament in lower part

• Posterior superior iliac spine

• Erector spinae

• Posterior sacroiliac ligament and sacrotuberous ligament

• Posterior inferior iliac spine

• Piriformis

• Sacrotuberous ligament

• Ischial spine

• Posterior fibres of levator ani

• Sacrospinous and coccygeal ligaments.

SAQ-4

Trochanteric anastomosis

Site: Trochanteric fossa 1. Arteries taking part A. Ascending branch of medial B. Ascending branch of lateral

  

circumflex femoral artery branch of profunda femoris artery

C. Branches of internal iliac artery a. Descending branch of superior gluteal artery. b. Inferior gluteal artery, c. Internal pudendal artery (Fig. 12.5) 2. Applied Anatomy

 It provides chief source of blood supply to the  Head of femur, and  Intracapsular part of neck of femur.

3 Lower Limb

Spines

86

Exam-Oriented Anatomy

Fig. 12.5: Arteries forming right trochanteric anastomosis

 Trochanteric anastomosis is between branches of internal iliac and femoral arteries. In case of blockage of one of the arteries, the collateral circulation is developed to maintain the blood supply to this region.

Lower Limb

3

13 Front of Thigh

OLA-3

1. 2. 3. 4.

Name the muscles forming boundaries of femoral triangle

Lateral boundary is formed by medial border of sartorius. Medial boundary is formed by medial border of adductor longus. Base is formed by inguinal ligament. Apex is formed by the meeting point of the medial borders of adductor longus and sartorius.

OLA-4

Name the muscles forming the floor of femoral triangle

The muscles forming floor of femoral

(from medial to lateral) are

1. Medial sloping wall is formed by A. Adductor longus medially, and B. Pectineus laterally. 2. Lateral sloping wall is formed by A. Psoas major medially, and B. Iliacus laterally. OLA-5

1. 2. 3. 4.

Name the structures forming the boundaries of femoral ring

Anteriorly: Inguinal ligament, Posteriorly: Pectineus and fascia covering it, Medially: Concave margin of lacunar ligament, and Laterally: Septum separating it from femoral vein.

OLA-6

Name the cutaneous nerves seen in roof of femoral triangle

1. Femoral branch of the genitofemoral nerve (L1, L2)—it supplies the skin over the upper part of femoral triangle. 2. Branches of ilioinguinal nerve. 87

Exam-Oriented Anatomy

88

3. Medial cutaneous nerve of thigh—it crosses the femoral artery from the lateral to medial. 4. Lateral cutaneous nerve of thigh is seen lateral of femoral triangle.

Fig. 13.1: Cutaneous nerves seen in roof of right femoral triangle

OLA-7

Lower Limb

3

Name the muscles of anterior compartment of thigh

The muscles of the anterior compartment of the thigh are 1. Sartorius, 2. Quadriceps femoris which includes A. B. C. D.

Rectus femoris, Vastus lateralis, Vastus medialis, and Vastus interemedius.

3. Articularis genu. SN-4

Superficial inguinal lymph nodes

Introduction: The lymph vessels draining all the structures superficial to deep fascia of lower limb drain into superficial inguinal lymph nodes. They accompany the great saphenous vein. 1. Arrangement: They are arranged in the form of a “T”. 2. Location A. Along the great saphenous vein is the vertical group of inguinal lymph nodes, and B. Parallel to inguinal ligament is the horizontal group of lymph nodes. 3. Afferent and efferent lymphatics (Table 13.1)

Front of Thigh

89

Fig. 13.2: Superficial inguinal lymph nodes of right leg Table 13.1: Various groups of superficial inguinal lymph nodes and their afferent and efferent lymphatics Efferent

Site

Afferent

• Lower vertical

• Along great saphenous vein

• It receives lymphatics from all the structures superficial to deep fascia of lower limb except buttock and popliteal nodes.

• Upper lateral group

• Along lateral part of inguinal ligament

• Lateral part of anterior abdominal wall below the umbilicus.

• Upper medial group

• Medial end of • Medial part of anterior abdo• Drains into minal wall below the umbilicus. deep inguinguinal ligament • One or two lymph • Perineum including external inal lymph nodes above the genitalia except glans penis in nodes, inguinal ligament which lie and clitoris in female . male along the superalong upper • Part of the anal canal below the ficial epigastric part of fempectinate line. oral vessels. vessels. • In female —vagina below the • Few directly hymen. to external • In male —only skin of penis iliac nodes and glans. • Superolateral angle of the uterus.

4. Applied anatomy

 The upper group of the superficial inguinal lymph nodes are enlarged due to pathology of the following structures. It may be infection or malignant growth of one of the following structures.  Superolateral part of uterus,  Skin of shaft of penis,  Part of vagina below the hymen, and  Part of the anal canal below the pectinate line.  Syphilitic lesion of prepuce of penis.

3 Lower Limb

Lymph node

Exam-Oriented Anatomy

90

 Lateral group lymph nodes of superficial inguinal lymph nodes are enlarged due to pathology of the gluteal region. SN-5

Fascia lata

(Lata—deep and broad) Introduction: It is a tough, fibrous, deep fascia which envelops the thigh like a stocking. 1. Modifications A. Iliotibial tract, and B. Saphenous opening. 2. Gives attachments (Fig. 13.3A and B) A. Proximally is attached to a. Pubic tubercle, b. Inguinal ligament, c. Outer lip of entire iliac crest (it splits to enclose the tensor fascia lata and gluteus maximus muscles), d. Dorsal surface of sacrum, e. Coccyx, f. Sacrotuberous ligament, and g. Ischial tuberosity.

Lower Limb

3

B. Anteromedially attached to a. Ischiopubic ramus, b. Anterior margin of pubic symphysis, c. Pubic crest, d. Pubic tubercle, and e. Pectin pubis. C. Distally attached to the a. Patella, b. Inferior margin of the tibial condyles, and c. Head of the fibula. 3. Encloses A. Gluteus maximus B. Tensor fascia lata. 4. Functions A. Protects the deeper structures, B. Keeps deeper structures in position, and C. It acts as tight stockings and helps in venous return.

Front of Thigh

91

Fig. 13.3A: Extent and attachments of right fascia lata Fig. 13.3B: Fascia lata in the form of “8”

Iliotibial tract

It is a modified thick fascia of thigh (fascia lata). It is a 2” wide band. 1. Situation: It is present on lateral aspect of thigh. Extends from iliac crest to lateral condyle of tibia. A. Superiorly it has two laminae. a. Superficial lamina is attached to tubercle of iliac crest, and b. Deep lamina is attached to capsule of hip joint. B. Inferiorly it is attached to smooth area on the anterior surface of lateral condyle of the tibia. 2. Features: It gives insertion to (Fig. 13.4). A. Greater part of gluteus maximus, B. Tensor fascia lata. 3. Nerve supply : Superior gluteal nerve (L4, L5).

4. Functions A. It stabilizes the knee joint both in extension and partial flexion. Hence, it is used constantly during walking and running. B. It is the main support of knee joint against gravity. C. It is used as suturing material. SN-7

Saphenous opening

(Saphenous—easily seen) Introduction: It is an oval

opening present in the fascia lata.

3 Lower Limb

SN-6

92

Exam-Oriented Anatomy

Fig. 13.4: Posterior view of right hip bone showing attachments of iliotibial tract

Lower Limb

3

1. Location: 4 cm below and 4 cm lateral to pubic tubercle. The vertical height is 4 cm. It has two margins A. Upper, lateral and lower, and B. Medial margin. A. The lateral margin is superficial and well defined. a. It is half-moon shaped , and b. It is present in front of femoral sheath. It is also called falciform margin. B. Medial margin is deep and ill defined due to cribriform fascia. 2. Opening: It is closed by areolar membrane called cribriform fascia. The fascia is pierced by number of structures and gives a sieve-like appearance, hence it is called cribriform fascia (Figs 13.5 and 13.6). 3. The structures passing through saphenous opening are the following A. Vein: Great saphenous vein. It receives following veins before it opens in saphenous openings. a. Superficial external pudendal vein,  b. Superficial epigastric vein, and  Tributaries of femoral artery c. Superficial circumflex iliac vein  B. Arteries a. Superficial external pudendal artery,   Superficial branches of femoral artery b. Superficial epigastric artery, and  c. Deep external pudendal artery—deep branch of femoral artery

Front of Thigh

93

Fig. 13.5: Saphenous opening

Fig. 13.6: Structures piercing through saphenous opening in male on right side

C. Lymph vessels: Lymphatics from superficial lymph nodes converge to saphenous opening. They pass through cribriform fascia and enter deep inguinal lymph nodes. 4. Comparative anatomy: Saphenous opening is present in fascia lata only in man. SAQ-5

Name the branches of femoral artery in femoral triangle

1. Superficial branches (Refer to Fig. 13.15) A. Superficial epigastric, B. Superficial circumflex iliac, and C. Superficial external pudendal. 2. Deep branches A. Deep external pudendal artery. It supplies deeper structures in the perineal region B. Profunda femoris and its branches a. Medial circumflex femoral artery and its branches b. Lateral circumflex femoral artery and its branches

Lower Limb

3

Exam-Oriented Anatomy

94

C. Muscular branches to muscles of anterior and medial compartment of thigh. D. The upper two perforating branches of profunda femoris artery arise in the femoral tiangle. LAQ-1

Describe femoral triangle (triangle of Scarpa) under following heads: 1. Site, 2. Boundaries, 3. Roof, 4. Floor, 5. Contents, 6. Relations, and 7. Applied anatomy

Introduction: It is subfascial

lar depression present in upper part of front of thigh.

1. Site A. It is present in front of the upper 1/3rd of the thigh below the inguinal ligament. B. In living person, it appears as a lar depression inferior to the inguinal ligament. C. It is best appreciated when the thigh is flexed, abducted, and laterally rotated.

Lower Limb

3

2. Boundaries A. Laterally: Medial border of sartorius. B. Medially: Medial border of adductor longus. It can be felt as a distinct ridge when the thigh is adducted against resistance. C. Base: Inguinal ligament. D. Apex: It is formed by the meeting point of the medial borders of adductor longus and sartorius. It is directed downward. 3. Roof A. Skin B. Superficial fascia containing a. Arteries: Superficial branches of femoral artery I. Superficial circumflex iliac, II. Superficial external pudendal, and III. Superficial epigastric artery. b. Veins: Tributaries of femoral vein I. Superficial circumflex iliac, II. Superficial external pudendal, and III. Superficial epigastric vein.

Front of Thigh

95

c. Nerves I. The femoral branch of the genitofemoral nerve (L1, L2) runs downwards. It is anterior to the femoral artery in anterior wall of femoral sheath. This nerve supplies an area of skin over the femoral . II. The lateral cutaneous nerve of the thigh (L2, L3) runs near the lateral angle of the femoral . C. Deep fascia and structures within it. These include a. Saphenous opening, b. Cribriform fascia, c. Terminal part of the saphenous vein, and d. Superficial inguinal lymph nodes. 4. Floor: It is muscular and hollow. It is best seen when thigh is flexed. The muscles are grouped as muscles forming medial and lateral sloping wall. They are described from medial to lateral (Fig. 13.7). A. Medial sloping wall is formed by a. Adductor longus medially. The medial border forms the boundary of the femoral , hence the whole muscle is included in the floor. b. Pectineus laterally. It is called key muscle of femoral

.

B. Lateral sloping wall is formed by a. Psoas major medially, and

3 Lower Limb

b. Iliacus laterally. It is covered by fascia iliacus (Fig. 13.7).

Fig. 13.7: Floor of the right femoral triangle

Exam-Oriented Anatomy

96

5. Contents (Fig. 13.8) A. Femoral sheath and its contents (from medial to lateral) a. Femoral Canal and its Contents, namely

FCC

I. Fibrofatty tissue, II. Cloquet lymph nodes (deep inguinal lymph node, or Rosenmüller lymph node), and III. Cloquet lymphatics (afferent and efferent lymphatics of these lymph nodes). b. Femoral vein and its tributaries I. Great saphenous vein and its tributaries i. Superficial epigastric, ii. Superficial circumflex iliac, and iii. Superficial external pudendal. II. Muscular veins III. Profunda femoris vein and its tributaries i. Medial circumflex femoral vein and its tributaries ii. Lateral circumflex femoral vein and its tributaries c. Femoral artery is central and dominant structure within the femoral and

Lower Limb

3

the branches of femoral artery within the femoral

are grouped as

I. Superficial branches i. Superficial epigastric, ii. Superficial circumflex iliac, and iii. Superficial external pudendal. II. Deep branches are i. Profunda femoris and its branches, * Medial circumflex femoral artery and its branches * Lateral circumflex femoral and its branches ii. Muscular branches, and iii. Deep external pudendal supplies muscles of thigh. iv. The upper two perforating branches of profunda femoris artery arise in the femoral triangle. B. Nerves a. Femoral nerves and its divisions (L2, L3, L4) I. Anterior division and its branches Short CUT i. Muscular branch to Sartorius ii. Medial CUTaneous nerve of thigh, and iii. Intermediate CUTaneous nerve of thigh.

Lower Limb

Fig. 13.8: Right femoral triangle and its contents

Front of Thigh 97

3

Exam-Oriented Anatomy

98

II. Posterior division and its branches QUADRI SAPH J i. Muscular branches to QUADRIceps * Rectus femoris, * Vastus medialis, * Vastus intermedius, and * Vastus lateralis. ii. Cutaneous branch—SAPHenous nerve iii. Articular branch to * Hip joint, and * Knee joint b. The nerve to the pectineus (L2, L3, L4) arises from the femoral nerve just above the inguinal ligament. It passes behind femoral sheath to reach the anterior surface of pectineus. c. The femoral branch of the genitofemoral nerve (L1, L2) occupies the lateral compartment of the femoral sheath. It runs along with the femoral artery. It supplies most of the skin over the femoral .

Lower Limb

3

d. The lateral cutaneous nerve of the thigh crosses the lateral angle of the . It runs on the lateral side of thigh. It ends by dividing into anterior and posterior branches. These supply anterolateral aspect of front of thigh and lateral aspect of gluteal region respectively. 6. Relations of vessels A. At base (from medial to lateral) VAN Femoral Vein, Femoral Artery, and Femoral Nerve. B. At apex (Fig. 13.9) (from anterior to posterior)

AVVA

a. Femoral Artery, b. Femoral Vein, c. Profunda femoris Vein, and d. Profunda femoris Artery 7. Applied anatomy

 Femoral artery * Pulsations of femoral artery are felt in femoral inguinal point against • Head of femur, and • Tendon of psoas major.

. They are felt at the mid-

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Fig. 13.9: Relations at the apex of femoral triangle from superficial to deep are AVVA (grandmother in Tamil)

* Stab wound injury at the apex of femoral vessels of lower limb (Refer to Fig. 13.9).

may be fatal as it cuts all the

 Femoral vein  Blood can be drawn from the femoral vein by feeling the pulsations of femoral artery and going just medially to it.  Femoral vein catheterization is used when rapid access to a large vein is needed.  Saphenous vein  Varicosities of saphenous veins are treated by Trendelenburg’s operation. The . tributaries of saphenous vein are tied in the femoral  Deep inguinal lymph nodes in femoral are enlarged in the

3 may be fatal as it cuts all vessels of

Fig. 13.10A: Structures damaged during stab wound injury at the apex of femoral triangle (AVVA— grandmother in Tamil)

 Pus may appear in the femoral behind the femoral sheath. It may travel to  The back of thigh along the perforating branches of the profunda femoris artery.  The adductor canal and even to the popliteal fossa along the femoral vessels.  Femoral hernia: The femoral ring is a weak area in the anterior abdominal wall. It is of a size of the little finger. The femoral ring is the usual site of a femoral

Lower Limb

 Infection of the skin of • Abdomen below umbilicus. • Gluteal region • Leg, sole and external genitalia. • Malignancy of fundus of uterus.  Stab wounds at the apex of femoral lower limb (Fig. 13.10A).

100

Exam-Oriented Anatomy

hernia. It is a protrusion of abdominal viscera (often a loop of small intestine) through the femoral ring into the femoral canal. A femoral hernia appears as a , inferolateral to the pubic tubercle. mass, often tender, in the femoral  Direction of course of femoral hernia (Figs 13.10B and 13.10C): As the hernia sac enlarges, it passes through the saphenous opening, then turns upwards. Here it may pass along the course of * Superficial circumflex iliac vessels, or * Superficial epigastric vessels. Note: Depending upon the pathway, it may be • Above the inguinal ligament, if it chooses the pathway along superficial epigastric vessels. • Below the inguinal ligament, if it chooses the pathway along superficial circumflex iliac vessels.

Lower Limb

3 Fig. 13.10B: Direction of course of right femoral hernia and reverse is the direction of reduction of hernia

Fig. 13.10C: Direction of course of right femoral hernia along the superficial epigastric artery

Front of Thigh

OLA-8

101

Name the fascia forming the femoral sheath

1. Anterior wall: Transversalis fascia. 2. Posterior wall: Fascia iliaca. 3. Lateral and medial wall: Fusion of fascia transversalis and fascia iliaca. SAQ-6

Enumerate the contents of femoral sheath

Contents of femoral sheath (from medial to lateral) are described as the contents of each compartment. 1. Medial compartment is femoral canal. Femoral Canal and its Contents are FCC • Fibrofatty tissue, • Cloquet lymph node (deep inguinal lymph node, or Rosenmüller lymph node), and • Cloquet lymphatics (afferent and efferent lymphatics of these lymph nodes). 2. Intermediate compartment is venous compartment. It contains femoral vein and its tributary—great saphenous vein. 3. Lateral compartment is arterial compartment. It contains A. Femoral artery, and B. Femoral branch of genitofemoral nerve in anterior wall. Femoral sheath

Introduction: It is the fascia covering femoral vessels in front of thigh region. 1. Gross A. Length: 4 cm. B. Shape: Conical (funnel)

.

a. Lateral wall is vertical. b. Medial wall is oblique directed downwards and laterally. 2. Formation A. Anterior wall: Fascia transversalis. B. Posterior wall: Fascia iliaca. C. Lateral and medial wall: Fusion of fascia transversalis and fascia iliacus. D. Below it blends with tunica adventitia of blood vessels. 3. Communications A. Superiorly opens into abdomen. B. Inferiorly merges with tunica adventitia of femoral vessels. 4. Contents of femoral sheath (from medial to lateral) are described as the contents of each compartment (Fig. 13.11).

3 Lower Limb

SN-8

102

Exam-Oriented Anatomy

A. Medial compartment: Femoral Canal Contains FCC • Fibrofatty tissue • Cloquet lymph nodes • Cloquet lymphatics B. Intermediate compartment—venous compartment: a. Femoral vein and its b. Tributary—great saphenous vein C. Lateral compartment—arterial compartment a. Femoral artery, and b. Femoral branch of genitofemoral nerve.

Lower Limb

3

Fig. 13.11: Right femoral sheath and its contents

5. Structures piercing the various walls A. Anterior wall is pierced by a. Superficial epigastric artery,  b. Superficial circumflex iliac artery, and  superficial branches of femoral c. Superficial external pudendal artery.  artery d. Deep external pudendal artery—deep branch of femoral artery B. Lateral wall: Femoral branch of genitofemoral nerve (L1, L2) C. Medial wall a. Lymph vessels, and b. Great saphenous vein. 6. Relations A. Anterior a. Skin, b. Superficial fascia, c. Fascia lata (deep fascia), and d. Inguinal ligament.

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B. Posterior a. Nerve to pectineus, b. Muscles deep to nerve to pectineus (from lateral to medial), I. Psoas major, and II. Pectineus. c. Structure deep to above muscles—capsule of hip joint. C. Lateral: Femoral nerve with its branches D. Medial: Adductor longus 7. Division: It is divided into three compartments by two vertical septa. A. Medial compartment: It is also called femoral canal. a. Fatty connective tissue. b. Cloquet lymph node which drains : Glans penis. I. Male II. Female

: Clitoris.

c. Cloquet lymph vessels. B. Intermediate or venous compartment which contains femoral vein. C. Lateral or arterial compartment which contains a. Femoral artery, and b. Femoral branch of genitofemoral nerve.

10. Applied anatomy

 Femoral canal is a potential weak point through which abdominal contents pass through.  Femoral hernia is a protrusion of abdominal contents through femoral canal. It is common in females

because of wider femoral ring. The femoral ring is wider

in female due to  Wider pelvis, and  Smaller vessels.  Any swelling lateral and below the pubic tubercle is most likely to be femoral hernia.  The direction of femoral hernia is:  Downwards through the femoral canal,  Forwards through saphenous opening,  Upwards along with superficial epigastric and superficial circumflex iliac vessels, and  Laterally towards anterior superior iliac spine.

3 Lower Limb

8. Function: It allows freedom for the femoral vessels to glide in and out beneath the inguinal ligament during movements of the hip joint. 9. Age changes: It is rudimentary in newborn. It is elongated after 1 year.

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104

 The femoral hernia is reduced in reverse direction as medially, downwards, backwards and upwards. Strangulated hernia resembles inflamed deep inguinal lymph node.  The pubic branch of inferior epigastric artery is a branch of external iliac artery. It runs to reach pubic symphysis. Normally, it runs lateral to femoral ring which is safe. If it passes medial to femoral ring, the course is said to be abnormal. Surgeons need to keep the abnormal course of the artery in mind while operating on femoral hernia.  Abnormal obturator artery: Obturator artery usually is a branch of the internal iliac artery. It gives a pubic branch which anastomoses with the pubic branch of the inferior epigastric artery. Occasionally, this anastomosis is large and the obturator artery then appears to be a branch of the inferior epigastric. The abnormal artery usually passes lateral to the femoral canal. It is safe in an operation to enlarge the femoral ring. Sometimes, the abnormal obturator artery may lie along the medial margin of the femoral ring, i.e. along the free margin of the lacunar ligament. Such an artery is likely to be cut, if an attempt is made to enlarge the femoral ring. (Refer to Fig. 13.13B and C)  This abnormal rare position is more frequent in males The incidence is 1:1000. SN-9

Lower Limb

3

than in females

.

Femoral canal

Introduction: It is a potential weakness present in smallest medial compartment of femoral sheath. 1. Features A. It is smallest, shortest and relatively empty compartment. B. It is medial or lymphatic compartment of femoral sheath. 2. Gross A. Length: 2 cm B. Diameter: About 1 cm C. Shape: Oval . It has a base and an apex. D. Base is wider and is called femoral ring. It is the mouth of femoral canal. It admits the tip of the little finger and is known as the femoral ring. E. Apex is narrow. 3. Attachments and relations (Fig. 13.12): The wall is firmly attached A. Anteriorly to inguinal ligament, B. Posteriorly to a. Pectineal ligament, and b. Fascia covering pectineus. C. Medially to lacunar ligament, and D. Laterally to the septum. It separates femoral canal from venous compartment.

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105

Fig. 13.12: Boundaries and relation of femoral canal

4. Contents: Femoral Canal Contains FCC Fibrofatty tissue Cloquet lymph nodes: There are two deep inguinal lymph nodes in relation to inguinal canal. One at the inguinal ring and another in the inguinal canal. Cloquet lymphatics A. Afferent lymphatics are from a. Superficial inguinal nodes, c. Glans penis in males d. Clitoris in females

, and

e. Deep lymphatics of the lower limb. B. Efferent lymphatics to external iliac group of lymph nodes. 5. Functions A. It is the route by which the efferent lymph vessels from the deep inguinal nodes pass to the abdomen B. It provides a ‘dead space’. The space allows expansion of the femoral vein during increased venous return. 6. Applied anatomy

 Femoral hernia  Introduction: It is the protrusion of abdominal contents through the femoral canal.  Gender: It is more common in female vessels.  Factors precipitating femoral hernia

because of wider pelvis and narrower

Lower Limb

3

b. Popliteal nodes,

Exam-Oriented Anatomy

106

 Increased intra-abdominal pressure,  Chronic cough,  Constipation,  Multiparous woman

,

 Tumours in the abdomen, and  Old age. Diagnosis: A swelling 4 cm below and lateral to pubic tubercle that increases on increased intra-abdominal pressure goes in favour of femoral hernia (Fig. 13.13A).

Lower Limb

3 Fig. 13.13A: Position of right femoral and inguinal hernia in relation to pubic tubercle

 As the hernia passes down through the narrow femoral ring, it is in a position of considerable danger. The sharp crescentic edge of the lacunar ligament may interfere with its blood supply. Herniorrhaphy: In repair of the strangulated femoral hernia, position of accessory obturator artery should be kept in mind (Fig. 13.13B and C).  The direction of femoral hernia is (Refer to Fig. 13.10B and C)  Downwards through the femoral canal,  Forwards through saphenous opening,  Upwards along with superficial epigastric and superficial circumflex iliac vessels, and  Laterally towards anterior superior iliac spine.  The femoral hernia is reduced in reverse direction as medially, downwards, backwards and upwards.

Front of Thigh

107

Fig. 13.13B: Normal course of pubic branch of right inferior epigastric artery

Fig. 13.13C: Abnormal course of pubic branch of right inferior epigastric artery

LAQ-2

Describe femoral artery under following heads 1. Origin, 2. Extent, 3. Course, 4. Relations, 5. Branches, and 6. Applied anatomy.

1. Origin: Femoral artery is the continuation of the external iliac artery distal to inguinal ligament. 2. Extent: It extends from mid-inguinal point to the apex of adductor canal. 3. Course: It passes downward and medially. The upper ½ part is in the femoral and the lower ½ is in the adductor canal. At the apex of the adductor canal, it pierces adductor magnus and continues as popliteal artery.

Lower Limb

3

Exam-Oriented Anatomy

108

4. Relations (Fig. 13.14A and B) A. At the base of femoral a. Medially—femoral Vein inside the femoral sheath b. Laterally—femoral nerve outside the femoral sheath and c. Anteriorly in the femoral sheath—femoral branch of genitofemoral nerve (L1, L2). B. At the apex of femoral , relations from anterior to posterior are • Femoral Artery, • Femoral Vein, • Profunda femoris Vein, and • Profunda femoris Artery.

AVVA

Lower Limb

3 Fig. 13.14A: Relations of right femoral vessels in femoral triangle and adductor canal

Fig. 13.14B: Relations of femoral vessels

Front of Thigh

109

Refer to Fig. 13.9. Box 13.1 Note: At all levels, the femoral artery lies between saphenous nerve and femoral vein.

C. Posterior relations from above downwards are a. Psoas major, b. Pectineus, and c. Adductor longus. 5. Branches A. Superficial a. Superficial epigastric artery, b. Superficial circumflex iliac artery, and c. Superficial external pudendal artery. B. Deep

Branch of profunda femoris artery

Branch

Type of anastomosis

Site

Lateral circumflex femoral artery

Ascending

Spinous

Anterior superior iliac spine

Medial circumflex femoral artery

Descending

–

Around knee joint

Transverse

Cruciate

Upper part of back of femur

Ascending

Trochanteric

Greater trochanter or femur

I. Lateral circumflex femoral artery. It gives i. Ascending branch: It takes part in spinous anastomosis. ii. Descending branch: It takes part in anastomosis around knee joint. iii. Transverse branch: It takes part in cruciate anastomosis. II. Medial circumflex femoral artery. It gives i. Ascending branch: It takes part in trochanteric anastomosis. It is chief artery of head and neck of femur. ii. Transverse branch: It takes part in cruciate anastomosis. III. Perforating: There are four perforating arteries. They perforate adductor magnus. One of the perforating arteries gives a large nutrient branch to the femur.

3 Lower Limb

a. Profunda femoris: It is the largest deep branch of femoral artery. It is equal to the size of femoral artery. It arises 4 cm below the inguinal ligament. It originates from posterolateral aspect of femoral artery. It spirals deep to femoral artery and passes downwards deep to adductor longus. It soon disappears through the gap between the pectineus and adductor longus. It gives following branches (Fig. 13.15).

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110

b. Deep external pudendal artery supplies blood to the scrotum in male and labium majus in female Box 13.2 Note: The word “pudendal” means “ashamed off”. The artery, vein and nerve having the word “pudendal” supplies all the structures which we are ashamed off.

c. Muscular branches to all the deep muscles of thigh. d. Descending genicular artery: It gives following branches I. Saphenous artery, and II. Muscular artery C. Termination: It continues as popliteal artery through an opening present in the adductor magnus.

Lower Limb

3

Fig. 13.15: Right femoral artery and its branches

6. Applied anatomy

 The pulsations of femoral artery can be felt just below the inguinal ligament over the head of femur, i.e. midway between the anterior superior iliac spine (ASIS) and pubic symphysis. It may be easily demonstrated using ultrasound (Fig. 13.16A). Refer to Fig. 13.10A.  Position of femoral vein can be localized as it lies just medial to the femoral artery.  Femoral artery can be compressed against the head of femur to control haemorrhage.

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111

Fig. 13.16: Relations of right femoral artery shown by the fingers of dorsal surface of left hand.

 The circulation of the limb is not affected in case of the blockage of the femoral artery.  In case of the blockage proximal part of the femoral artery, the circulation is maintained through cruciate and trochanteric anastomoses.  In case of the blockage of the arteries of the distal part of the thigh, the circulation is maintained through perforating branches of profunda femoris artery and its anastomosis with the branches of the popliteal artery.  Severe narrowing of arteries of the lower limb, with an inadequate collateral circulation, can lead to pain in muscles. The pain appears on walking and disappears with rest. The pain appears as the person takes a few steps. It is called intermittent claudication (claudication, limping).

OLA-9

What is the root value of femoral nerve?

Dorsal division of ventral rami of L2, L3, L4 OLA-10 What is the root value of obturator nerve?

Ventral division of ventral rami of L2, L3, L4 SAQ-7

Name the branches of femoral nerve

1. Muscular branches A. In pelvis. To a. Iliacus b. Pectineus B. In thigh a. Sartorius b. Quadriceps femoris I. Rectus femoris II. Vastus medialis

3 Lower Limb

Box 13.3 Note: The chief source of blood supply to the head and neck of the femur is derived from reticular branches of the medial circumflex femoral artery.

Exam-Oriented Anatomy

112

III. Vastus lateralis IV. Vastus intermedius 2. Cutaneous branches A. Saphenous nerve B. Medial CUTaneous nerve of thigh C. Intermediate CUTaneous nerve of thigh 3. Articular branches to hip and knee joint LAQ-3

Describe femoral nerve under following heads 1. Root value, 2. Branches, 3. Course and relations, and 4. Applied anatomy.

Lower Limb

3

1. Root value: It is formed by dorsal division of ventral rami of L2, L3 and L4. 2. Branches (Fig. 13.17) A. From the trunk a. Branch to iliacus, b. Branch to pectineus, and c. Vascular branches to femoral artery. B. From the divisions a. Anterior division (superficial branches) SARTCUT, S = SARTorius, CUTaneous . It has one muscular and two cutaneous branches. Muscular: SARTorius. CUTaneous • Medial CUTaneous nerve of thigh. It carries sensations of the skin of medial side of thigh. • Intermediate CUTaneous nerve of thigh. It carries sensations of the skin of front of thigh and takes part in patellar plexus. b. Posterior division. It gives following branches

QUADRI SAPH J

I. Muscular branches to QUADRIceps femoris i. Rectus femoris, ii. Vastus medialis, iii. Vastus intermedius, and iv. Vastus lateralis. II. Cutaneous branch is SAPHenous nerve. It supplies skin over i. Upper part of leg, and

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113

ii. Medial part of leg iii. Medial part of sole of foot. III. Articular branch to Joints. i. Hip joint, and i. Knee joint. IV. Vascular: To the femoral artery and its branches.

Fig. 13.17: Relations of branches of femoral nerve with femoral artery and its branches

Box 13.4 I. Cutaneous:  Medial cutaneous nerve of thigh.  Intermediate cutaneous nerve of thigh.  Note: The nerve to rectus femoris is usually double: The upper nerve gives a proprioceptive branch to the hip joint (Hilton’s law). The lower branch supplies rectus femoris.  The nerve to vastus medialis is massive muscular branch. It also supplies the capsule of the knee joint. It contains proprioceptive fibres to the knee joint. This explains the large size of the nerve. The nerve is often double. This is in accordance with Hilton’s law: Nerve supplying the muscle acting on the joint supplies the joint and the skin over the joint. • Knee joint, and • Hip joint. Contd.

Lower Limb

3

114

Exam-Oriented Anatomy Contd.

 Note the relations: Nerve to vastus medialis and saphenous nerve are on lateral side of femoral artery in adductor canal.  The nerve to vastus lateralis slopes steeply downwards with the descending branch of the lateral femoral circumflex artery and enters the anterior border of vastus lateralis.  The nerve to vastus intermedius passes deeply to enter the upper fleshy part of its anterior surface. II. Cutaneous: i. The saphenous nerve accompanies the • Femoral artery through the femoral and adductor canal, • Saphenous artery to the surface, and • Great saphenous vein through the leg, running behind it, and ending half way along the medial border of the foot. ii. Saphenous nerve being sensory, needs to reach the skin of medial side of leg and foot up to great toe. This it does by crossing the femoral artery in adductor canal from front.

Lower Limb

3

3. Course and relations (Fig. 13.18) A. In the pelvis: The nerve is formed in the substance of psoas major. It runs on the lateral border of psoas major between psoas major and iliacus. B. In the thigh: It enters thigh by passing deep to inguinal ligament. a. It lies on lateral side of femoral artery and outside the femoral sheath. b. The nerve runs 2.5 cm below inguinal ligament. It breaks like a “cauda equina” into numerous motor and sensory twigs. c. The two divisions of femoral nerve pass anterior and posterior to lateral circumflex femoral artery. C. Relations a. Anterior: Skin, superficial fascia and deep fascia. b. Posterior and medial: Psoas major. c. Posterior and lateral: Iliacus. 4. Applied anatomy

 Disease of hip joint may be referred to knee joint.  Femoral nerve  Neuroma of the femoral nerve or its branches is one of the differential diagnoses of lump in femoral  Accumulation of pus or blood in the psoas sheath may compress the femoral nerve.  Injury to femoral nerve causes paralysis of quadriceps femoris and affects extension of knee joint.

Front of Thigh

115

Lower Limb

3

Fig. 13.18: Right femoral nerve—L2, L3, L4 Note: 1. The symbol “

” at the end of nerve signifies the articular branch

2. The symbol “ ” at the end of nerve signifies the cutaneous branch

 Femoral nerve neuropathy: The main trunk of the femoral nerve may be compressed by • Entrapment of femoral nerve • Compression by retroperitoneal tumour. • Manifestations

Exam-Oriented Anatomy

116

• Wasting and weakness of quadriceps which results in • Difficulty in walking.  A localized neuropathy of the femoral nerve may occur in diabetes mellitus. Following are the characteristic clinical features • Wasting and weakness of quadriceps leading to considerable difficulty in walking. • Pain and paraesthesia on the anterior and medial aspects of the thigh. It extends along the medial aspect of the leg and foot.  The femoral nerve block can be easily achieved in the femoral . The anaesthetic solution is injected one-finger breadth lateral to the point of femoral pulse. It is just below the mid-inguinal point.  Injury to nerve results in atrophy of extensor muscles of thigh. It presents as weakness in extension of knee joint. There is loss of knee jerk. • Effect of femoral nerve injury in gunshot wounds results in – Motor loss: Inability to extend the knee. It is due to paralysis of quadriceps femoris muscle. – Sensory loss medial aspect of the thigh, leg and medial border of the foot as far as the ball of the big toe. It is due to involvement of

Lower Limb

3



Intermediate and lateral cutaneous nerves of the thigh, and



Saphenous nerve.



The saphenous nerve may be entrapped at the site where it pierces the roof of the adductor canal. This will cause pain and paraesthesia along the medial side of the knee and leg.

OLA-11 Name the nerves forming the subsartorial plexus

Subsartorial plexus is formed by

PAS .

• Posterior branch of medial femoral cutaneous nerve, • Anterior division of obturator nerve, and • Saphenous nerve. OLA-12 Attachments to patella

1. Vastus medialis, 2. Vastus intermedius, 3. Vastus lateralis, 4. Rectus femoris, and 5. Ligamentum patellae.

Front of Thigh

117

Fig. 13.19: Right patella showing the attachments of quadriceps femoris

LAQ-4

Describe adductor canal OR subsartorial canal OR Hunter’s canal under following heads: 1. Gross anatomy, 2. Boundaries, 3. Contents, and 4. Applied anatomy.

c. Subsartorial plexus which is formed by

PAS

I. Posterior branch of medial femoral cutaneous nerve. II. Anterior division of obturator nerve. III. Saphenous nerve This plexus supplies i. Fascia lata, and ii. Skin on medial side of knee.

3 Lower Limb

1. Gross anatomy: It is musculoaponeurotic passage or tunnel present in the middle 1/3rd of thigh A. Length: 6” or 15 cm. to 5 osseo-aponeurotic opening a. Extent: It extends from apex of femoral of the adductor magnus, i.e. it begins 4” below the inguinal ligament and ends 4” above the adductor tubercle. b. Location: It is situated on the middle 1/3rd of medial side of thigh. c. Shape: It is lar in cross-section. 2. Boundaries A. Anterolateral wall is formed by vastus medialis. B. Roof or medial wall is formed by a. Strong fascia that extends across vastus medialis to adductor longus in the upper part and vastus medialis to adductor magnus in the lower part. b. Sartorius muscle.

Exam-Oriented Anatomy

118

C. Floor: In the upper part, it is formed by adductor longus muscle and in the lower part, it is formed by adductor magnus muscle (Figs 13.20 and 13.21). D. Apex is formed by meeting point of vastus medialis and adductor muscle on linea aspera of femur. E. Function: It provides the passage for femoral vessels. 3. Contents A. Contents coursing through upper end to lower end. a. Femoral artery: It lies anterior to the femoral vein in upper part and medial to the vein in the lower part. b. Femoral vein, and c. Saphenous nerve—longest cutaneous nerve of the body. B. Other contents a. Descending genicular artery (branch of femoral artery) and its branches into I. Superficial branch saphenous artery: It crosses the femoral artery anteriorly from lateral to medial side. II. Deep branch muscular artery which enters vastus medialis and joins the arterial anastomosis around the knee. b. Anterior and posterior divisions of obturator nerve. c. Nerve to vastus medialis: It lies lateral to the femoral artery.

Lower Limb

3

d. Deep lymph vessels. e. Vascular branch of the anterior division of obturator nerve. f. Genicular branch of the posterior division of obturator nerve. The 3rd perforator which lies in the middle of the thigh is known as Hunterian perforator. It connects the great saphenous vein to the femoral vein in the adductor canal or the Hunter’s canal.

Fig. 13.20: Floor in the upper part of adductor canal

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119

Fig. 13.21: Floor in the lower part of adductor canal

4. Applied anatomy

3 Lower Limb

 Adductor canal is the site of ligation of femoral artery.  A tourniquet is applied against the linea aspera in adductor canal. It is to arrest bleeding of popliteal vessels in the following situations: a. In rupture of aneurysm of popliteal artery, b. For the treatment of aneurysm of popliteal artery. c. Below knee amputation surgery.  The surgical approach to the femoral artery in the adductor canal. • The incision is taken on the medial aspect of the lower thigh. • Sartorius is retracted medially. • Fascial roof of the canal divided.  The saphenous nerve may be entrapped at the site where it pierces the roof of the adductor canal. This will cause pain and paraesthesia along the medial side of the knee and leg.

14 Medial Side of Thigh

OLA-13 Enumerate the muscles of adductor compartment

Muscles are grouped as 1. Intrinsic A. Adductor longus, B. Adductor brevis, C. Adductor magnus, D. Gracilis, and E. Pectineus. 2. Extrinsic: Obturator externus lies deep in this region. OLA-14 Enumerate the muscles supplied by obturator nerve

It has two divisions 1. Anterior division supplies A. Pectineus, B. Adductor longus, C. Gracilis, and D. Adductor brevis. 2. Posterior division supplies A. Obturator externus, B. Adductor brevis, if not supplied by anterior division, and C. Adductor magnus. LAQ-5

Describe obturator nerve under following heads 1. Root value, 2. Course, 3. Branches, 4. Relations, and 5. Applied anatomy. 120

Medial Side of Thigh

121

Table 14.1: Branches and distribution of obturator nerve Particulars • Muscular

• Vascular • Articular • Miscellaneous

Anterior • • • • • • • • •

Pectineus, Gracilis, Adductor longus, and Adductor brevis Femoral artery Hip joint Subsartorial plexus supplying Fascia lata, and Skin of the medial side of thigh

Posterior • Obturator externus • Adductor brevis, and • Adductor magnus • Popliteal artery • Knee joint • Capsule of knee joint

3 Lower Limb

Introduction: It is a nerve of the adductor compartment of the thigh. It supplies the adductor muscles and the skin over the medial side of thigh. 1. Root value: It arises from ventral division of ventral rami of L2, L3 and L4. 2. Course: It extends from pelvis to knee joint. A. In the pelvis, it a. Is formed within the substance of psoas major muscle, b. Passes on the medial border of psoas major, c. Lies behind the common iliac vessels, d. Runs lateral to the internal iliac vessels, e. Passes along the lateral wall of pelvis, and f. Passes through obturator foramen and divides into anterior and posterior divisions in the obturator notch. B. In the thigh a. The adductor brevis is sandwiched between anterior and posterior divisions of obturator nerve. b. The anterior division runs in front of obturator externus muscle in the upper part. It lies in front of adductor brevis muscle in the lower part. It runs behind the pectineus and adductor longus. c. The posterior division perforates the upper border of obturator externus and gives a branch to it. It lies deep to the posterior surface of adductor brevis. It runs in the thigh vertically on adductor magnus. 3. Branches: They are grouped as branches from trunk, anterior division and posterior division (Fig. 14.1). A. Branches from the trunk in the pelvis are a. Peritoneal branch to lateral pelvic wall. b. Branch to the hip joint: It springs from the main nerve within the obturator canal. It passes laterally and gives many twigs to the I. Pubofemoral ligament, II. Synovial membrane, and III. Ligament of the head of the femur.

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3

Fig. 14.1: Branches and relations of right obturator nerve L2, L3, L4

4. Relations Table 14.2: Relations of obturator nerve Division • Anterior • Posterior

• • • •

Anterior Adductor longus, and Pectineus Adductor longus, and Adductor brevis

Posterior • Adductor brevis • Adductor magnus

Medial Side of Thigh

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5. Applied anatomy

 The obturator nerve supplies both hip and knee joints. So, pain of one joint gives referred pain to other joint.  Injury to obturator nerve is uncommon. A penetrating wound may injure obturator nerve and results in the weakness of adduction of the hip joint.  Peritonitis in the lateral pelvic wall may irritate the obturator nerve. The pain in such conditions may be referred to the medial side of the  Hip joint,  Distal thigh, and  Back of knee joint.  Obturator nerve may be involved with femoral nerve in retroperitoneal tumours.  A nerve entrapment syndrome leading to chronic pain on the medial side of thigh may occur in athletes with big adductor muscles.  There is a spasm of the adductors of thigh in certain intractable cases of spastic paraplegia. This may be relieved by surgical division of the obturator nerve.  Compression of the obturator nerve in the obturator canal may occur due to obturator hernia or osteomyelitis. There is pain and later weakness of the adductors of the thigh.  Scissors gait in cerebral palsy due to adductor spasm is treated by partial severance (cutting) of obturator nerve.

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3

15 Gluteal Region

SN-10

Ischial tuberosity

1. It is a tuberosity present on lower part of the dorsal surface of ischium. 2. Morphology: It is an example of traction epiphysis. 3. Relations A. In standing position, it is covered by gluteus maximus. In the sitting position, the muscle slips laterally so that weight is taken directly on the bone. B. It forms the lateral wall of ischiorectal fossa. 4. Attachments: It is rough and divided by a transverse ridge into upper quadrilateral and lower triangular (Table 15.1 and Fig. 15.1). Table 15.1: Muscles and ligaments attached to ischial tuberosity

• Upper • Lower

Part

Attachments

• Upper lateral

• Semimembranosus.

• Lower medial

• Semitendinosus and long head of biceps femoris

• Lateral

• Ischial fibres of adductor magnus

• Medial

• Medial margin gives attachment to sacrotuberous ligament covered with fibrofatty tissue and transmits the body weight in sitting position.

A. Apart from hamstring muscles, following structures are attached to ischial tuberosity a. Inferior gemellus from the upper margin of ischial tuberosity b. Quadratus femoris arises from lateral border below the inferior gemellus c. Obturator internus d. Superficial transverse muscles of perineum e. Sacrotuberous ligament arises from medial border of ischial tuberosity. 124

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125

Fig. 15.1: Muscles attached to the right ischial tuberosity

5. Applied anatomy

OLA-15 Which is the key muscle in gluteal region?

Piriformis is the key muscle in understanding the anatomy of gluteal region. OLA-16 Name the nerve supplying gluteal maximus. What is the root value?

Inferior gluteal nerve (L5, S1, S2)

3 Lower Limb

 Weaver’s bottom: It is the inflammation of bursa. It lies between gluteus maximus and ischial tuberosity. It is inflamed and enlarged in persons whose occupation invites long periods of sitting.  In debilitated old people, pressure can cause discomfort while sitting.  It is one of the sites of bedsores in paralyzed patients and in immobilized patients.  Nelaton’s line joins the anterior superior iliac spine to the ischial tuberosity. It should normally lie above the greater trochanter.  The line passing through or below the trochanter indicates shortening at the head or neck of the femur.  The surface markings of the sciatic nerve can be represented by a line drawn between posterior superior iliac spine and ischial tuberosity. It curves outwards and downwards. It passes through a point midway between the greater trochanter and ischial tuberosity.  Pudendal nerve block: In pudendal nerve block, the needle is inserted into the pudendal canal along the medial side of tuberosity. The canal lies 1" deep to ischial tuberosity.

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Exam-Oriented Anatomy

OLA-17 Name the nerve supplying gluteus medius. What is the root value?

Superior gluteal nerve (L4, L5, S1) OLA-18 Enumerate the actions of gluteus maximus

Actions of gluteus maximus 1. Powerful extensor of the hip joint. 2. Powerful lateral rotator of the thigh. 3. It is important in rising from sitting position or in climbing stairs. 4. Supports the extended knee. 5. Upper fibres are abductor of the thigh. OLA-19 Enumerate the actions of gluteus medius

Actions of gluteus medius 1. It is powerful abductors of the thigh. 2. Its anterior fibres are medial rotator. 3. Its most important action is to maintain the balance of the body when opposite foot is off the ground as in walking and running. OLA-20 Enumerate the bones under cover of gluteus maximus

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Bones 1. Elements of hip bone A. Ilium, and B. Ischium. 2. Sacrum and coccyx, and 3. Upper end and greater trochanter of femur. SAQ-8

Enumerate the muscles under cover of gluteus maximus

Box 15.1 Muscles: Muscles can be recollected by grouping them as key muscle, ½, 1, 2, 3 and 4 muscles (Key muscle, ½ muscles, 1, group of 2, 3, and 4)

Key muscle is piriformis. ½ muscle is reflected head of rectus femoris. The single (1) muscle is quadratus femoris. The muscles in the pair (2) are A. Gemelli a. Superior, and b. Inferior

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B. Obturator a. Internus, and b. Externus. The muscles in the trio (3) are A. Gluteus maximus is excluded as we are describing structures under the same, B. Gluteus medius, and C. Gluteus minimus. The muscles in group of (4) are A. Semimembranosus, B. Semitendinosus, C. Ischial fibres of adductor magnus, and D. Biceps femoris. SAQ-9

Enumerate the nerves under cover of gluteus maximus

Nerves: The key nerve in this region is sciatic nerve. The other nerves under cover of gluteus maximus are the nerves supplying the muscles present in this region. Key nerve is sciatic nerve (L4, L5, S1, S2, S3). Nerve to quadratus femoris (L4, L5, S1), Nerve to obturator internus (L5, S1, S2), Superior gluteal nerve (L4, L5, S1), Inferior gluteal nerve (L5, S1, S2), Pudendal nerve (S2, S3, S4), Posterior cutaneous nerve of thigh (S2, S3), and Perforating cutaneous nerve (S2, S3) branch of posterior cutaneous nerve of thigh.

OLA-21 Enumerate the vessels under cover of gluteus maximus

Vessels can be remembered by mnemonic SIATICA Superior gluteal artery. Inferior gluteal artery. Ascending branch of medial and lateral circumflex femoral arteries (profunda femoris). Trochanteric anastomosis: The arteries taking part in trochanteric anastomosis are the arteries beginning with 1st 3rd letters of the key word “sciatica”. Internal pudendal vessels. Cruciate anastomosis: The arteries are above the trochanteric anastomosis and artery below the cruciate anastomosis. Ascending branch of 1st perforating artery. SN-11

Gluteus maximus

Introduction: This is the largest and the most superficial of the gluteal muscles. It is characterized by its large fibre bundles. It is quadrilateral muscle.

3 Lower Limb

1. 2. 3. 4. 5. 6. 7. 8.

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Exam-Oriented Anatomy

1. Origin A. Aponeurotic: Aponeurosis of erector spinae. B. Bony a. Posterior gluteal line. b. Area posterior to the posterior gluteal line. c. Outer sloping area of the dorsal segment of the iliac crest. d. Dorsal surface of lower 2 pieces of sacrum e. Side of coccyx C. Ligamentous: Sacrotuberous ligament. D. Fascial: Fascia covering the gluteus medius. 2. Insertion (Fig. 15.2) A. Superficial major part (3/4th part) is inserted into iliotibial tract. B. Deep, lower 1/4th part is inserted into gluteal tuberosity.

Lower Limb

3 Fig. 15.2: Proximal and distal attachments of right gluteus maximus

3. Features A. It is a. Rhomboidal, that is to say, it is oblong whose opposite borders are parallel, but whose angles are not right angled. b. Most powerful and bulkiest muscle in man. c. Largest and the most superficial of the gluteal muscles, d. Most fasciculated (clustered together) muscle in the body. e. Largely responsible for the prominence of the gluteal region. f. Known as the deltoid of the hip joint. 4. It has a coarse texture due to the presence of a large number of fibrous septa in its substance.

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5. Blood supply A. Arterial a. Superior gluteal, branch of posterior division of internal iliac artery and b. Inferior gluteal arteries, branch of anterior division of internal iliac artery. B. Venous drainage: Veins form a plexus. 6. Nerve supply: Inferior gluteal nerve (L5, S1, S2) 7. Actions A. It is a powerful extensor of the hip joint. B. It is a powerful lateral rotator of the thigh. C. It acts in rising from sitting position and in climbing the staircase. D. It supports the extended knee. E. It is abductor of the thigh. F. The upper fibres of the muscle are a strong abductor of the thigh. 8. Bursae related: There are usually three bursae beneath the muscle. They are bursa over A. Ischial tuberosity, B. Greater trochanter, and C. Vastus lateralis. Box 15.2  Why the gluteal region is ideal site for injection? It is a large, thick muscle with coarse fasciculi that can be easily separated without damage.  We do not sit on your gluteus maximus; we sit on the fatty fibrous tissue and the ischial bursa that lie between the ischial tuberosity and the skin.  The muscle helps in climbing the staircase. In case of paralysis, patient needs to climb on one’s self. Box 15.3 Word of caution : To avoid injury to the underlying sciatic nerve, the injection should be given in the upper outer quadrant of the buttock.

9. How to feel the muscle by oneself: If you climb stairs and put your hand on your buttock, you will feel the gluteus maximus contract strongly. 10. Muscle testing: Patient lies prone. The right hand of physician presses the patient’s right leg downwards. Patient is requested to extend his hip against resistance. Physician feels the contracting gluteus maximus muscle by left hand. 11. Applied anatomy

 The sciatic nerve is explored by exposure at the lower border of gluteus maximus.

3 Lower Limb

It is interesting to know

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130

 The bursae associated with the gluteus maximus are prone to inflammation and are painful.  The trochanteric bursa separates superior fibres of the gluteus maximus from the greater trochanter. The trochanteric bursa is commonly the largest of the bursae formed in relation to bony prominences and is present at birth. Other such bursae appear to form as a result of postnatal movement.  The ischial bursa separates the inferior part of the gluteus maximus from the ischial tuberosity; it is often absent.  The gluteofemoral bursa separates the iliotibial tract from the superior part of the proximal attachment of the vastus lateralis, a thigh muscle.  Gluteus muscle is paralysed in muscular dystrophy.  Climbing on one’s self: The patient with gluteus maximus paralysed, cannot standup from a sitting posture without support. Such patients rise gradually. He supports his hands first on legs and then on the thighs; and lastly, they stand. This is called climbing on oneself. This can be seen in pseudohypertrophy with muscular dystrophy syndrome (Duchenne muscular dystrophy). LAQ-6

Describe the structures under cover of gluteus maximus 1. Bones, 2. Muscles, 3. Nerves,

Lower Limb

3

4. Vessels, 5. Joints, 6. Ligaments, and 7. Bursae. Box 15.4  Note: There are about 35 to 40 structures deep to gluteus maximus. Author as a junior teacher used to find it difficult to memorize all structures. He applied the concept “Divide and rule”. The structures can be grouped as muscles, nerves supplying these muscles, arteries and veins of this region, bones, joints, ligaments of the joint, bursae related to the bones. Vessels can be remembered by mnemonic ‘SIATICA’ Muscles: Muscles can be recollected by grouping them as key muscle, ½, 1, 2, 3 and 4 muscles (key muscle, ½ muscles, 1, group of 2, 3, and 4)

1. 2. 3. 4. 5.

Bones: Refer to OLA-20 Muscles: Refer to SAQ-8 Nerves: Refer to SAQ-9 Vessels: Refer to OLA-21 Joint: Hip and sacroiliac joints.

131

Fig. 15.3: Structures under cover of the right gluteus maximus

6. Ligaments A. Sacrotuberous, B. Sacrospinous, and C. Ischiofemoral ligament. 7. Bursae: Under cover of gluteus maximus A. Trochanteric bursa: Bursa present at greater trochanter. B. Bursa over ischial tuberosity. C. Bursa between gluteus maximus and vastus lateralis. SN-12

Gluteus medius

Introduction: It is a fan-shaped bony pelvis. 1. Features A. It is fan-shaped

muscle and covers the lateral surface of the

,

B. The deep fascia over the gluteus medius is thick, dense, opaque and pearly white, and C. It is post-axial muscle.

3 Lower Limb

Gluteal Region

132

Exam-Oriented Anatomy

2. Proximal attachment: Gluteal surface of ilium between anterior and posterior gluteal lines. Box 15.5 Note: The gluteus medius and minimus are like twins. They share same proximal and distal attachments, nerve supply, blood supply and actions.

3. Distal attachment: Lateral surface of greater trochanter of femur along the oblique line that slopes downward and forward. Its distal attachment has a strong expansion that crosses the capsule of hip joint. 4. Nerve supply: Superior gluteal nerve (L4, L5, S1). It lies in the interval between gluteus medius and minimus; it divides into superior and inferior branches. The superior branch supplies the gluteus medius and the inferior branch supplies the gluteus medius, gluteus minimus and tensor fasciae latae.

Lower Limb

3

5. Relations: Structures deep to the gluteus medius are A. Superior gluteal nerve, B. Deep branch of the superior gluteal artery, C. Gluteus minimus, and D. Trochanteric bursa of the gluteus medius. 6. Actions (Fig. 15.4) A. The most important action is to maintain the balance of the body when the opposite foot is off the ground, as in walking and running. They do this by preventing the opposite side of the pelvis from tilting downwards under the influence of gravity. B. The gluteus medius and minimus muscles are powerful abductor of the thigh at the hip joint when the limb is free to move. It occurs in all positions of the lower limbs. C. The anterior fibres of gluteus medius and minimus with the help of tensor fasciae latae produce medial rotation. It is restricted by tension in the lateral rotators and the Ischiofemoral ligament. 7. Testing the gluteus medius: It is performed while the person is prone with the leg flexed to a right angle. The person abducts the thigh against resistance. The gluteus medius can be palpated inferior to the iliac crest, posterior to the tensor of the fascia lata. It is also contracts during abduction of the thigh. 8. Applied anatomy

 Intramuscular injection is given in the upper and lateral quadrant of the gluteal region. The needle enters gluteus medius.  Gluteus medius and minimus are supplied by superior gluteal nerve. Injury to the superior gluteal nerve results in a characteristic motor loss. It results in a gluteus medius limp.  Gluteus medius and minimus and poliomyelitis: The gluteus medius and minimus are supplied by the superior gluteal nerve. They may be paralysed when poliomyelitis involves the lower lumbar and sacral segments of the spinal

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133

Fig. 15.4: Demonstrating the chief function of gluteus medius and gluteus minimus

SAQ-10 Cruciate anastomosis

1. Site: Cross-like anastomosing arteries are seen in the lower part of the gluteal region. They are present at the root of the greater trochanter between quadratus femoris and adductor magnus. To be precise, cruciate anastomosis is present at the middle of lesser trochanter (Fig. 15.5). 2. Arteries taking part A. Transverse branch of a. Medial circumflex femoral artery, and b. Lateral circumflex femoral artery.

3 Lower Limb

cord. Paralysis of these muscles seriously interferes with the ability of the patient to tilt the pelvis when walking.  The stability of the hip joint when a person stands on one leg depends on three factors.  The gluteus medius and minimus must be functioning normally,  The head of the femur must be located normally within the acetabulum, and  The neck of the femur must be intact and must have a normal angle with the shaft of the femur. If any one of these factors is defective, then the pelvis sinks downward on the opposite, unsupported side, the patient is then said to exhibit a positive Trendelenburg’s sign.  Anterior approach of surgical exposure of the hip joint: It passes between gluteus medius and minimus laterally and sartorius medially. It then divides the reflected head of rectus femoris and exposes the anterior aspect of the hip joint. More room may be obtained by detaching these glutei from the external aspect of the ilium.

134

Exam-Oriented Anatomy

B. Descending branch of inferior gluteal artery, and C. Ascending branch of first perforating artery.

Fig. 15.5: Posterior surface of upper end of femur at the level of middle of lesser trochanter showing cruciate anastomosis

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3

3. Applied anatomy : This establishes the collateral circulation between internal iliac artery and profunda femoris artery. This is established in case of ligature of the femoral artery proximal to the attachment of profunda femoris artery.

16 Popliteal Fossa

SAQ-11 Enumerate the muscles forming the boundaries of popliteal fossa

Boundaries (Fig. 16.1): It is bounded by 1. Superomedially A. Semimembranosus medially, and B. Semitendinosus laterally. 2. Superolaterally superficially: Tendon of biceps femoris. 3. Inferolaterally A. Lateral head of gastrocnemius, and B. Plantaris. 4. Inferomedially: Medial head of gastrocnemius. SAQ-12 Enumerate the structures forming the floor of popliteal fossa

Floor (anterior wall) is formed by following structures. They are from above downward (Fig. 16.1). 1. Popliteal surface of femur. It is overlaid with fat, 2. Capsule of knee joint, 3. Oblique popliteal ligaments are the fibers of the posterior part of the fibrous capsule. They are parallel to the popliteus and, so, tend to save it from being overstretched, 4. Popliteal muscle, and 5. Fascia covering popliteus muscle: It is derived from semimembranosus muscle. It is very thin laterally, and thick and strong medially. Floor is pierced by A. Middle genicular vessels (branch/tributary of popliteal artery/vein), B. Middle genicular nerve (branch/tributary), and C. Genicular branch of posterior division of obturator nerve (L2, L3, L4). 135

Exam-Oriented Anatomy

136

Fig. 16.1: Boundaries and floor of the right popliteal fossa

SAQ-13 Contents of popliteal fossa

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3

1. Main content of popliteal fossa is fat. 2. The most important contents are A. Tibial nerve, B. Common peroneal nerve, C. Popliteal artery and its branches. It gives a. Muscular branches to muscles of popliteal fossa, b. Sural arteries to gastrocnemius, and c. Genicular branches to knee joint. D. Popliteal vein and its muscular tributaries. LAQ-7

Describe popliteal fossa under following heads 1. Gross anatomy 2. Boundaries, 3. Roof, 4. Floor, 5. Contents, 6. Relations, and 7. Applied anatomy.

Popliteal Fossa

Introduction: It is a diamond

137

shaped fossa present on posterior aspect of knee

joint. It is homologous with cubital fossa, present in front of the elbow joint. 1. Gross anatomy A. Shape of popliteal fossa in various positions a. Flexed knee: It is diamond

shaped. It is hollow area between the

hamstring tendons. b. In the extended knee: Hamstring tendons lie against the femoral condyles. The fat of the popliteal space bulges the roof of the fossa. B. Communication: It communicates proximally to adductor canal and distally to posterior part of leg.

3. Roof (posterior wall) is formed by following structures from superficial to deep. A. Skin, B. Superficial fascia, and C. Fascia lata. It is strengthened by transverse fibres. It continues below as fascia cruris. It is pierced by a. Sural nerve (cutaneous branch of tibial nerve), b. Sural communicating nerve, branch of common peroneal nerve, c. Posterior femoral cutaneous nerve of thigh, d. Short saphenous vein, and e. Lateral cutaneous nerve, branch of common peroneal nerve.

3 Lower Limb

2. Boundaries: It is bounded by A. Superomedially a. Superficially I. Semimembranosus medially, and II. Semitendinosus laterally. III. Supplemented by the i. Gracilis, ii. Sartorius, and iii. Adductor magnus. b. Deep: Medial supracondylar ridge of femur. B. Superolaterally a. Superficially: Tendon of biceps femoris. b. Deep: Lateral supracondylar ridge of femur C. Inferolaterally a. Lateral head of gastrocnemius, and b. Plantaris. D. Inferomedially: Medial head of gastrocnemius.

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138

4. Floor (anterior wall) is formed by following structures. They are from above downward. A. Popliteal surface of femur. It is overlaid with fat, B. Capsule of knee joint, C. Oblique popliteal ligaments are the fibres of the posterior part of the fibrous capsule. They are parallel to the popliteus and, so, tend to save it from being overstretched. D. Popliteal muscle. E. Fascia covering popliteus muscle: It is derived from semimembranosus muscle. It is very thin laterally, thick and strong medially. F. Floor is pierced by a. Middle genicular vessels (branch/tributary of popliteal artery/vein), b. Middle genicular nerve, and c. Genicular branch of posterior division of obturator nerve (L2, L3, L4) (Fig. 16.1). 5. Contents A. Main content of popliteal fossa is fat. B. The most important contents are

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3

a. Tibial nerve, one of two terminal branches of sciatic nerve given at the upper part of popliteal fossa. In the fossa, this nerve gives branches to I. Both heads of the gastrocnemius, II. Plantaris, III. Popliteus, IV. Soleus, a muscle of the leg lying deep to the gastrocnemius, and V. Genicular branches to the knee joint. b. Common peroneal nerve: It is one of two terminal branches of sciatic nerve given at the upper part of popliteal fossa. It does not have any muscular branches in popliteal fossa except branch to short head of biceps. It gives two cutaneous and two articular branches in popliteal fossa (Fig. 16.2). These are I. Sural communicating nerve (that joins the sural nerve), II. Lateral cutaneous nerve of the calf that supplies skin on the lateral side of the back of the leg, and III. Genicular branches to the knee joint. c. Popliteal artery: It gives I. Muscular branches to muscles of fossa, II. Sural arteries to gastrocnemius, and III. Genicular branches to knee joint. d. Popliteal vein and its muscular tributaries.

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139

Fig. 16.2: Branches of sciatic nerve in popliteal fossa

C. The less important contents are a. Descending genicular branch of posterior division of obturator nerve b. Posterior cutaneous nerve of thigh c. Popliteal lymph nodes I. Number: They are 6 in number arranged in 3 sets (from superficial to deep), i. Superficial nodes, ii. Intermediate nodes, iii. Deep nodes, II. Afferent lymphatics: They receive lymphatics from i. Superficial nodes, and ii. Deep parts of the leg and foot. III. Palpation of lymph nodes: They are palpated by the flexing of the knee which relaxes the deep fascia of the roof of the popliteal fossa. d. Pad of fat

3 Lower Limb

Box 16.1 Note: The short saphenous vein drains the lateral side of the foot towards the calf, ascends to pierce the deep fascia in the lower or middle 1/3rd of the calf (not in the popliteal fossa).

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140

6. Relations: The relations of the contents are described at three different levels in Table 16.1. Table 16.1: Relations of structures in the popliteal fossa In upper part

In middle part

In lower part

• Relations from medial to lateral AVN

• Relations from anterior posterior AVN

• Relations from medial to lateral NVA

• Popliteal artery

• Tibial nerve

• Popliteal vein

• Popliteal vein

• Popliteal vein

• Tibial nerve

• Tibial nerve

• Popliteal artery

Popliteal artery

7. Applied anatomy

 Popliteal pulse is felt behind the knee, deep in the popliteal fossa with knee flexed.

Lower Limb

3

Fig. 16.3A: Relations of right popliteal artery with other structures in the popliteal fossa

a k. Simile Fig. 16.3B: Plumb vksdc of tibial nerve is given to plumb. The tibial nerve drops from superior angle to inferior angle of popliteal fossa like a plumb

 The tibial nerve is rarely injured in popliteal fossa. Injury to tibial nerve in popliteal fossa is associated with motor paralysis of muscles supplied by it.  Foot is dorsiflexed at ankle joint and held in eversion.  There is a sensory loss on entire sole of foot.  All the popliteal swelling may not be from popliteal fossa. Hence, it is customary to examine the knee joint.

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141

 Following are the causes of swelling in the popliteal fossa.  A pulsatile midline swelling in the popliteal fossa is due to aneurysm of popliteal artery. It demonstrates a bruit on auscultation. It is an audible rumbling made by turbulent blood flow. – It compresses the popliteal vein and results in oedema of leg. It favours formation of thrombosis.  Arterial adventitial cyst: It is a swelling arising from tunica adventitia of popliteal artery.  Features of popliteal abscess  Causes • Infection of popliteal lymph nodes, and • Acute suppurative osteomyelitis of the lower end of the femur.  Features • It is slow to heal when drained, • It presses on the nerves and vessels of the popliteal fossa, and • It is drained through an incision on the lateral aspect, anterior to the tendon of biceps femoris.  Popliteal swelling is unusually painful because of the  Unyielding character of the walls of the fossa, and

 A popliteal cyst (Baker’s cyst) is a synovial out pouching that arises from the posteromedial aspect of the knee joint. The synovial membrane of the knee joints out pouches between the medial head of gastrocnemius and the semimembranosus tendon to lie medially within the popliteal fossa. It disappears in flexion of knees.  Pes anserinus (like a goose)

: It is a bursa around the tendons of sartorius,

gracilis, and semitendinosus.  Sebaceous cyst: A swelling of sebaceous gland in the skin.  Swelling of soft tissues: Lipoma, sarcoma.  Swelling of vein: Varicosities of the short saphenous vein in the roof of the fossa.  Swelling of knee joint—joint effusion.  Tumour of the lower end of femur or upper end of tibia.  Popliteal artery lies directly on the bone and can be damaged by supracondylar fractures. SAQ-14 Enumerate the branches of popliteal artery

Refer to Flowchart 16.1

3 Lower Limb

 Fatty areolar tissue in which they are embedded.

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142

OLA-22 Name the terminal branches of popliteal artery

Terminal branches: Two terminal branches are 1. Anterior tibial artery, and 2. Posterior tibial artery. LAQ-8

Describe popliteal artery under following heads 1. Origin, 2. Termination, 3. Course, 4. Extent, 5. Relations, 6. Branches, and 7. Applied anatomy.

Introduction: Popliteal artery is deeply placed structure in popliteal fossa. 1. Origin: It is a continuation of the femoral artery at the 5th osseo-aponeurotic opening in adductor magnus. 2. Termination: It terminates at the lower border of popliteus by dividing into anterior and posterior tibial arteries.

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3. Course: It runs downwards and laterally and passes in between two condyles. It ends at the lower border of popliteus. It terminates (Fig. 16.4). 4. Extent: It extends a hand’s breadth above the knee to a hand’s breadth below the knee. It is about 8 (20 cm) long. 5. Relations: For convenient purpose, it is divided into upper, middle and lower 1/3rd of popliteal fossa (Fig. 16.5). A. In the upper 1/3rd a. Anterior or deep I. Popliteal surface of the femur and II. Fat. b. Posterior or superficial: Semimembranosus. c. Laterally I. Popliteal vein, and II. Tibial nerve. B. Middle 1/3rd a. Anterior or deep: Capsule of knee joint b. Immediate posteriorly: Popliteal vein c. Most posterior or superficial: Tibial nerve d. Medially

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Fig. 16.4: Course and branches to right popliteal artery

6. Branches (Flowchart 16.1) A. Muscular a. Upper 2 to 3 supply the I. Adductor magnus, and II. Hamstrings.

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I. Medial condyle of femur II. Medial head of gastrocnemius e. Laterally I. Lateral head of gastrocnemius, II. Plantaris, and III. Lateral condyle of femur C. Lower 1/3rd a. Anteriorly or deep: Popliteus with its fascia. b. Posterior or superficial I. Plantaris, II. Lateral head of gastrocnemius, and III. Nerve to lateral head of gastrocnemius. IV. Posterior: Soleus muscle.

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3 Fig. 16.5: Relations of the right popliteal artery (seen from medial side)

Flowchart 16.1: Branches of politeal artery

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b. Lower muscular or sural branches supply I. Gastrocnemius, II. Soleus, and III. Plantaris. c. Upper muscular branches terminate by anastomosing with the 4th perforating artery (Fig. 16.6).

Fig. 16.6: Anastomoses between 4th perforating artery and superior muscular branch of popliteal artery

7. Applied anatomy

 Popliteal artery is one of the arteries commonly used for peripheral pulsation.  Weakening or loss of the popliteal pulse is a sign of a femoral artery obstruction.  The blood pressure in the lower limb is recorded by the auscultation of the popliteal artery.  In atherosclerosis of popliteal artery, the graft can be tried from the lower part of popliteal artery as it is patent.  A common site of atheromatous occlusion is at the beginning of the popliteal artery near the adductor hiatus,  In coarctation of the aorta, the popliteal pressure is lower than the brachial pressure.

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B. Cutaneous branches arise either directly from the popliteal artery, or indirectly from its muscular branches. There are three superficial sural arteries. The central or median vessel is largest and most constant. It is sometimes named the sural cutaneous artery. It is given off close to the distal angle of the fossa. It passes distally in the groove marking the junction of the two heads of the gastrocnemius. It is a companion of the short saphenous vein. C. Genicular branches are five in number a. Two superior, b. Two inferior, and c. Middle. D. Terminal branches are two. They are a. Anterior tibial artery b. Posterior tibial artery

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 Abnormal localised dilation of an arterial wall is called aneurysm. The popliteal artery is more prone to aneurysm than any other arteries of the body. Pressure of the aneurysm on the  Vein may cause venous thrombosis and peripheral oedema.  Tibial nerve may cause severe pain in the leg. The artery lies deep to the tibial nerve; an aneurysm may stretch the nerve or compress its blood supply (vasa vasorum). The pain is referred to the skin overlying the medial aspect of the calf, ankle or foot.  True aneurysm means involvement of all the three constituents of the arterial wall, i.e. adventitia, media and the intima.  In operation of aneurysm of popliteal artery, it is ligated in the adductor canal.  The popliteal artery is exposed by  Deep dissection in the midline within the popliteal fossa. The care is taken not to injure the more superficial vein and nerve. OLA-23 Root value of tibial nerve

Ventral divisions of ventral rami of L4, L5, S1, S2, S3 OLA-24 Enumerate the terminal branches of tibial nerve

1. Medial plantar nerve, and 2. Lateral plantar nerve.

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OLA-25 Enumerate the branches of tibial nerve in popliteal fossa

Branches of tibial nerve in popliteal fossa are 1. Medial head of gastrocnemius, 2. Lateral head of gastrocnemius, 3. Plantaris, 4. Soleus, and 5. Popliteus. LAQ-9

Describe the tibial nerve under following heads 1. Root value, 2. Course and relations, 3. Branches, and 4. Applied anatomy

Introduction: It is one of the two terminal branches of sciatic nerve given at the superior angle of popliteal fossa. It is a larger branch and supplies all the muscles of back of thigh, leg and foot. 1. Root value: Ventral divisions of ventral rami of L4, L5, S1, S2, S3. 2. Course and relations

Popliteal Fossa

E. F. G. H.

It lies superficial or posterior to the popliteal vessels. It extends from the superior angle to the inferior angle of the popliteal fossa. In the popliteal fossa, it drops like plumb from superior angle to inferior angle. The relations of tibial nerve with popliteal vessels in the popliteal fossa. a. At superior angle, tibial nerve is most lateral. b. In the middle, the nerve is most superficial. c. At the inferior angle, the nerve is most medial. Distal to popliteal fossa it passes anterior to the soleus. It is the nerve of the posterior compartment of leg. It descends with the posterior tibial vessels to lie between the heel and the medial malleolus. It ends deep to the flexor retinaculum by dividing into the medial and lateral plantar nerves (Fig. 16.3A and B).

3. Branches (Fig. 16.7) A. Collateral branches a. Articular: Three genicular or articular branches arise in the upper part of the popliteal fossa. They are I. Superior medial genicular nerve. It lies above the medial condyle of femur, deep to the muscles. II. Middle genicular nerve. It pierces the posterior part of the capsule of the knee joint to supply structures in the intercondylar notch of femur. III. Inferior medial genicular nerve. It lies along the upper border of popliteus and reaches medial condyle of tibia. b. Cutaneous nerve is called sural nerve. It originates in the middle of the fossa and leaves it at the inferior angle. It supplies the skin of I. Lower half of back of leg, and II. Lateral border of the foot till the tip of little toe. c. Muscular branches arise in the distal part of the fossa for the I. Lateral and medial heads of gastrocnemius, II. Soleus, III. Plantaris, and IV. Popliteus. V. Nerve to the popliteus: Peculiarities of the nerve to popliteus: • It crosses the popliteal vein and artery from medial to lateral. • It runs downwards. • It winds inferior border and runs its deep (anterior) surface. • In addition to the popliteus, the nerve also supplies the – Tibialis posterior, – Superior tibiofibular joint, – Medullary cavity of tibia,

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A. B. C. D.

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– Interosseous membrane, and – Inferior tibiofibular joint. B. Terminal branches a. Medial plantar, and b. Lateral plantar

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Fig. 16.7: Right tibial nerve and its relations to the popliteal vessels

4. Applied anatomy

 Most of the muscular branches of tibial nerve arise from its lateral side except to the medial head of gastrocnemius. So, the medial side is called side of safety and lateral side is called side of danger. The tibial nerve is always approached from medial side to avoid the rupture to the muscular branches of the tibial nerve (Fig. 16.8).

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Fig. 16.8: Right tibial nerve showing side of safety and side of danger

OLA-26 Root value of common peroneal nerve

Dorsal divisions of ventral rami of L4, L5, S1, S2. OLA-27 Branches of common peroneal nerve in the fossa

Branches of common peroneal nerve in the popliteal fossa. 1. Muscular: Short head of biceps femoris 2. Cutaneous: A. Lateral cutaneous nerve of calf, and B. Sural communicating nerve.

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 Damage to tibial nerve causes motor and sensory loss.  Muscles paralysed are – Superficial and deep muscles of calf. – Intrinsic muscles of sole.  Sensory loss – Loss of sensation on whole of sole of foot. – Plantar aspect of digits and nail beds on dorsum of foot.  Pressure of the aneurysm of popliteal artery on tibial nerve may cause severe pain in the leg.  Entrapment and compression of the tibial nerve (tarsal tunnel syndrome) occurs due to oedema and tightness in the ankle.  The pain in the heel may result from compression of tibial nerve by flexor retinaculum.

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3. Articular A. Superior lateral genicular, B. Inferior lateral genicular, and C. Recurrent genicular. 4. Terminal A. Deep peroneal, and B. Superficial peroneal. SN-13

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Common Peroneal Nerve

Introduction: It is one of the two terminal branches of sciatic nerve given at the superior angle of popliteal fossa. It is a smaller branch. 1. Root value: Dorsal division of ventral rami of L4, L5, S1, S2 segments of spinal cord. 2. Course and relations A. It lies in the upper lateral part of popliteal fossa. B. It runs along the medial border of biceps femoris muscle. C. It winds around neck of fibula (postaxial bone). D. Then it lies in the substance of peroneus longus muscle. 3. Branches A. Muscular branch: Short head of biceps. B. Cutaneous: Lateral cutaneous nerve of calf C. Vascular: Sural communicating D. Articular a. Superior lateral genicular, b. Inferior lateral genicular, and c. Recurrent genicular. E. Terminal a. Superficial branch supplies muscles of lateral compartment of leg. They include I. Peroneus longus II. Peroneus brevis b. Deep branch supplies dorsiflexors (extensors) of the ankle joint. They include I. Tibialis anterior II. Extensor hallucis longus III. Extensor digitorum longus IV. Peroneus tertius. 4. Applied anatomy

 It is the most commonly injured nerve.  It is injured due to

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 Fracture of neck of fibula,  ‘Lathi injury’ on the lateral side of knee joint, or  Plaster on the leg: The nerve gets compressed between hard plaster and neck of fibula.  Effects of injury  Motor loss: Foot drop due to paralysis of dorsiflexors and evertors of foot.  Sensory loss • Back of leg, • Lateral side of leg, and • Most of dorsum of foot. Foot Drop

1. Definition: It is due to injury to common peroneal nerve. It leads to paralysis of dorsiflexion and eversion of foot resulting in “foot drop”. 2. Causes A. Fracture of neck of fibula, B. ‘Lathi injury' on the lateral side of knee joint, or C. Plaster on the leg: The nerve gets compressed between hard plaster and neck of fibula. 3. Effects of injury A. Motor loss: Foot drop due to paralysis of dorsiflexors and evertors of foot. B. Sensory loss I. Back of leg, II. Lateral side of leg, and III. Most of dorsum of foot. 4. Paralysis of muscles A. Tibialis anterior, B. Extensor hallucis longus, and C. Peroneus tertius. 5. Position of the foot A. It is plantar flexed. B. Inversion and plantar flexion are normal and ankle jerk is intact SN-15

Popliteus

(Pop—ham, posterior aspect of knee) Introduction: It is a flat, lar muscle present in the floor of lower part of popliteal fossa. 1. Features A. It is deep muscle of posterior compartment of leg. B. It is key muscle of knee joint.

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2. Peculiarities A. It has tendinous proximal attachment and fleshy distal attachment. B. The proximal attachment is intracapsular and extrasynovial. C. It forms the floor of lower part of popliteal fossa. 3. Attachments (Fig. 16.9) A. Proximal attachment: It arises from a. Popliteal groove present on the lateral surface of the lateral condyle of femur. Popliteal groove has anterior and posterior parts. The popliteus takes origin from the anterior part of the groove. The popliteus tendon occupies posterior part of the groove in full flexion of the knee. The popliteal tendon is about 1 length. Collagenous bands connect the tendon of popliteus to the arcuate popliteal ligament. b. Arcuate ligament c. The outer margin of lateral meniscus of the knee joint.

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3 Fig. 16.9: Posterior view of right knee joint showing popliteus muscle

B. Distal attachment a. Posterior surface of tibia into medial 2/3rd of the the soleal line. b. Fascia covering it.

triangular area above

4. Nerve supply : It is supplied by a nerve to popliteus, a branch of tibial nerve (L4, L5, S1) (Fig. 16.10). 5. Relations A. Anterior: Lateral condyle of tibia B. Posterior a. Strong fascia, an extension of semimembranosus from the insertion.

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Fig. 16.10: Course, relations and distributions of the nerve to popliteus on right side.

B.

PP lm PP Popliteus, Pulls, lateral meniscus Posteriorly, and Prevents it from being trapped at the beginning of the flexion.

C. In standing with the knee partly flexed, the popliteus contracts and helps the posterior cruciate ligament (PCL) to prevent anterior displacement of the femur. Box 16.2 Note: To summarize, the popliteus is a lateral rotator of the femur on the tibia and simultaneously a retractor of the lateral meniscus. Its femoral tendon is attached at the axis of movement of the hinge joint of the knee; consequently, it is not even a weak flexor of the knee joint. 7. Applied anatomy : Injury to tibial nerve may result weakness of unlocking of

knee joint.

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b. Popliteal vessels, and c. Tibial nerve. 6. Actions A. It unlocks the knee in initial phase of flexion, i.e. medial rotation of tibia on the fixed femur (when the foot is off the ground), or a. Lateral rotation of femur on fixed tibia (when the foot is on the ground). b. Flexes the knee joint.

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SAQ-15 Name the branches of profunda femoris artery

Branches of the profunda femoris artery are (Fig. 17.1) 1. Medial circumflex femoral artery. It gives branches A. Ascending branch, and B. Transverse branch. 2. Lateral circumflex femoral artery. It gives branches A. Ascending branch, B. Transverse branch, and C. Descending branch. 3. Perforating arteries. They are 4 in number.

Fig. 17.1: Branches of right profunda femoris artery 154

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OLA-28 Enumerate the hamstring muscles

1. 2. 3. 4.

Semimembranosus, Semitendinosus, Ischial fibres of adductor magnus, and Long head of biceps.

SN-16

Hamstring Muscles

(Ham—posterior aspect of lower part of thigh and knee; string—thread or rope-like). Introduction: These are string-like muscles present on the posterior aspect of thigh. 1. Particulars: They are A. Semimembranosus a. The upper part of the muscle is membrane-like and measures about 15 cm in length, b. It arises from smooth facet present on the lateral part of ischial tuberosity, and c. The tendon is rounded on its lateral margin and sharp at its medial margin. It .

B. Semitendinosus: The lower part of the muscle is tendon like. It arises from medial facet of ischial tuberosity. C. Biceps femoris: It has two heads. The ischial head is a part of hamstring muscle. D. Ischial fibres of adductor magnus. 2. Features A. They are also called muscles of posterior or flexor compartment of thigh. B. The hamstring muscles span the femur but gain no attachment to it. 3. Characters A. All the muscles arise from ischial tuberosity. They get inserted into one of the bones of leg (either tibia or fibula). The two “semi” muscles are inserted medially and the two heads of biceps laterally. When the knee is flexed the alternate contraction of these muscles produces rotation at the knee joint. The “semi” muscles are medial rotators; the biceps are lateral rotator of the tibia on the femur. B. They are supplied by the tibial division of sciatic nerve (L4, L5, S1, S2, S3). C. They are essentially flexors of the knee joint but they have extensor action of the hip joint. 4. Blood supply A. Perforating branches of profunda femoris artery. B. Upper part of hamstring is supplied by inferior gluteal artery branch of anterior division of internal iliac artery. C. Popliteal artery.

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resembles hollow ground razor

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156

5. Testing of muscles A. Position of subject: Prone position with knee extended. B. Activity: The subject is asked to flex the knee against resistance. C. Feel posterior aspect of thigh. 6. Applied anatomy

 The extension of hip and flexion of the knee is essential for runners. These muscles are liable for overstrain.  The professional runners are prone to a painful condition known as pulled hamstring. The attachment of hamstrings from the ischial tuberosity is torn.  Muscle injuries may occur as a result of direct trauma or as part of an over use syndrome. Muscle injuries may occur as a minor muscle tear. This is demonstrated as a focal area of fluid within the muscle. Hamstring muscles are usually torn in the thigh.  If hamstring muscles are paralyzed, the patient tends to fall forward because the gluteus maximus muscle cannot maintain the necessary tone to stand upright.  In old days, the soldiers used to slash the back of the knees of horses of their opponents. This cuts the tendons of hamstring muscles. This brings the horse and its rider down.  People also used to cut the hamstring tendons of soldiers so that they could not run. This was termed “hamstringing” the enemy.

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OLA-29 What is the root value of sciatic nerve?

Sciatic nerve (ventral and dorsal divisions of ventral rami of L4, L5, S1, S2, S3) LAQ-10 Describe the sciatic nerve under following heads 1. Root value, 2. Peculiarities, 3. Course and relations, 4. Distribution, 5. Applied anatomy

Introduction: The sciatic nerve is the largest nerve in the body and is the continuation of the main part of the sacral plexus. The rami converge at the inferior border of the piriformis to form the sciatic nerve, a thick, flattened band. The sciatic nerve is the most lateral structure emerging through the greater sciatic foramen. 1. Root value: It arises from ventral divisions of ventral rami of L4, L5, S1, S2, S3 and dorsal divisions of ventral rami of L4, L5, S1, S2, 2. Peculiarities A. It is thickest nerve in the body, 2 cm wide. It is equal to the little finger, Fig.

.

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B. The sciatic nerve supplies the posterior aspect of thigh and all other structures below the knee EXCEPT the skin of the medial leg, which is supplied by the saphenous nerve, a branch of the femoral nerve. C. Sciatic nerve is accompanied by a thin artery, the sciatic artery, which is part of the axial artery of the lower limb. 3. Course and relations (Fig. 17.2A and B) A. Course: The course and relations of the sciatic nerve is as follows a. In pelvis: It lies in front of piriformis. b. It enters gluteal region through greater sciatic foramen (below piriformis). It passes between ischial tuberosity and greater trochanter. It emerges from lower border of gluteus maximus and passes downward deep to the long head of biceps. B. Relations a. Superficial: Gluteus maximus. b. Superficial and medial: Posterior cutaneous nerve of thigh c. Deep I. Body of ischium, II. Ascending branch of medial circumflex femoral artery (branch of profunda femoris), III. Tendon of obturator internus with the gemelli, V. Deep to above structures: Capsule of the hip joint. d. Medial I. Inferior gluteal vessels branch of anterior division of internal iliac artery, II. Inferior gluteal nerve (L5, S1, S2), III. Pudendal vessels branch/tributary of anterior division of internal iliac artery IV. Pudendal nerve (S2, S3, S4), and V. Posterior cutaneous nerve of thigh (S1, S2, S3). C. Branches a. Collateral branches I. Tibial division of sciatic nerve supplies hamstring muscles, namely i. Semimembranosus, ii. Semitendinosus, iii. Ischial fibres of adductor magnus, and iv. Long head of biceps. II. Common peroneal branch supplies short head of biceps, and III. Articular branch to hip joint.

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IV. Nerve to quadratus femoris (L4, L5 and S1), and

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3 A

B

Fig. 17.2A and B: (A) Relations of sciatic nerve in gluteal region; (B) Course and relations of right sciatic nerve

b. Terminal branches: At the junction of upper 2/3rd and lower 1/3rd, the sciatic nerve divides into tibial and common peroneal nerves. 4. Distribution: The sciatic nerve supplies no structures in the gluteal region. It divides into A. Tibial, and B. Common peroneal nerve. A. The tibial part of sciatic nerve supplies I. Medial plantar nerve and

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II. Lateral plantar nerve

6. Applied anatomy

 A pain in the buttock may result from compression of the sciatic nerve by the piriformis muscle (piriformis syndrome). Individuals involved in sports that

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i. The medial plantar nerve supplies all the muscles present on the medial side of foot except adductor hallucis. ii. The lateral plantar nerve supplies all the muscles present on the lateral side of foot and adductor hallucis. Tibial nerve gives articular branches to all joints of the lower limb. B. Common peroneal nerve a. Root value: Dorsal divisions of ventral rami of L4, L5, S1, and S2. b. Course: This is one of the smaller terminal branches of the sciatic nerve. It lies in the same superficial plane as the tibial nerve. It extends from the superior angle of the popliteal fossa to the lateral angle. It runs along the medial border of the biceps femoris. It winds round the posterolateral aspect of the neck of the fibula. It pierces the peroneus longus. c. Branches I. Collateral II. Cutaneous branches are two. They are i. Lateral cutaneous nerve of the calf descends to supply the skin of the upper 2/3rd of the lateral side of the leg, and ii. Sural communicating nerve arises in the upper part of the fossa. It runs on the posterolateral aspect of calf and joins the sural nerve. III. Articular branches • Superior lateral genicular nerve accompanies the artery of the same name and lies above the lateral femoral condyle, • Inferior lateral genicular nerve also runs with the artery of the same name to the lateral aspect of knee joint above the head of fibula, and • Recurrent genicular nerve arises where common peroneal nerve divides into superficial and deep peroneal nerves. It ascends anterior to the knee joint and supplies tibialis anterior muscle in addition to the knee joint. • Muscular branches do not arise from this nerve. However, it may give a branch to the short head of biceps femoris. IV. Terminal branches i. Superficial peroneal nerve, and ii. Deep peroneal nerve. 5. Blood supply: Arterial supply of sciatic nerve is by artery of sciatic nerve. It is a branch of inferior gluteal artery. It represents the axis artery in gluteal region and may at times be quite large. It is companion artery of the sciatic nerve (arteria comitans nervi ischiadici). It is a long branch that descends for some distance with the sciatic nerve. It anastomoses with the perforating branches of the profunda femoris artery.

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require excessive use of the gluteal muscles (e.g. ice skaters, cyclists, and rock climbers) and women are more likely to develop this syndrome. Sciatica: It is due to compression and irritation of nerve roots of sciatic nerve. The patient gets shooting pain along the cutaneous distribution of the sciatic nerve. The pain begins in the gluteal region and radiates along the back of thigh, posterior and lateral side of the leg and to the dorsum of foot. Sciatica may be caused by  Injury to the sacral plexus in the pelvis, and  Injury to the nerves. Bony outgrowths or tumours. The pain affects the back of the thigh and outer side of the leg. “Sciatic nerve block” is done by injecting an anaesthetic agent few cm below the midpoint of the line joining posterior superior iliac spine and upper border of greater trochanter. Complete section of the sciatic nerve is uncommon. When this occurs, the leg is useless because extension of the hip is impaired, as is flexion of the leg. All ankle and foot movements are also lost. Incomplete section of the sciatic nerve (e.g. from stab wounds) may also involve the inferior gluteal and/or the posterior femoral cutaneous nerve. The deep intramuscular injection in the lower medial quadrant of gluteal region causes injury to the sciatic nerve. In a sarcoma of medial compartment of the thigh, resection of the adductor magnus may be required. The sciatic nerve lies directly behind the medial portion of the adductor magnus. Care should be taken to prevent injury to sciatic nerve. Posterior dislocations of hip joint may cause serious injury to sciatic nerve. Injury to the nerve paralyses muscles of the back of the thigh (hamstrings), and all muscles of the leg and foot. The foot hangs downwards (by its own weight): The condition is called foot drop. Foot drop is also caused by injury to the common peroneal nerve. There is sensory loss over the greater part of the leg and foot.

OLA-30 Name the muscles of posterior compartment of thigh

Muscles of the posterior compartment of thigh are 1. Semimembranosus, 2. Semitendinosus, 3. Ischial fibres of adductor magnus, and 4. Short head and long head of biceps.

18 Front, Lateral and Medial Sides of Leg and Dorsum of Foot OLA-31 Name the muscles supplied by superficial peroneal nerve

1. Peroneus longus, and 2. Peroneus brevis. OLA-32 Enumerate muscles of anterior compartment of leg

1. 2. 3. 4.

Tibialis anterior, Extensor hallucis longus, Extensor digitorum longus, and Peroneus tertius.

OLA-33 Enumerate muscles of lateral compartment of leg

1. Peroneus longus, and 2. Peroneus brevis. OLA-34 Enumerate muscles of posterior superficial compartment of leg

1. Medial head of gastrocnemius, 2. Lateral head of gastrocnemius, 3. Soleus, and 4. Plantaris. OLA-35 Enumerate muscles of posterior deep compartment of leg

1. Popliteus, 2. Flexor digitorum longus, 3. Flexor hallucis longus, and 4. Tibialis posterior. 161

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OLA-36 Name the muscles supplied by deep peroneal nerve

1. Muscles of the anterior compartment of the leg A. Tibialis anterior, B. Extensor hallucis longus, C. Extensor digitorum longus, and D. Peroneus tertius. 2. Muscle of the dorsum of the foot: Extensor digitorum brevis OLA-37 Name the branches of dorsalis pedis artery

1. 2. 3. 4.

Lateral tarsal artery, Medial tarsal branches, Arcuate artery, and Dorsal metatarsal arteries: They are 4 in number. Each artery divides into 2 dorsal digital arteries.

SN-17

Peroneus Longus Muscle

Introduction: It is superficial muscle in the lateral compartment of leg. 1. Proximal attachments A. Head of the fibula,

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B. Upper 1/3rd, and C. Lateral surface of the shaft of the fibula (upper 2/3rd). 2. Distal attachments A. Lateral side of the base of the 1st metatarsal bone, and B. Adjoining part of the medial cuneiform bone. The tendon changes its direction below the lateral malleolus and again on the cuboid bone. 3. Peculiarities A. A sesamoid bone is present in the tendon. B. It continues as lateral collateral ligament. 4. Actions A. Evertor of foot especially when foot is off the ground. B. Maintains lateral longitudinal and transverse arch of the foot. C. Peroneus longus and tibialis anterior are inserted into the same medial cuneiform bone, the two together form a ‘stirrup’ beneath the middle of the sole. D. The presence of the sling keeps the middle of foot pulled up and prevents flattening of its arches. E. The peroneus longus and brevis come into play in extreme plantar flexion. 5. Nerve supply: Superficial peroneal nerve (L4, L5, S1, S2)

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6. Applied anatomy

 Paralysis of peroneus brevis and peroneus longus occurs due to injury to superficial peroneal nerve.  The foot cannot be everted at subtalar joint. Dorsalis Pedis Artery

Introduction: It is also called the dorsal artery of the foot. It is the chief artery of dorsum of foot. 1. Origin: It is the continuation of anterior tibial artery in front of ankle joint, distal to inferior extensor retinaculum. 2. Termination: It continues as deep plantar or perforating branch. In the sole, it completes the plantar arch by joining the lateral plantar artery. 3. Extent: It extends from distal end of inferior extensor retinaculum to proximal end of 1st intermetatarsal space. 4. Features A. This is the chief palpable artery of the dorsum of the foot. B. It behaves like the radial artery in the hand. Its main branch ends between the 1st and 2nd metatarsal bones. It reaches the plantar surface of the foot. It becomes the main contributor to the plantar (deep plantar) arch. 5. Course (Fig. 18.1) A. It begins in front of the ankle joint between two malleoli (medial and lateral). B. It passes along the medial side of the dorsum of the foot. C. It reaches the proximal end of 1st intermetatarsal space. Here it pierces 1st dorsal interosseous muscle.

Fig. 18.1: Course and branches of right dorsalis pedis artery

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SN-18

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164

6. Relations A. Superficial: The artery is very superficial. The extensor hallucis brevis is the only structure that separates it from the skin, superficial fascia and deep fascia. B. Deep a. Capsular ligament of the ankle joint. b. The tarsal bones from posterior to anterior are I. Talus, II. Navicular, and III. Intermediate cuneiform bones and the ligaments connecting them. C. Medial: Extensor hallucis longus D. Lateral a. 1st tendon of the extensor digitorum longus. b. Medial terminal branch of the deep peroneal nerve. 7. Branches A. Lateral tarsal artery, B. Medial tarsal branches, C. Arcuate artery, and D. Dorsal metatarsal arteries.

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8. Applied anatomy

 Dorsalis pedis artery is superficial and its pulsations are felt.  It is often palpated in patients suffering from vaso-occlusive diseases of the lower limb, viz. Buerger’s disease.  The pulsations help to  Determine the level of amputation of leg in case of gangrene of toes.  Assess peripheral circulation.  The artery is rarely ligated. OLA-38 Cutaneous nerve supply of dorsum of foot

1. Skin of the dorsum of the foot is supplied by medial and lateral branches except A. Lateral border, supplied by sural nerve. B. Medial border up to the base of the great toe, supplied by the saphenous nerve C. Cleft between the 1st and 2nd toes, supplied by the deep peroneal nerve.

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Fig. 18.2: Cutaneous nerves on the front of the leg and dorsum of right foot

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19 Back of Leg

SAQ-16 Tibialis posterior muscle

1. Proximal attachments (Fig. 19.1) A. Upper 2/3rd of lateral part of posterior surface of tibia below the soleal line. B. Posterior surface of a. Fibula in front of the medial crest, and b. Interosseous membrane.

Fig. 19.1: Posterior surface of bones of leg and foot showing attachments of tibialis posterior muscle

2. Distal attachments A. Tuberosity of navicular bone and other tarsal bones except talus. B. It is extended into 2nd, 3rd and 4th metatarsal bones at their bases. 166

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3. Nerve supply : Tibial nerve (ventral division of ventral rami of L4, L5, S1, S2, S3) segments of spinal cord. 4. Action A. With gastrocnemius and soleus, it brings flexion of foot which acts at ankle joint. B. With tibialis anterior, it brings inversion of foot which acts at subtalar joint, and C. It supports medial longitudinal arch of foot. OLA-39 Give the attachments and actions of soleus

1. Proximal attachments (Fig. 19.2): It arises from A. The back of head of fibula and upper l/4th of posterior surface of fibula, B. Soleal line and middle l/3rd of medial border of shaft of tibia, C. Deep transverse fascia of leg, and D. Soleal arch which stretches between tibia and fibula (Fig. 19.2).

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Fig. 19.2: Origin and insertion of right soleus muscle

2. Distal attachments: The tendon of soleus fuses with tendon of gastrocnemius to form tendo calcaneus. It is inserted into middle l/3rd of posterior surface of calcaneus. 3. Action A. When the knee is flexed, action of gastrocnemius becomes ineffective. Hence soleus is the main plantar flexor of flexed knee. B. In standing position, it steadies the leg. C. In walking, it acts as a bottom or 1st gear and so it overcomes the inertia of body weight.

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SN-19

Soleus

(Soleus is shaped like the sole of a boot or flat fish (sole fish that reclines on sea floor).) 1. Introduction: It is multipennate superficial muscle of posterior compartment of leg. It is situated deep to the gastrocnemius. 2. Features A. The large size of the gastrosoleus is a human character. It is directly related to the adoption of an erect posture. It is the feature of the bipedal gait of man. B. Morphologically, it corresponds with the flexor digitorum superficialis muscle of the forearm. C. The soleus is located deep to the gastrocnemius and is considered to be the “workhorse” (A horse used for work on a farm) of plantar flexion. D. The gastrocnemius and the soleus are together called the triceps surae which forms the bulging of the calf. E. It forms the 2nd layer of posterior compartment of leg. F. The flexor digitorum brevis is detached distal part of the soleus. 3. Peculiarities

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A. The soleus contains a rich plexus of small veins. The contraction of the soleus squeezes the vessels and facilitates venous return from the lower extremity. Hence it is often called peripheral heart. The calf muscles collectively work as a venous pump. During relaxed state of the muscles, the blood is sucked from the superficial to the deep veins through the perforators. B. The superficial veins of leg (e.g. saphenous veins) drain into soleal sinuses through perforating veins. The soleal sinuses empty segmentally into deep veins of the leg (e.g. posterior tibial and peroneal veins). 4. Attachments: It arises entirely below knee. A. Proximal attachment: It has a continuous proximal attachment in the shape of an inverted U. It has two heads. a. Tibial head I. Soleal line of the tibia, and II. Middle 1/3rd of the medial border of tibia. III. Intermuscular septum b. Fibular head: The posterior surfaces of the head of the fibula and of the upper 1/3rd of its shaft; c. These two heads are united by tendinous arch. It represents the upper part of the transverse intermuscular septum and extends between the tibia and the fibula. The additional fibres arise from this arch. B. Distal attachments: The tendon of soleus fuses with tendon of gastrocnemius and form tendo calcaneus. It is inserted into middle 1/3rd of posterior surface of calcaneus. The tendo calcaneus is thickest and strongest tendon in the body (Refer to Fig. 19.2).

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5. Relations: The popliteal artery and tibial nerve leave the popliteal fossa through proximal attachment of soleus. This bifurcates into its terminal branches, namely the anterior and posterior tibial arteries. A. Superficial a. Gastrocnemius, and b. Plantaris. B. Deep a. Flexor digitorum longus, b. Flexor hallucis longus, c. Tibialis posterior, d. Posterior tibial vessels, and e. Tibial nerve. C. Structures passing deep to soleal arch are popliteal vessels. 6. Blood supply: Sural branch of popliteal artery. 7. Nerve supply : Tibial nerve. The nerves to the soleus, carrying fibres from spinal cord segments L5 to S2, are double. 8. Action

9. Applied anatomy

 Thrombosis or the veins of the soleus muscle give rise to mild pain in the calf. However, deep vein thrombosis (DVT) also occurs with no signs or symptoms. Dislodged thrombus causes pulmonary embolism which is often fatal. Hourly stretching prevents the thrombosis.  The veins draining the soleus do not have valve. These resemble dural venous sinuses present in the cranium. These are called soleal sinuses. The tendo calcaneus is frequently strained at the start of a short race due to abrupt take-off. It may rupture when it is stressed. The complete rupture of this tendon causes abrupt pain in the posterior aspect of the leg and person stumbles with pain. Consequently, he is unable to use his limb and thus cannot walk. He develops lump due to shortening of the gastrocnemius and soleus muscles.

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A. The soleus and gastrocnemius bring plantar flexion at ankle joint. B. Strong plantar flexion of ankle joint. When the knees flexed, the soleus is the main muscle for plantar flexion at ankle because the action of gastrocnemius becomes ineffective. C. It steadies leg in standing position. D. In walking, it acts as a bottom or 1st gear and so it overcomes the inertia of body weight. It acts as a propelling force in walking. E. Muscle injuries may occur as a result of direct trauma or as part of an overuse syndrome. Tears of the muscles below the knee typically occur within the soleus muscle.

20 Sole of Foot

OLA-40 Name the muscles of 1st layer of sole

They are tendons of 1. Abductor hallucis, 2. Abductor digiti minimi, and 3. Flexor digitorum brevis. OLA-41 Name the muscles of 2nd layer of sole

They are tendons of 1. Flexor hallucis longus, 2. Flexor digitorum longus, 3. Flexor accessorius, and 4. Lumbricals. OLA-42 Name the muscles of 3rd layer of sole

They are tendons of 1. Adductor hallucis, 2. Flexor hallucis brevis, and 3. Flexor digiti minimi brevis. OLA-43 Mention the structures in the 4th layer of sole of foot.

The structures in the 4th layer of sole of foot Tibialis posterior, Palmar and dorsal interossei, and Peroneus longus. 170

TIP

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Muscles supplied by lateral plantar nerve

These are branches from main trunk and from terminal branches (Figs 20.1 and 20.2). 1. Branches from main trunk A. Flexor digitorum accessories, and B. Abductor digiti minimi.

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2. Terminal branches A. Superficial branch a. Lateral branch I. Flexor digiti minimi brevis, II. 3rd plantar interossei, and III. 4th dorsal interossei. b. Medial branch is cutaneous supplies 4th intercleft. B. Deep branches supply following 9 muscles a. Three lumbricals I. 2nd, II. Two plantar interossei II. 3rd, and i. 1st, and III. 4th lumbrical. ii. 2nd plantar interossei. b. Five interossei c. Adductor hallucis. I. Three dorsal interossei: i. 1st, ii. 2nd, and iii. 3rd

Fig. 20.1: Right lateral plantar nerve with its branches

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Fig. 20.2: Branches of lateral plantar nerve

OLA-44 Muscles supplied by medial plantar nerve

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Medial plantar nerve supplies four muscles of the sole. They can be grouped as muscles from 1. First layer A. Abductor hallucis, and B. Flexor digitorum brevis. 2. 2nd layer: 1st lumbrical. 3. 3rd layer: Flexor hallucis brevis. OLA-45 Nerve supply of lumbricals of sole

1. 1st lumbrical is supplied by medial plantar nerve, and 2. 2nd, 3rd, 4th lumbricals are supplied by deep branch of lateral plantar nerve. SAQ-17 Actions of dorsal interossei of foot

1. Axis of movement: Longitudinal axis of the foot lies along the 2nd metatarsal bone and the phalanges of the 2nd toe. 2. The actions of the interossei of the foot are indicated by the formula

“DAB”

A. Dorsal interossei are abductors. They abduct away from the axis line. B. First and 2nd interossei cause medial and lateral abduction of second toe. Third and 4th are abductors of 3rd and 4th toes.

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SAQ-18 Actions of plantar interossei of foot

1. Axis of movement: Longitudinal axis of the foot lies along the 2nd metatarsal bone and the phalanges of the 2nd toe. 2. The actions of the interossei of the foot are indicated by the formula

“PAD”

A. The plantar interossei are adducting muscles. They adduct towards the 2nd toe. B. The 1st toe has its own adductors. (Oblique and transverse heads of adductor hallucis). The lateral three toes require adductors. C. 1st, 2nd and 3rd plantar interossei arise only from the metatarsal bone of its own digit. They are inserted by tendons into the medial sides of the 3rd, 4th and 5th digits. SN-21

Plantar aponeurosis

Introduction: It is a thickened central part of deep fascia. 1. Formation: It is formed by longitudinal displayed compact bundles of collagen fibres. 2. Features: It consists largely white fibrous connective tissue. They are glistening in nature. 3. Parts: Deep fascia in the sole has following parts

D. Shape: It is lar in shape having the base and apex. a. The proximal part is apex and is attached to medial tubercle of calcaneum. b. The distal part is base and divides opposite the head of metatarsal bones into 5 slips or processes which are connected by transverse fibres. There are 5 gaps in the processes. The digital vessels, nerves and lumbricals pass through it. c. Each slip or process divides into I. Superficial part: It is attached to transverse sulcus of the skin. It is present at the toes of foot. II. Deep part: It splits into two parts and transmits the flexor tendons. They are attached to i. Transverse metatarsal ligament, ii. Fibrous sheaths of flexor tendons, and iii. Lateral and medial borders of proximal and middle phalanx.

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A. Lateral part (calcaneometatarsal ligament): It covers the abductor digiti minimi. It extends from lateral tubercle of calcaneum to the base of proximal phalanx of 5th toe. B. Medial part: It covers abductor hallucis. It extends from lateral tubercle of calcaneum to the base of proximal phalanx of great toe. Both lateral and medial parts are thin. C. Central part: It is the thickest part and most prominent part and in reality, it is the plantar aponeurosis. These medial and lateral parts are, sometimes, called plantar fascia.

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4. Relations A. Superficial a. Thick heavily keratinized skin, and b. Cutaneous branches/tributaries of medial plantar vessels and nerves. B. Deep a. Abductor hallucis, b. Flexor digitorum brevis, and c. Abductor digiti minimi. 5. Structures piercing: Cutaneous branches of the medial and lateral plantar nerves penetrate the aponeurosis to supply the overlying skin and fascia. 6. Morphology: It is continuation of the plantaris muscle and homologous to palmar aponeurosis. 7. Functions A. It maintains the stability of medial and lateral longitudinal arches. B. It acts as tie beam which prevents the separation of the anterior and the posterior pillars underweight on the top. C. It provides attachment to superficial plantar muscles. D. It protects plantar vessels and nerves.

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E. The skin ligaments also anchor the skin to the underlying deep fascia (plantar aponeurosis), improving the “grip” of the sole. F. It gives proximal attachments to muscles of the 1st layer of the sole. G. It bears greater stress of the longitudinal arches of the foot. H. It acts like a superficial ligament. 8. Applied anatomy

 Plantar fasciitis  Definition: Inflammation of the aponeurosis is called plantar fasciitis.  Infection of the sole  Collection of pus under plantar aponeurosis is well localized.  Normally, it cannot come out through aponeurosis, because of its tough nature.  The condition is very painful and causes more damages to the structures underneath.  High arched foot (pes cavus) occurs when the longitudinal arch becomes unduly elevated. It is due to  Shortening of plantar aponeurosis, or  Contracture of the intrinsic muscles of the foot.

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Comparison between the plantar and palmar aponeurosis Table 20.1: Comparison between the plantar and palmar aponeurosis

Particulars

Plantar aponeurosis

Palmar aponeurosis

• Strength

• Strong

• Comparatively weak

• Proximal attachment

• Calcaneum

• Flexor retinaculum

• Functions

• Protects deeper structures • Support the body weight

• Protect deeper structures

• Division

• Sole is divided into three compartments by two intramuscular septa

• Palm is divided into 4 compartments

• Subdivision

• Only central part divides into 5 slips

• Divides into 4 slips

• Muscles arising

• Abductor hallucis, • Flexor digitorum brevis, and • Abductor digiti minimi.

• Palmaris brevis

Layers of sole

Introduction: The sole of the foot contains long tendons and a number of small muscles which are arranged in four layers. Unlike the hand, the big toe is prevented from coming into contact with the other toes. However, the toes do have the capability to be used for grasping. This can be seen in people born without arms, who can learn to write, draw and manipulate objects with their feet. 1. Muscles of each layer (Fig. 20.3) A. 1st layer or most inferior layer or superficial layer. a. Muscles I. Abductor hallucis, II. Abductor digiti minimi, and III. Flexor digitorum brevis. b. Proximal attachments: All these muscles arise from the tuberosity of the calcaneus. c. Distal attachments I. The abductor hallucis inserts on the proximal phalanx of the big toe. II. The abductor digiti minimi inserts on the proximal phalanx of the little toe. III. The flexor digitorum brevis separates into four tendons that insert onto the middle phalanges of the four lateral toes.

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SN-23

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B. 2nd layer a. Tendons of I. Flexor digitorum longus, and II. Flexor hallucis longus. b. Muscles I. Flexor accessorius i. Proximal attachment: It has two heads from the calcaneus. ii. Distal attachments: Into the tendon of the flexor digitorum longus muscle. iii. Action: Align the pull of the tendons of the flexor digitorum longus by straightening the diagonal vector of the long tendon. II. Lumbricals: 1st lumbrical is only unipennate, 2nd, 3rd and 4th lumbricals are bipennate. i. Proximal attachments: Arise from the tendons of the flexor digitorum longus muscle. ii. Distal attachments • Medial side of the proximal phalanx of the lateral four toes, and

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• Dorsal extensor hoods of the toes. C. 3rd layer: The 3rd layer of plantar muscles consists of two flexors and an adductor (with two heads), in contrast to the 1st layer, which contains two flexors and an abductor

Fig. 20.3: Layers of the right sole showing the structures

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a. Flexor hallucis brevis, b. Flexor digiti minimi brevis, and c. Adductor hallucis. D. 4th layer or uppermost layer

TIP

Tibialis posterior. Interossei: 3 plantar and 4 dorsal. Tendon of peroneus longus. 2. Nerve supply

4. Applied anatomy

 Injury to the tibial component of the sciatic nerve causes paralysis of muscles of sole of the foot. It leads to inability to stand on the toes (due to loss of plantar flexion of foot) and loss of Achilles tendon reflex.  There will be sensory loss on the sole of the foot. Trophic ulcers tend to develop in the sole of foot due to loss of sensation. OLA-46 Cutaneous nerve supply of sole of foot

1. Medial calcaneal branches of the tibial nerve supply the posterior and medial portions of the foot. 2. Branches from the A. Medial plantar nerve to the larger anteromedial portion including the medial 3½ digits, B. Lateral plantar nerve to the smaller anterolateral portion. It includes the lateral 1½ digits. C. Saphenous and sural nerves supply small areas on medial and lateral sides of the foot.

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A. Medial plantar nerve supplies 4 intrinsic muscles. (Refer to OLA-46) B. Lateral plantar nerve supplies 14 intrinsic muscles. (Refer to SN-20:1 and 2) C. Extrinsic muscles are supplied by nerve of the respective compartment of leg. a. 2nd layer I. Flexor digitorum longus II. Flexor hallucis longus—tibial nerve (L4, L5, S1, S2, S3) b. 4th layer I. Tibialis posterior—branch of nerve to popliteus (tibial nerve) (L4, L5, S1, S2, S3) II. Peroneus longus—superficial peroneal nerve (L4, L5, S1, S2) 3. Functions A. They are chiefly concerned with supporting the arches of the foot. B. Although their names would suggest control of individual toes, this function is rarely used in most people.

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Fig. 20.4: Cutaneous nerves supply of the right sole

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21 Venous and Lymphatic Drainage and Comparison of Lower and Upper Limbs SAQ-19 Venous perforators of lower limb

1. Definition: Venous perforators connect the superficial with the deep veins. 2. Number A. There are about 5 perforators along the great saphenous vein (Fig. 21.1), and B. One perforator along the small saphenous vein. 3. Features A. They are provided with valves. B. They permit flow of blood only from the superficial to the deep veins. 4. Applied anatomy : Failure of the valves gives rise to varicose veins.

Fig. 21.1: Venous perforator of great saphenous vein on right side 179

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LAQ-11 Describe great saphenous vein under following heads 1. Formation, 2. Course and relations, 3. Peculiarities, 4. Perforating veins, 5. Termination, 6. Relations, 7. Tributaries, 8. Communicating veins, and 9. Applied anatomy.

Introduction: The great saphenous (Saphes—easily seen) vein is the longest vein of the body. It drains all the structures superficial to fascia lata in whole of the lower extremity except the medial side of leg between tendo calcaneus and tibia. 1. Formation: It is formed by the A. Medial end of dorsal venous arch, and B. Medial marginal vein. 2. Course and relations (Fig. 21.2): It begins at

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Medial end of the dorsal venous arch M for M It is supplemented by medial marginal vein. It runs in front of medial malleolus. It crosses obliquely on medial surface of lower 1/3rd of tibia. It ascends behind the medial border of tibia to reach knee. It runs along medial side of thigh. It pierces the cribriform fascia over the saphenous opening. It drains into femoral vein. 3. Peculiarities: It contains about 10 to 15 valves, which prevent back flow of venous blood. One of the valves is always present at saphenofemoral junction. 4. Perforating veins: They connect great saphenous vein to deep vein. They are three in number (Fig. 21.3A and B). A. Above the ankle, B. Below the knee, and C. Above the knee. It is present in the adductor canal. The perforating veins are provided with valves, which permit the flow of blood only from superficial to deep. 5. Termination: It terminates into upper part of femoral vein by piercing fascia lata. 6. Relations: At ankle joint, the saphenous nerve is anterior to saphenous vein (Fig. 21.4). 7. Tributaries A. At the beginning: Medial marginal vein B. Just below knee

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Fig. 21.2: Course and tributaries of right great saphenous vein

Fig. 21.3A: Direct perforating vein

Fig. 21.3B: Indirect perforating vein

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Fig. 21.4: Relations of right great saphenous vein with nerve and artery

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a. Anterior vein of leg, and b. Posterior arch vein of calf. C. In the thigh a. Posteromedial vein, and b. Anterior cutaneous vein of thigh. D. Before piercing cribriform fascia a. Superficial epigastric vein, b. Superficial circumflex iliac vein, and c. Superficial external pudendal vein. E. Before entering into femoral sheath: Deep external pudendal vein. Box 21.1 Deep circumflex iliac vein is tributary of external iliac vein and not the saphenous vein.

8. Communication vein: Small saphenous vein. 9. Applied anatomy

 Varicosity (torturous, dilated, enlarged and visible vein) of the veins is more common in people who are standing for long time (e.g. traffic police). The valves become incompetent and the flow of the blood is reversed. The defective veins become ‘high pressure leaks’. They produce varicose veins. The area of skin over the dependent part of vein becomes devitalized and results in varicose ulcers. It is one of non-healing ulcers.

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 Great saphenous vein is used for arterial grafting. This is especially used in coronary artery bypass surgery.  During venesection at the ankle joint, one should keep in mind the relation of saphenous nerve. Lesion of saphenous nerve results in loss of sensation on medial side of foot. LAQ-12 Describe venous drainage of lower limb

1. There are three types of veins. A. Superficial, B. Deep, and C. Perforating. a. Features of superficial veins I. They lie superficial to deep fascia, II. They are thick-walled because of the presence of i. Smooth muscle, ii. Fibrous, and iii. Elastic tissues in their walls.

b. Features of deep veins I. They have more valves than the valves in superficial veins. II. They are more efficient channels than the superficial veins. 2. The superficial veins are A. Great or long saphenous vein. Please refer to LAQ-11 B. Small saphenous vein. a. Formation: The vein is formed on the dorsum of the foot by the union of the I. Lateral end of the dorsal venous arch with the II. Lateral marginal vein. b. Course I. It passes behind the lateral malleolus. II. It ascends on the back of leg. III. It lies lateral to the tendo calcaneus. IV. It continues to ascend along the middle line of the calf. V. It ends at the lower part of the popliteal fossa. VI. It pierces the deep fascia and opens into the popliteal vein.

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III. They have valves in the lumen. The numbers of valves increase as they go to distal part. A large proportion of their blood is drained into the deep veins through the perforating veins.

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c. Drainage area: It drains the I. Lateral border of the foot, II. Heel, and III. Back of the leg. d. Connected to the I. Great saphenous, and II. Deep veins. e. Accompanying structure: Sural nerve. 3. Deep veins: They drain the entire structures deep to deep fascia (fascia lata). The deep veins are A. Medial plantar vein B. Lateral plantar a. Dorsalis pedis, b. Anterior tibial, c. Posterior tibial, d. Peroneal, e. Popliteal, and f. Femoral veins and their tributaries.

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4. Perforating veins: They connect the superficial with the deep veins. Their valves permit flow of blood in only one direction. The flow is from the superficial to the deep veins. They are three in number. A. Above the ankle, B. Below the knee, and C. Above the knee. It is present in the adductor canal.

22 Joints of Lower Limb

OLA-47 Which muscles are chief flexors of hip joint?

1. Iliacus, 2. Psoas major, and 3. Pectineus. OLA-48 What is the nerve supply of hip joint?

Nerve supply : The three nerves of the pelvic girdle and lower limb supply the hip joint (Hilton’s law). 1. Femoral nerve (dorsal division of ventral rami of L2, L3, L4) via the nerve to rectus femoris, 2. Sciatic nerve (dorsal and ventral divisions of ventral rami L4, L5, S1, S2, S3) via the nerve to quadratus femoris, and 3. Obturator nerve (ventral division of ventral rami of L2, L3, L4) directly from its anterior division. OLA-49 Name the articulating surface participating in formation of hip joint

There are two bones taking part in hip joint. They are 1. Head of femur, and 2. Articulating surface of acetabular cavity of hip bone. OLA-50 Dislocation of hip joint Table 22.1: The dislocation of hip joint depends upon the position of hip joint at the time of dislocation Position of the hip joint at the time of dislocation • • Flexion of hip joint

Result • Dislocation is posteriorly

• Adduction

• Dislocation without fracture

• Abduction

• Dislocation with fracture 185

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OLA-51 Attachments of capsule of hip joint

1. Attachments of the capsule: The fibrous capsule is attached on the A. Hip bone to the a. Acetabular labrum including the transverse acetabular ligament, and to b. Bone above and behind the acetabulum; B. Femur to the a. Intertrochanteric line in front, and b. One cm medial to the intertrochanteric crest behind. C. Variation of thickness of capsule a. The capsule is thick and firmly attached anterosuperiorly. This part is subjected to maximum tension in the standing posture. b. It is thin and loosely attached posteroinferiorly LAQ-13 Describe hip joint under following heads 1. Classification, 2. Ligaments, 3. Relations, 4. Blood supply, 5. Nerve supply,

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6. Movements, 7. Muscles bringing movements, and 8. Applied anatomy.

1. Classification of hip joint: ABS Axis: Multiaxial. There are three axes. No. of Bones taking part: There are two bones taking part in formation of hip joint. Hence it is classified as simple joint. The bones are a. Head of femur, and b. Articulating surface of acetabular cavity of hip bone. Surfaces of articulating bones are spherical and socket like. Hence, it is classified as ball and socket type of synovial joint. 2. Ligaments A. Capsule a. Attachments I. Superiorly: It is attached superiorly 5 to 6 mm above the acetabular margin of hip bone. II. Inferiorly i. Anteriorly: On the intertrochanteric line. ii. Posteriorly: One cm medial to intertrochanteric crest.

187

b. Variation in thickness I. Anterosuperiorly: It is thick and attached firmly. It is subjected to maximum tension in standing. II. Posteroinferiorly: It is thin and loosely attached to bone. c. Types of fibres: There are two types of fibres I. The outer fibres are longitudinal and are best developed anterosuperiorly. They are called retinacula. The blood vessel supplying head and neck of femur travel along these retinacula. II. The inner fibres are circular and are called zona orbicularis. d. Capsule is re-enforced by I. Iliofemoral, II. Pubofemoral, III. Ischiofemoral ligaments, IV. Acetabular labrum, V. Transverse acetabular ligament, and VI. Ligament of the head of the femur (ligamentum teres) e. Synovial membrane: It lines I. The inner surface of fibrous capsule, II. Intracapsular portion of neck of femur, III. Both surfaces of acetabular labrum, IV. Transverse acetabular ligament, and V. Fat in the acetabular fossa. f. Acetabular labrum (labrum—edge, brim). It is fibrocartilage. Functions: DAMP Deepens the acetabular cavity. Accommodates distal end of the head of femur. Thus, it protects the socket in case of pulling the head of the femur. Maintains the bony contacts Protects the edges. B. Iliofemoral ligament (ligament of Bigelow) a. It is Y-shaped, strongest ligament in the body. b. It extends from the anterior inferior iliac spine to the intertrochanteric line. c. It prevents backwards falling. C. Pubofemoral ligament lar. a. It is b. It extends from iliopubic eminence, obturator crest and obturator membrane to inferior part of capsule. D. Ischiofemoral ligament a. It should be ideally called ischiocapsular because it is attached to inner layer of capsule.

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Exam-Oriented Anatomy

b. It is weak and almost horizontal across the capsule of hip joint. I. It extends from i. Posterior inferior surface of acetabular margin to ii. Posterior part of neck of femur. II. It is continuous with zona orbicularis. E. Ligament of head of femur (ligamentum teres or round ligament) a. It is flat and lar. b. Its apex is attached to the depression present on the head of femur called fovea centralis, and c. Base is attached to I. Transverse acetabular ligament, and II. Margins of acetabular notch by two bands. d. It transmits arteries of head of femur (from acetabular branches of the obturator and medial circumflex femoral arteries). F. Transverse ligament of the acetabulum a. It is a part of acetabulum, and b. It bridges the notch.

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3. Relations (Fig. 22.1) A. Posterior a. Tendon of I. Obturator externus, and II. Obturator internus. b. Gemelli, and c. Piriformis. B. Superior a. Reflected head of rectus femoris, and b. Gluteus minimus. C. Inferior a. Pectineus and cover of gluteus maximus, and b. Obturator muscle. 4. Nerve supply : There are three nerves of the pelvic girdle and lower limb that supply the hip joint (Hilton’s law). A. Femoral nerve (dorsal division of ventral rami of L2, L3, L4) via the nerve to rectus femoris, B. Sciatic nerve (dorsal and ventral divisions of ventral rami of L4, L5, S1, S2, S3) via the nerve to quadratus femoris, and C. Obturator nerve (ventral division of ventral rami of L2, L3, L4) directly from its anterior division.

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Fig. 22.1: Relations of right hip joint

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5. Blood supply A. Obturator artery branch of anterior division of internal iliac artery. B. Ascending branches of medial circumflex femoral artery branch of profunda femoris artery. C. Ascending branches of lateral circumflex femoral branch of profunda femoris artery. These supply the neck and head of the femur. 6. Movements A. Axis a. Transverse axis of hip joint I. Flexion: i. Psoas major, and ii. Iliacus are powerful flexors. II. Extension: Muscles i. Gluteus maximus, and ii. Hamstring muscles. • Ischial fibres of adductor magnus, • Biceps femoris, • Semimembranosus, and • Semitendinosus. b. Sagittal axis of hip joint I. Adduction i. Adductor magnus,

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ii. Adductor longus, and iii. Adductor brevis. II. Abduction i. Gluteus medius, and ii. Gluteus minimus. c. Longitudinal axis of hip joint I. Medial rotation i. Tensor fascia lata, and ii. Anterior fibres of gluteus medius. II. Lateral rotation i. Gluteus maximus, ii. Obturator internus and externus, iii. Superior and inferior gemelli, iv. Piriformis, and v. Quadratus femoris. 7. Applied anatomy

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 Congenital dislocation is more common in hip joint than in any other joint.  The position of the hip joint is weak in flexion and lateral rotation of femur. Hence posterior dislocation (dashboard injury) is more common.  Anterior dislocation is less common.  Central dislocation is very rare.  Fracture of neck of femur occurs between 40 and 60 years.  Disease of hip joint may produce shortening of limb. Disease of hip may cause referred pain to knee joint. SN-24

Classify knee joint (genual)

1. Structurally: ABCS Axis: Uniaxial Modified hinge joint: The movements are in transverse axis. The movements permitted are flexion, extension hence hinge joint. The transverse axis is not fixed, so it is modified hinge joint. Number of Bones: There are three bones in the knee joint sharing a common capsule. Hence, it is a compound joint. Complex: Joint is divided into two compartments by a fibrocartilage structure— menisci. Condylar: Medial and lateral condyles of femur and tibia are taking part. Shape: Saddle-shaped: concave

convex

Between femur and patella, the surface of which is and reciprocating convex concave.

2. Functionally: Diarthrosis (freely movable).

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191

Capsule of knee joint

1. Attachments (Fig. 22.2) A. To femur: It is attached to the peripheral margin of articular surface of lower end of femur. a. It excludes articulating area of patella. b. It includes tendon of popliteus. B. To tibia: It is attached 1 cm distal to articular margin. a. Anteriorly, it is attached along the upper margin of the tibial condyles. b. Posteriorly, it is attached to the intercondylar ridge. C. Deficient at a. Tibial tuberosity on tibia, and b. Gap for popliteal tendon behind the lateral condyle of tibia for the passage of tendon of popliteus. D. Strengthened by a. Anteriorly by medial and lateral patellar retinacula, b. Posteriorly by oblique popliteal ligament, c. Laterally by iliotibial tract, and d. Medially by tendon of sartorius and semimembranosus.

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Fig. 22.2: Capsule of right knee joint

Box 22.1 The ligamentum patellae, coronary and medial ligaments are the parts of fibrous capsule. Lateral ligament is not the part of fibrous capsule. SN-26

Draw and label the diagram showing anastomosis around knee joint

Five genicular branches of the popliteal artery (Fig. 22.3) A. Descending a. Genicular branch of the femoral artery, and b. Branch of the lateral circumflex femoral artery.

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B. Two recurrent branches of the anterior tibial artery, and C. Circumflex fibular branch of the posterior tibial artery.

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Fig. 22.3: Anastomoses around the right knee joint from front

SAQ-20 Enumerate intra-articular structures of knee joint

The most important structure is cruciate ligament. The other intra-articular structures include the menisci, and the femoral tendon of popliteus (Fig. 22.4). The other structures are: The intra-articular structures start with the first letters of days of the week

M T W T F S C.

Menisci (Mon), Tendon of popliteus (Tue), Meniscofemoral ligament (Wed—the first letter of Wednesday is inverted M), Transverse ligament (Thu), Haversian pad of fat (Fri), Synovial membrane (Sat), and Coronary ligament (Cun) (The pronunciation of c and s is similar)

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Fig. 22.4: Relations of intra-articular structures of right knee joint

Cruciate ligament

Introduction: The ligaments connecting the femur and tibia are in the form of cross. Hence, they are called cruciate ligaments. The nomenclature is based on the attachments to the part of upper surface of tibia. 1. Functions A. It is key stabilizer of knee joint. B. It checks anterior and posterior movements of the femur on tibia. 2. Attachments (Fig. 22.5) LAMP Lateral condyle gives attachment to Anterior cruciate ligament. Medial condyle gives attachment to Posterior cruciate ligament. Anterior cruciate ligament extends from anterior part of upper surface of tibia to the lateral condyle of femur. Posterior cruciate ligament extends from posterior part of upper surface of tibia to the medial condyle of femur. 3. Morphology: The posterior cruciate ligament is stronger, shorter and less oblique. In weight-bearing, flexed knee, posterior cruciate ligament is the only stabilizing factor. 4. Functions A. Anterior cruciate ligament prevents the anterior displacement of tibial condyle on femur. It prevents sliding of the femur backwards on tibia. B. Posterior cruciate ligament prevents the posterior displacement of tibial condyle on femur. It prevents femur from sliding forward. Both cruciate ligaments prevent side-to-side displacement of tibia and femur.

3 Lower Limb

SN-27

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Fig. 22.5: Attachments of cruciate ligaments of right knee

SN-28

Compare anterior and posterior cruciate ligaments Table 22.2: Comparison of anterior and posterior cruciate ligaments (Fig. 22.6)

Particulars

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• Attachments

Anterior cruciate ligament

Posterior cruciate ligament

• To tibia

• Anterior part of intercondylar area of tibia

• Posterior part of intercondylar area of tibia

• To femur

• Posterior part of medial surface of lateral condyle of femur

• Anterior part of lateral surface of medial condyle of femur

• Direction of fibres

• Upwards, backwards and • Upwards, forwards and laterally medially

• Strength of fibres

• Weaker and longer

• Stronger, shorter and less oblique.

• Position

• Taut during extension of knee joint

• Taut during flexion of knee joint

• Blood supply

• Middle genicular vessels

• Nerve supply

• Middle genicular nerves branch of tibial nerve.

• Function is just opposite to its name

• Prevents backward displacement of femur

• Force on upper end of tibia

• Force which pushes upper • Force which pushes upper end end of tibia forwards of tibia backwards ruptures ruptures anterior cruciate anterior cruciate ligament ligament

• Prevents forward displacement of femur

Contd.

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Table 22.2: Comparison of anterior and posterior cruciate ligaments (Contd.) Particulars

Anterior cruciate ligament

• Integrity

Posterior cruciate ligament • Integrity of PCL is more important when walking downstairs. Main stabilizing factor for the femur.

• Damage

• Commonly damaged

• Less commonly damaged.

• Injury

• Injured in anterior dislocation of tibia

• Injured in posterior dislocation of tibia.

Fig. 22.6: Drawer sign test for anterior and posterior cruciate ligaments

Meniscus

(Menisco—crescent, half moon) Introduction: It is a semilunar, fibrocartilaginous ring, the articular surfaces of the condyles of tibia.

lar in cross-section, covers

1. Functions: The chief role of meniscus is to A. Rotate the femur, and to B. Spread the synovial fluid uniformly. Box 22.2 Note: They are never subjected to weight bearing. The functions of meniscus can be summarized by using “MENISCUS” word as mnemonics.

Maintains the bony contact and potential joint space. Escorts the articular surfaces. Nourishes the articular surface. Increases the concavity of tibial condyle. Serves as a cushion. Deepens the joint cavity. Spreads the synovial fluid uniformly. Saves from the shock during weight transmission.

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SN-29

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Exam-Oriented Anatomy

2. Number: There are two menisci—medial and lateral. 3. Attachment (Fig. 22.7) A. Each meniscus has anterior and posterior horns. Both the horns of both the menisci are attached to the anterior and posterior intercondylar areas, respectively. B. The medial margin of the medial meniscus and lateral margin of lateral meniscus are attached to the capsule of the knee joint. C. The medial margin of the medial meniscus is also attached to the tibial collateral ligament. D. The posterior horn of lateral meniscus provided attachment to a. The meniscofemoral ligament, and b. Fibres of the popliteus.

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3 Fig. 22.7: Attachments of the menisci

4. Movements A. The flexion and extension movements occur in the upper compartment. B. The rotation movement occurs in the lower compartment. 5. Applied anatomy : The medial meniscus is more prone for injury as it is more firmly attached to the capsule and tibial collateral ligament. SAQ-21 Meniscofemoral ligaments

Introduction: They connect the lateral meniscus to medial condyle of femur. 1. Attachments A. They arise from posterior horn of lateral meniscus and get attached to medial condyle of the femur.

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B. They are named anterior and posterior meniscofemoral ligaments. The anterior meniscofemoral ligament passes anterior to the posterior cruciate ligament and posterior meniscofemoral ligament passes posterior to the posterior cruciate ligament. 2. Function: They regulate the forward movement of the lateral meniscus during extension of the knee. SAQ-22 Oblique popliteal ligament

The oblique popliteal ligament is an expansion of tendon of semimembranosus muscle (Fig. 22.8). It extends from posterior surface of medial condyles of tibia to lateral part of intercondylar line of femur. This forms the floor of popliteal fossa. It is pierced by 1. Middle genicular vessels and nerves, and 2. Genicular branch of posterior division of obturator nerve.

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Fig. 22.8: Right oblique popliteal ligament

OLA-52 Transverse ligament (transverse meniscal ligament)

It connects anterior horn of medial meniscus to anterior margin of lateral meniscus. It is present in 40% of individuals. SAQ-23 Synovial membrane of knee joint

Introduction: It lines the inner surface of capsule and extends on patella. It is a mere capillary film. 1. Amount of synovial fluid—0.5 ml. 2. Features

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A. Infrapatellar synovial fold: It is a flattened hollow cone

of synovial membrane.

It has a base and an apex. a. Base is opened. It extends from articular cartilage of patella to the anterior intercondylar area of tibia. b. Apex: It is attached to the most anterior point of the intercondylar notch of femur. B. Synovial cavity: There are three cavities—a patellar and two condylar. C. Bursae: There are three bursae a. Suprapatellar bursa: It is deep to quadriceps femoris tendon. b. Popliteal bursa: It opens into lateral condylar cavity. It is below the meniscus. c. Gastrocnemius bursa: It is deep to medial head of gastrocnemius. OLA-53 Coronary ligament

Introduction: It is a part of fibrous capsule. It connects 1. Convex margins of medial and lateral menisci to 2. Upper end of tibia. OLA-54 Arcuate ligament

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Introduction: It is Y-shaped fibrous band. 1. The stem of the arcuate ligament is fixed to styloid process of fibula. 2. The anterior band is attached to lateral condyle of femur. 3. The posterior band is attached to lateral condyle of tibia. OLA-55 Ligamentum patellae

Introduction: Ligamentum patellae derived from tendon of quadriceps femoris and extend from the apex of patella to the tibial tuberosity (Fig. 22.9).

Fig. 22.9: Ligamentum patellae

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Collateral ligaments

The collateral ligaments are present on the medial and lateral side of knee joint. These can be described as follows (Table 22.3 and Fig. 22.10). Table 22.3: Details of collateral ligament Particulars

Medial collateral ligament

Lateral collateral ligament

• Proximal attachment

• Arises from medial femoral epicondyle

• Arises from lateral femoral epicondyle

• Distal attachment

• Inserted into shaft of tibia

• Inserted into styloid process of the head of fibula

• Shape

• Broad and fan shaped

• Strong, narrow and cord like

• Palpable

• No

• Yes

• Functions

• Prevents excessive abduction

• Prevents excessive adduction

• Phylogenetically

• Represents ischial fibres of adductor magnus

• Represents peroneus longus

• Attachment to capsule

• Fused to joint capsule

• Relatively free

• Attachment to meniscus • Attached to meniscus

• Not attached to meniscus

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Fig. 22.10: Collateral ligaments and their attachments of right knee joint

SN-31

Relations of knee joint (Fig. 22.11)

1. Anterior: Quadriceps femoris. 2. Posterior A. Popliteal vessels, B. Tibial nerve, and C. Lateral and medial head of gastrocnemius.

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Fig. 22.11: Transverse section to the knee joint showing the relations of structures of knee joint

3. Medially

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3

A. B. C. D. E.

Medial patellar retinaculum, Sartorius, Gracilis, Semimembranosus, and Semitendinosus.

4. Laterally A. Common peroneal nerve, B. Lateral patellar retinaculum, and C. Tendon of biceps femoris. SN-32

Movements of knee joint and muscles bringing the movements of knee joint

1. Flexion A. Main muscles a. Hamstring muscles, I. Semimembranosus, II. Semitendinosus, and III. Biceps femoris.

201

b. Sartorius, and c. Gracilis. B. Accessory muscles a. Gastrocnemius, and b. Plantaris. 2. Extension A. Main muscles a. Quadriceps femoris, and b. Tensor fascia lata. B. Accessory muscle C. Muscular slips of articularis genu 3. Rotation of the knee joint: May be adjuvant or conjunct. A. Adjuvant (aiding, assisting, independent of flexion and extension) rotation. Rotation around the vertical axis independent of flexion and extension, e.g. when foot is off the ground and knee in semiflexed position, tibia rotates medially and laterally around the vertical axis. B. Conjunct (associated and integrated with flexion and extension) rotation a. It takes place along with flexion and extension of knee joint. b. In last 30° of extension, the anterior cruciate ligament is stretched. c. It acts as a vertical axis around which the medial condyle of femur rotates in backwards and medially. d. It (medial condyle of femur) reaches the anterior horn of medial meniscus and completely obliterates the medial meniscofemoral compartment. e. This completes the last 30° of extension. f. It is achieved by conjunct rotation of medial condyle of femur on tibia. g. This mechanism locks the knee joint. h. During unlocking, the popliteus contracts. It causes the lateral rotation of medial condyle of femur on tibia. MRF for locking 4. Locking: The key word is A. Definition: It is Medial Rotation of the Femur on fixed tibia, or Lateral rotation of tibia on fixed femur. B. Muscle: Quadriceps femoris C. Medial rotation: Semimembranosus, semitendinosus, gracilis and sartorius. D. Lateral rotation: Biceps femoris. 5. Unlocking A. Definition: It is a. Lateral rotation of femur on fixed tibia, or b. Medial rotation of tibia on fixed femur. B. Muscle: Popliteus.

3 Lower Limb

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SAQ-24 Stability of knee joint

The stability of knee joint is maintained by following structure 1. The cruciate ligaments are indispensable for anteroposterior stability in flexion. 2. Vastus medialis is indispensable to the stability of patella. 3. Spines of tibia prevent side way gliding. 4. Ilio-tibial tract, gluteus maximus and tensor fascia lata stabilizes slightly flexed knee joint. 5. Bones do not play any role. SN-33

Bursae around knee joint (Fig. 22.12)

1. Anterior bursae: They are anterior to knee joint. They are A. Subcutaneous: It is present beneath the skin. They may be a. Subcutaneous pre-Patellar, e.g. Housemaid’s knee—PPH Box 22.3 Note:

PPH is key word to remember bursa and its example.

The 1st letter of ‘PPH’ indicates Pre The 2nd letter of ‘PPH’ denotes Patella The 3rd letter of ‘PPH’ helps to recollect the example: Housemaid’s knee.

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b. Subcutaneous infrapatellar, e.g. Clergyman’s Knee—SICK. Box 22.4 Note:

“SICK” is key word to remember bursa and its example.

The 1st letter “S” indicates Subcutaneous The 2nd letter “I” denotes Infrapatellar The 3rd letter “C” helps to recollect the example—Clergyman’s. The 4th letter “K” helps to recollect the example—Knee

B. Deep a. Suprapatellar, and b. Infrapatellar. 2. Lateral bursae between A. Lateral condyle of tibia and tendon of popliteus, B. Popliteus and fibular collateral ligament, C. Fibular collateral ligament and biceps femoris, and D. Deep to lateral head of gastrocnemius.

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Fig. 22.12: Bursae around the knee joint

SN-34

Locking and unlocking of knee joint

Introduction: The function of locking and unlocking of knee joint is to keep the knee in full extension without muscular effort. It is brought by A. Medial rotation of femur on fixed tibia during terminal stage of extension. B. Lateral rotation of femur on fixed tibia during early stage of flexion. 1. Necessity of the movements of locking and unlocking A. The surface area of articular surfaces of tibia and femur are not proportionate. B. The articular surfaces of tibia and femur are incongruent. C. During the terminal part of extension of knee joint, the small articular surface of the tibia is used up by the femur. To accommodate the unused articular surface of femur on tibia, the femur or tibia is required to rotate. This is done to have the stable movement.

3 Lower Limb

3. Medial A. Deep to medial head of gastrocnemius, B. Anserine bursa a. It is a complicated bursa, b. It separates the members of guy ropes from one another. The members of the guy ropes are sartorius, semitendinosus, and gracilis, and c. It also separates from tibia and tibial collateral ligament. C. Deep to tibial collateral ligament, D. Deep to semimembranosus, and E. Between semimembranosus and semitendinosus.

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2. Difference between locking and unlocking (Table 22.4) Table 22.4: Difference between locking and unlocking of knee joint. Particulars

Locking

Unlocking

• Position of bone

•

• When tibia is fixed • When femur is fixed

• Medial rotation of femur • Lateral rotation of tibia

“MRF”

• Muscles bringing

• Quadriceps femoris

• Popliteus

• Ligaments bringing

• Oblique popliteal • Medial collateral • Lateral collateral

............

. Position of the joint

• In terminal part of extension of knee joint

• In initial flexion from extreme extension of knee joint

• Lateral rotation of femur • Medial rotation of tibia

LAQ-14 Describe ankle joint (talocrural) under following heads 1. Bones taking part, 2. Classification, 3. Ligaments, 4. Movements and muscles producing movements, 5. Relations,

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3

6. Arterial supply, 7. Nerve supply, and 8. Applied anatomy.

1. Bones taking part A. Lower end of fibula with lateral malleolus, B. Medial malleolus of tibia, and distal part of tibia, and C. Superior surface of talus. 2. Classification A. Structural:

ABCS

Axis: Uniaxial, modified hinge (since the axis of movement is basically transverse with a slight downward inclination on the lateral side) variety of synovial joint. Number of bones: Articulating bones in the formation of ankle joint are three and they are tibia, fibula and talus. Hence it is compound synovial joint. B. Functional: Diarthrosis (freely mobile). 3. Ligaments (Fig. 22.13) A. Fibrous capsule covers the joint completely a. Attachments I. It is attached superiorly to the peripheral margins of the articular surfaces of lower end of tibia and fibula.

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II. It is attached inferiorly to the peripheral margin of i. Articular surface of the superior surface of talus. ii. Comma-shaped facet present on the medial surface of talus. iii.

lar facet present on the lateral surface of talus.

b. Variations in thickness I. Thin in front, thin behind. II. Thick laterally, thick medially. c. Fate: It blends with collateral ligament. B. Synovial membrane a. It lines the inner surface of the fibrous capsule. b. It stops at the periphery of the articular cartilage. c. A small synovial recess extends upwards in the inferior tibiofibular joint. C. Deltoid ligament: It is a strong lar ligament present on the medial side of the ankle joint. It has superficial and deep parts. D. Lateral ligament: It is a ligament present on the lateral side of ankle joint. It connects talus and calcaneum with fibula.

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Fig. 22.13: Ligaments of the ankle joint

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Exam-Oriented Anatomy

4. Movements and muscles producing movements A. Dorsiflexion a. Range of movement—10°–20° b. All muscles of anterior or extensor compartment of the leg bring dorsiflexion of the ankle joint, i.e. I. Tibialis anterior, II. Extensor hallucis longus, and III. Extensor digitorum longus. B. Plantar flexion a. Range of movement is 20°–40°. b. All the muscles of flexor compartment of the leg are plantar flexors of ankle joint. c. The gastrocnemius with soleus acts as prime mover. d. The peroneus longus and brevis come into play in extreme plantar flexion. The muscles bringing plantar flexion are I. Peroneus tertius, II. Tibialis posterior, III. Flexor digitorum longus, IV. Flexor hallucis longus, V. Tendo Achilles. C. In symmetrical standing, the line of gravity passes slightly in front of the ankle joint, therefore, there is a natural tendency for forward dislocation which is prevented by a. Broader anterior part of trochlear surface of talus, and b. Tonic contraction of triceps surae. 5. Relations A. Anterior (From medial to lateral) Timid Husbands Are Never Dear Persons Tibialis anterior Extensor Hallucis longus Anterior tibial Artery Anterior tibial Nerve Extensor Digitorum longus Peroneus tertius B. Posterior: Behind tibial malleolus. Talented Doctors are never hungry. (From anterior to posterior) Tendon of tibialis posterior, Flexor digitorum longus, Posterior tibial artery, Tibial nerve, and Tendon of flexor hallucis longus.

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C. Behind the fibular malleolus: Tendon of peroneus brevis and peroneus longus. The peroneus brevis is situated deep and peroneus longus is situated superficially. 6. Arterial supply : Malleolar branches of anterior tibial and peroneal arteries. 7. Nerve supply : Branches from deep peroneal and tibial nerves. 8. Applied anatomy

 Ankle sprain: It is due to over inversion of foot, which is one of the common manifestations. The anterior talofibular and calcaneofibular ligaments are sometimes torn and in severe cases the anterior part of the capsule of the ankle joint is ruptured.  Pott’s fracture: The forceful eversion of the foot causes avulsion of the deltoid ligament, fracture of the tibia and fibula. This is described in 3 degrees. A Fracture Of ankle joint

SN-35

Deltoid ligament

Introduction: It is a strong lar ligament present on the medial side of the ankle joint and it has superficial and deep parts. 1. Superficial part lar. A. It is is attached to tarsal bones, namely navicular, calcaneum B. The base of the and talus. C. The apex is attached to the tip of medial malleolus. They are subdivided into anterior, middle and posterior fibres. a. Anterior fibres extend from medial malleolus of tibia to I. Tuberosity of navicular bone, and to the II. Medial margin of spring ligament. These fibres are present anteriorly; hence they are called anterior fibres of deltoid ligament or tibionavicular ligament.

3 Lower Limb

 In 1st degree there is only an Avulsion (tearing) of deltoid ligament.  In 2nd degree Avulsion (tearing) of deltoid ligament Fracture of medial malleolus of tibia.  In 3rd degree Avulsion fracture of the deltoid ligament, Fracture of medial malleolus of tibia, and Oblique fracture of the lower part of the fibula.  The ankle sprains usually occur when the foot is plantar flexed.  The sprains of the ankle joint are almost always abduction sprains of the subtalar joints.

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b. Middle fibres extend from medial malleolus of tibia to sustantaculum tali of calcaneum. They are called tibiocalcanean ligament. c. Posterior fibres extend from medial malleolus of tibia to the medial tubercle of talus. They are also called superficial tibiotalar ligament.

Fig. 22.14: Deltoid ligament

2. Deep part blends with fibrous capsule. It connects tibial malleolus to anterior part of medial surface of talus below comma shaped facet. This is also called deep tibiotalar ligament. OLA-56 Movements of ankle joint Table 22.5: Movements of ankle joint

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Movements

Principal muscle

Accessory muscle

• Dorsiflexion

• Tibialis anterior

• Extensor hallucis longus • Extensor digitorum longus • Peroneus tertius

• Plantar flexion

• Gastrocnemius • Soleus

• • • •

Tibialis posterior Flexor digitorum longus Flexor hallucis longus Plantaris

SAQ-25 Lateral ligaments of ankle joint Table 22.6: Details of lateral ligaments of knee joint Particulars

Direction

Attachment

• Anterior talofibular ligament (weak)

• Forward and medially

• It extends from the anterior margin of the fibular malleolus to the lateral surface of neck of talus.

• Posterior talofibular ligament

• Backward and medially

• It extends from the posterior margin of fibular malleolus to the posterior tubercle of talus.

• Calcaneofibular ligament

• Downwards and backwards

• It extends from notch on the lower border of the lateral malleolus to the tubercle on the lateral surface of calcaneum.

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LAQ-15 Describe inversion under following heads 1. Bones taking part, 2. Joints and classification of joints, 3. Axis, 4. Combination of action, 5. Range of movements, 6. Functions, and 7. Applied anatomy.

Fig. 22.15: Axis of inversion at talocalcaneonvavicular

3 Lower Limb

Introduction: It is a movement in which the medial border of foot is elevated so that the sole or plantar surface of the foot faces medially. Inversion and eversion are best demonstrated when the foot is off the ground. When the foot is on the ground typical inversion and eversion are not observed. The malleoli lock the talus and suspended foot inverts and everts around it. 1. Bones taking part: Talus, calcaneus and navicular. 2. Joints and classification of joints A. Talocalcaneonavicular: Ball and socket variety of synovial joint. B. Subtalar: Plane synovial joint. 3. Axis: It is an oblique axis. Its direction is forwards, upwards and medially. It passes from the back of lateral tubercle of calcaneus, through sinus tarsi. It emerges at the superomedial aspect of neck of talus. This axis corresponds to abduction, adduction, plantar flexion and dorsiflexion and medial and lateral rotations of calcaneus (Fig. 22.15). 4. Combination of movements: Adduction, plantar flexion, rotation and gliding movements.

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5. Range of movements: It is freer as compared to the eversion. 6. Functions A. The inversion movement helps to walk on slippery and uneven surfaces. B. It helps to maintain an efficient shift of weight distribution among the head of metatarsal bones during locomotion. 7. Applied anatomy Table 22.7: Condition of foot and details S no. Condition

Meaning

Position of heel

Position of toes

1.

Talipes calcaneovarus • Talipes club foot, varus bent inward

• Turned inwards

• Elevated

2.

Talipes calcaneovalgus

• Valgus bent outward

• Turned outward

• Elevated

3.

Talipes equinovalgus

• Equin—horse

• Elevated and turned outward

4.

Talipes equinovarus

• Turned inwards

 Inversion sprain is the most common ankle injury. It involves the tearing of lateral collateral ligaments. Usually, the anterior talofibular ligament is torn first, then the calcaneofibular ligament and in severe cases, the posterior talofibular ligament.

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LAQ-16 Describe eversion under following heads 1. Bones taking part, 2. Axis, 3. Combination of action, 4. Range of movements, 5. Muscles bringing movement, 6. Functions, and 7. Applied anatomy.

Introduction: It is a movement in which the lateral border of the foot is elevated so that sole or plantar surface of the foot faces laterally when the foot is off the ground. Eversion is a combination of pronation and abduction. 1. Bones taking part: Calcaneum, talus and cuboid. 2. Axis: An oblique axis runs forwards, upwards and medially. It passes from the back of lateral tubercle of calcaneus. It passes through sinus tarsi to emerge at the superomedial aspect of neck of talus. This axis corresponds to abduction, adduction, plantar flexion and dorsiflexion and medial and lateral rotations of calcaneus (refer to Fig. 22.15). 3. Combination of action: Abduction, dorsiflexion, rotation and gliding. 4. Range of movements: It is less free as compared to inversion. 5. Muscles bringing movements A. Peroneus longus, B. Peroneus brevis, and C. Peroneus tertius.

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Peroneus longus and brevis whose tendons pass behind lateral malleolus are plantar flexors. The peroneus tertius is dorsiflexors of ankle joint. These opposite effects cancel each other and produce simple eversion movement. Eversion is a movement of pronation and is accompanied by abduction of the fore part of the foot. 6. Functions A. To walk on slippery and uneven surfaces. B. To maintain an efficient shift of weight distribution among the head of metatarsal bones during locomotion. 7. Applied anatomy

 Talipes calcaneovarus: A deformity of the foot in which the heel is turned toward the midline of the body and the anterior part is elevated.  Talipes calcaneovalgus: A deformity of the foot in which the heel is turned outward from the midline of the body and the anterior part of the foot is elevated.  Talipes equinovalgus: A deformity of the foot in which the heel is elevated and turned outward from the midline of the body.  Talipes equinovarus: A deformity of the foot in which the heel is turned inward from the midline of the leg and the foot is plantar flexed. This is typical club foot.  Eversion sprains, which are less common, usually involve tearing of the deltoid ligament. Compare pronation, supination with inversion and eversion Table 22.8: Comparison of pronation, supination with inversion and eversion Character

Pronation/supination (Fig. 22.16)

Inversion/eversion

• Joints

• Superior and inferior radioulnar joints

• Subtalar • Talocalcaneonavicular • Transverse tarsal

• Plane of axis

• Vertical axis passes downward and medially

• An oblique axis which runs forward and medially

• Direction of axis

• Through the centre of head of the radius and the ulnar attachment of the articular disc

• It passes from the back of the calcaneum, through the sinus tarsi to emerge at the superomedial aspect of the neck of the talus.

• Distance between joints

• Far apart

• Close together

SN-37

Spring ligament (plantar calcaneonavicular ligament)

Introduction: It is an anterior segmental tie (staples) and is one of the important ligaments in the maintenance of medial longitudinal arch (Fig. 22.17). 1. Extent: It extends from sustantaculum tali of calcaneus to tuberosity of navicular bone.

3 Lower Limb

SN-36

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Fig. 22.16: Kings pronate and beggars supinate

Lower Limb

3 Fig. 22.17: Spring ligament in right ankle joint

2. Functions A. It supports the head of talus, and B. It provides attachment to deltoid ligament. 3. Applied anatomy : If this ligament is stretched, the navicular and calcaneum move away from each other and the head of the talus sinks and arch is flattened. It is supported by tibialis posterior, tendons of flexor digitorum brevis, and abductor hallucis.

23 Arches of Foot

SAQ-26 Applied anatomy of arches of foot

1. Absence of arches is called flat foot. It is also called pes planus. 2. The exaggeration of longitudinal arch of the foot is known as pes cavus. 3. The deformities of foot A. Clubfoot (a congenital deformity of the foot. which is twisted out of shapes or position) B. Talipes calcaneus: Person walks on heel (talipes—clubfoot). C. Talipes equinus: Person walks on toes. D. Talipes varus: The foot is bent inwards, persons walk on the outer border, and the foot is inverted and adducted. E. Talipes valgus: Bent outwards, person walks on inner border of foot, i.e. foot everted and abducted. F. Talipes equinovarus: Clubfoot, inverted, adducted and plantar flexed. It is associated with spina bifida. OLA-57 Enumerate functions of the foot

1. Acts as a pliable platform to support the body weight during standing position. This is achieved by elastic arches. The arches are segmented to sustain the stress of weight. They thrust the weight at the optimum level. 2. It acts as a lever to propel the body forward during walking, running, and jumping. OLA-58 Name the inverters of foot

1. Tibialis anterior, 2. Tibialis posterior, 3. Flexor digitorum longus, and 4. Flexor hallucis longus. 213

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OLA-59 Talipes equinovarus—clubfoot

1. It is the most common type of foot deformity. 2. Foot is inverted, adducted and plantar flexed. 3. The condition may be associated with spina bifida. 4. Talipes (clubfoot) may be of two types A. Talipes calcaneovalgus: Foot is dorsiflexed at ankle joint, everted at midtarsal joints. B. Talipes equinovarus: Foot is plantar flexed at ankle joint and inverted at midtarsal joints. 5. High medial longitudinal arch. SAQ-27 Supports of arches

1. The medial arch is supported by A. Spring ligament: It supports the head of the talus. B. Plantar aponeurosis: It acts as a tie beam. C. Abductor hallucis and flexor digitorum brevis: They act as spring ties. D. Tibialis anterior: It lifts the centre of the arch. It also forms a stirrup-like support with the help of peroneus longus muscle.

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3

E. Tibialis posterior: It adducts the midtarsal joint and supports the spring ligament. F. Flexor hallucis longus: It extends between the anterior and posterior ends of the arch and supports the head of talus. 2. Lateral longitudinal arch is supported by the structures forming the tie beam. They are A. Long plantar ligament, B. Short plantar ligament, C. Plantar aponeurosis, D. Flexor digitorum brevis, E. Flexor digiti minimi, and F. Abductor digiti minimi. 3. Peroneus longus, peroneus brevis and peroneus tertius support the arch. LAQ-17 Describe medial longitudinal arch under following heads 1. Functions, 2. Formations of the arch, 3. Factors maintaining arch, and 4. Applied anatomy.

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1. Functions: The main functions of the arch are, A. Helps to a. Absorb shock, b. Propel the body in walking, running and jumping, and c. Walk on the uneven surfaces. B. Increases pliability, C. Brings resilience, 2. Formation of the arch (Fig. 23.1) A. Ends a. Anterior end is formed by heads of 1st, 2nd and 3rd metatarsals. b. Posterior end is formed by medial tubercle of calcaneum (it is short and strong). B. Summit is formed by superior articular facet of body of talus. C. Pillar a. Anterior pillar is formed by three cuneiform bones, navicular and talus. b. Posterior pillar is formed by medial ½ of the calcaneum. D. Joint: Talocalcaneonavicular. E. Classification of joints: Ball and socket type of synovial joint.

Lower Limb

3 Fig. 23.1: Medial longitudinal arch of right foot

3. Factors maintaining arch A. Bones: They are not responsible for maintaining the stability of the arch. The bones are mostly wedge shaped with narrower edge facing plantar surface. The head of talus acts as keystone. B. Tie beam (bow string) a. Plantar aponeurosis: It is a most important ligament stretching like a tie beam. By the contraction, it increases the height of the arch. b. Flexor hallucis longus: It also acts as tie beam. It extends from sustantaculum tali to great toe. It gives slip to its weakest sister flexor digitorum longus, which acts on the medial 3 digits. It is most efficient means of maintaining an arch as it ties the two pillars. This is the bulkiest of the calf muscles, which is multipennate.

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Box 23.1 Note: For short standing, ligaments support the arch. For prolonged standing ligaments ‘tire’, relief is obtained by pressing the pads of the toes to the grounds. During the movements of propulsion and during landing on the feet, the strain is taken by the tendon of flexor hallucis longus.

c. Intersegmental ties (staples) I. Spring ligament: It extends from sustantaculum tali of calcaneus to tuberosity of navicular bone. It is next important ligament for maintenance of medial longitudinal arch. II. Flexor hallucis brevis also acts as staples. d. Slings: They are I. Tendon of tibialis anterior, and II. Tendon of peroneus longus. They are inserted into the same two bones (medial cuneiform and 1st metatarsal bone). Tibialis anterior increases the height of medial longitudinal arch. Peroneus longus decreases height of the medial longitudinal arch. e. Tibialis anterior and posterior have a significant influence on the medial longitudinal arch as they bring out inversion. 4. Applied anatomy

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3

 Absence of arches is called flat foot. It is also called pes planus.  The exaggeration of longitudinal arch of the foot is known as pes cavus.  The deformities of foot (Fig. 23.2).  Clubfoot (a congenital deformity of the foot, which is twisted out of shapes or position)  Talipes calcaneus: Person walks on heel (talipes—clubfoot).  Talipes equinus: Person walks on toes.  Talipes varus: The foot is bent inwards, persons walk on the outer border, and the foot is inverted and adducted.  Talipes valgus: Bent outwards, person walks on inner border of foot, i.e. foot everted and abducted.  Talipes equinovarus: Clubfoot, inverted, adducted and plantar flexed. It is associated with spina bifida.

Fig. 23.2: Deformities of foot

Arches of Foot

217

LAQ-18 Describe lateral longitudinal arch under following heads 1. Functions, 2. Formations of the arch, 3. Factors maintaining arch, and 4. Applied anatomy.

1. Functions: The lateral longitudinal arch is formed by a few bones and joints, therefore, rigidity is more and helps in transmission of weight and thrust. 2. Formations of arch (Fig. 23.3) A. Ends a. Anterior end is formed by cuboid and by the heads of 4th and 5th metatarsal bones. b. Posterior end is formed by lateral part of calcaneum, which is short and strong. B. Summit is formed by articular facet of superior surface of calcaneum. C. Pillar a. Anterior pillar is formed by 4th, 5th metatarsals and cuboid. b. Posterior pillar is formed by lateral 1/2 of the calcaneum. D. Joint involved is calcaneocuboid. E. Classification of joint: Saddle type of synovial joint.

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3

Fig. 23.3: Lateral longitudinal arch of right foot

3. Factors maintaining arch A. Bones: Bones do not play any important role in maintenance of the arch. A lar projection of cuboid, called calcanean angle, occupies the lower part of anterior surface of calcaneum. This bony projection maintains the upward tilt of the long axis of calcaneus.

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B. Tie beam or bow string a. Lateral part of plantar aponeurosis is a main structure acting as tie beam. b. The other structures forming the tie beam are I. Tendons of flexor digitorum longus of the 4th and 5th toes, II. The lateral ½ of flexor digitorum brevis, and III. Abductor digiti minimi. C. Intersegmental tie or staples a. Short plantar ligament is very thick. It fills the concavities of calcaneus and cuboid. b. Long plantar ligament is thin and extends from the heel to both ridges of cuboid. It helps to maintain the concavity of the arch. D. Sling: Peroneus longus by contraction increases the height of lateral longitudinal arch. It is the most important single factor in maintaining its integrity. 4. Applied anatomy

Lower Limb

3

 Absence of arches is called flat foot. It is also called pes planus.  The exaggeration of longitudinal arch of the foot is known as height of pes cavus  The deformities of foot  Clubfoot: A congenital deformity of the foot, which is twisted out of shapes or position.  Talipes calcaneus: Person walks on heel (talipes—Clubfoot).  Talipes equinus: Person walks on toes.  Talipes varus: The foot is bent inwards, persons walk on the outer border, and the foot is inverted and adducted.  Talipes valgus: Bent outwards, person walks on inner border of foot, i.e. foot everted and abducted.  Talipes equinovarus: Clubfoot, inverted, adducted and plantar flexed. It is associated with spina bifida.

4 Upper Limb • Bones of Upper Limb • Pectoral Region • Axilla • Scapular Region • Cutaneous Nerves, Superficial Veins and Lymphatic Drainage • Arm • Forearm and Hand • Joints of Upper Limb

Attention Please All the texts in boxes are not to be written in the examination. The shape of the muscles is drawn only to memorize the word. It may • Signify the meaning of the word. • Match the shape of the muscles in the body • Represent cartoon All the shapes of muscles are not required to be drawn in the examination. All the cartoons are drawn to memorize the subject. They may not have any role in the subject. They are not supposed to be drawn while writing the answer of the question.

24 Bones of Upper Limb

OLA-1

Enumerate the muscles in the upper limb having more than 1 head

1. Pectoralis major (Fig. 24.1A) A. Sternal head, and B. Clavicular head.

Fig. 24.1A: Sternum and right humerus showing attachments of pectoralis major

2. Biceps (Fig. 24.1B) A. Long head, and B. Short head. 3. Triceps (Fig. 24.1C) A. Long head, B. Lateral head, and C. Medial head.

Fig. 24.1B: Humerus and radius of right side showing attachments of biceps brachii

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222

Fig. 24.1C: Posterior surface of scapula, humerus and ulna showing the attachments of triceps

4. Pronator teres (Fig. 24.1D) A. Humeral head, and B. Ulnar head.

Fig. 24.1D: Humerus and radius showing attachments of pronator teres

5. Flexor pollicis longus (Fig. 24.1E) A. Superficial head, and B. Deep head.

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4

Fig. 24.1E: Anterior surface of radius, ulna, carpals and metacarpal showing attachments of flexor pollicis longus

Bones of Upper Limb

OLA-2

223

Enumerate the peculiarities of clavicle

1. Morphologically A. It is only long bone kept horizontally B. Not having a. Three borders, b. Three surfaces, and c. Medullary cavity. C. Pierced by nerves (middle supraclavicular nerve). 2. Development A. Develops from one primary centre and two secondary centres, and B. Ossifies partly in membrane and partly in cartilage. C. First bone to ossify in the body. 3. Transmits the weight from appendicular to axial skeleton. SN-1

Coracoid process

(Kroax—a crow, and -aeidos (Gk) = shape) Introduction: It is a process of a scapula projecting forward and slightly laterally. 1. Evolution: It represents the ventral element of scapula and is homologous to the ischium of hip bone. It is a type of atavistic epiphysis. 2. Attachments (Figs 24.2A to C) A. It gives attachment to following muscles. a. Short head of biceps and coracobrachialis. They are attached to the tip of coracoid process. The coracobrachialis is attached medially and short head of biceps is laterally.

B. It gives attachment to following ligaments. a. Coracohumeral ligament which extends from lateral border of coracoid process to anatomical neck of humerus. b. Coracoacromial ligament: It is attached to coracoid and acromial process of scapula. c. Coracoclavicular ligament: It is a strong band between coracoid process and clavicle. It consists of I. Conoid part: It is vertical lar band. The base is attached to the conoid tubercle of clavicle and apex is attached to the root of the coracoid process, II. Trapezoid part is attached to trapezoid line. d. Costocoracoid ligament: It extends from the coracoid process to the 1st rib. It is a thickening of clavipectoral fascia.

4 Upper Limb

b. Pectoralis minor: It inserts on the superior surface and medial border of the coracoid process.

Exam-Oriented Anatomy

224

Fig. 24.2A and B: The muscles attached to the finger-shaped right coracoid process

Fig. 24.2C: Ligaments attached to coracoid process of scapula

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4

3. Applied anatomy : The weight of upper limb is transmitted from the scapula to the clavicle through coracoclavicular ligament. The weight from the clavicle to the axial skeleton (sternum) is transmitted through sternoclavicular ligament. Note: Coracoid process of scapula is compared with the bent finger. Table 24.1: The ligaments and muscles attached to segments of coracoid process Segments of bent finger

Part of coracoid process

Attachments Ligaments Muscles

• Proximal phalanx

• Proximal vertical part

• Suprascapular

• Middle phalanx

• Middle horizontal part

• CoracoClavicular Humeral Acromal

• Distal phalanx

• Distal oblique part

• Pectoralis minor

• Biceps femoris coracobrachialis

25 Pectoral Region

LAQ-1

Describe mammary gland as under following heads 1. Gross anatomy, 2. Histology, and 3. Applied anatomy.

1. Gross anatomy A. Introduction a. General introduction: It is a modified sweat gland, rudimentary in male , well developed in female after puberty. b. Situation: It is present in the superficial fascia except the tail part which pierces the deep fascia of axilla through foramen of Langer. It is called axillary tail of Spence. c. Extent (Fig. 25.1) I. Vertically: It extends from 2nd to 6th rib. II. Horizontally: It extends from the lateral border of sternum to mid-axillary line.

Fig. 25.1: Deep relations of the right mammary gland and its tail 225

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226

B. External features Structures a. Skin consists of nipple and areola. I. Nipple: It is a blackish, conical projection of skin situated in the 4th intercostal space. It is pierced by 10–15 lactiferous ducts. It contains smooth muscle. II. Areola: It is circular blackish discolouration around the nipple. The colour of the areola is changed after first pregnancy. It contains plenty of modified sebaceous glands. They enlarge during pregnancy and are called tubercles of Montgomery (Fig. 25.2). They secrete oily secretion. It lubricates and prevents cracking of the skin over the nipple. It is devoid of hair and fat.

Fig. 25.2: Tubercles of Montgomery

b. Parenchyma (Fig. 25.3): It consists of I. Glandular part: It consists of alveoli, lactiferous ducts and dilated part called lactiferous sinus, II. Fibrous stroma: It consists of fibrous septa, which extends from skin to the deep fascia and divides gland into 10 to 15 lobes by ligaments of Cooper III. Fatty stroma: It lies between septum and glandular part.

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Fig. 25.3: Structure of the mammary gland

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C. Relations a. Superficial relations are I. Skin, and II. Superficial fascia. b. Deep relations are I. Retromammary space: It is traversed by lymph and blood vessels. II. Pectoral fascia. III. Muscles: The base of the gland rests on the following muscles i. Pectoralis major in medial 2/3rd ii. Serratus anterior in lateral 1/3rd iii. External oblique in inferomedial quadrant. c. Structures deep to above muscles are: Subclavius, clavipectoral fascia, pectoralis minor and suspensory ligament of axilla. D. Blood supply: The mammary gland is extremely vascular. a. Arterial supply I. Major arteries (Fig. 25.4) i. Internal thoracic (mammary) artery  First branch of 1st part of subclavian artery.  It sends branches through intercostal spaces.  It supplies medial 1/2 of the mammary gland.  The branches in the 2nd and 3rd intercostal space are largest. ii. Lateral thoracic artery  It is 2nd branch of 2nd part of axillary artery.  It is the main artery supplying lateral half of the mammary gland.  It curls around the lateral border of pectoralis major.

4 Upper Limb

 It supplies lateral 1/2 of mammary gland.

Fig. 25.4: Major arteries of mammary gland

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Exam-Oriented Anatomy

II. Minor arteries (Fig. 25.5) i. Lateral branches of posterior intercostal arteries  Branch of descending thoracic aorta.  It gives perforating branches which also supply mammary gland. ii. Acromiothoracic  It is 1st branch of 2nd part of axillary artery.  It supplies upper lateral quadrant of the mammary gland.

Fig. 25.5: Minor arteries of mammary gland

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4

b. Venous drainage : The main veins draining the area around areola and glandular tissue are deep veins. These veins run with the corresponding arteries. The veins are I. Internal thoracic vein drains into—subclavian vein. II. Acromiothoracic  III. Superior thoracic  veins drain into—axillary vein. IV. Lateral thoracic  V. Posterior intercostal veins are important link to the internal venous plexus and to the vertebral veins. • Applied anatomy : Apart from the lymphatics, cancer may spread through the regional veins. It is important to know that the veins draining the breast communicate with vertebral venous plexus of veins. Through these communications cancers can spread to the vertebrae and to the brain. E. Nerve supply a. Sensory and sympathetic: 4th to 6th intercostal nerves. b. Hormonal control: I. Oestrogen stimulates duct system. II. Progesterone stimulates the formation of alveoli.

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III. Oestrogen and progesterone are responsible for the formation of true (secretory) alveoli during pregnancy.

IV. Prolactin maintains lactation.

V. Oxytocin helps in ejection of milk. 2. Histology : A. Classification: Mammary is apocrine, modified, tubuloalveolar gland (Fig. 25.6A).

Upper Limb

4 Fig. 25.6A: Histology of mammary gland—inactive stage

B. Microscopy: It consists of a. Glandular tissue which are lined by simple cuboidal epithelium and encloses large lumina. b. Large amount of fibrofatty tissue. c. A duct which is lined by two layers of cuboidal or flattened cells.

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d. In active stage (Fig. 25.6B), I. The secretory cells become low cuboidal. II. Alveoli are distended and filled with milk. III. Lumen contains secretion.

Fig. 25.6B: Histology of mammary gland—active stage

3. Applied anatomy

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4

 Retromammary space: The breast prostheses are usually inserted in this space.  To drain breast abscess, the incision is taken radially. It causes minimum damage to the lactiferous duct.  Applied anatomy of lymphatics  Axillary lymphadenopathy is caused by • Infection of the structures in the anterior wall of the chest. This is one of the common causes of axillary lymphadenopathy. • Carcinoma of breast: This is one of the important causes of axillary lymphadenopathy. In malignant disease of the mammary gland, the axillary lymph nodes are hard, irregular and fixed to the deeper structures.  Lymphatics from upper and lower medial quadrants go to opposite side and, therefore, a tumour arising from the medial 1/2 of mammary gland is dangerous.  Back door exit: The malignant cells may penetrate pectoralis major and go to Reiter’s lymph node. They drain into apical group of axillary lymph nodes.

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231

 Carcinoma usually arises from epithelium of larger ducts.  Suspensory ligaments of Cooper are infiltrated by malignant cells and produce dimples overlying skin.  Peau d’orange is a condition where the hair follicles over the lump appear to be retracted. It is caused by obstruction of the cutaneous lymphatics. The obstruction is caused by stagnation of lymph and oedema of skin around the hair follicles. This resembles the skin of an orange, hence the name (Fig. 25.7).  The cancer cells of lower medial quadrant of breast spread to subdiaphragmatic and hepatic nodes via the subperitoneal lymph plexuses. A few cells may Fig. 25.7: Peau d’orange drop in the peritoneal cavity > the ovary. Secondary deposits through transcoelomic spread are called Krukenberg’s tumours. SN-2

Development of mammary gland

1. Chronological age: It develops in the 6th week of intrauterine life. 2. Germ layer A. Ectoderm, and B. Mesoderm. 3. Site: It develops in the region of milk ridge (Fig. 25.8). It extends from axilla to inguinal region on ventral side of body.

Fig. 25.8: Diagram showing milk ridge

4. Source A. Epithelial lining of duct and alveoli are developed from surface ectoderm. B. Fibrofatty stroma is developed from underlying mesoderm. 5. Anomalies A. Polymastia: Supernumerary breast. B. Amastia: Absence of breast.

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C. Athelia: Absence of nipple. D. Polythelia: Supernumerary nipples. E. Accessory breasts (Fig. 25.9): They are present along milk line. They have been observed in neck, axilla, cheeks, femoral triangle.

Fig. 25.9: Accessory breast in axilla

SN-3

Lymphatic drainage of mammary gland

1. Lymphatic drainage:

A. Lymphatic drainage of mammary gland is important because of the following reasons (Fig. 25.10 and Table 25.1) a. The malignancy of mammary gland is one of the common malignancies

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4

among all malignancies of female . The incidence is more in postmenopausal age. b. It almost spreads to the regional lymph nodes and to the opposite side. c. Early diagnosis has better prognosis. B. Lymph nodes: 75% lymphatics drain into axillary lymph nodes. a. 20% lymphatics drain into internal mammary lymph nodes. b. 5% lymphatics drain into posterior intercostal lymph nodes. C. Superficial and deep of lateral 1/2 of mammary gland drain into anterior group of axillary lymph nodes. They spread to central and apical group of axillary lymph nodes. D. Medial 1/2 is divided into upper medial and lower medial quadrants. E. Nowadays, simpler nomenclature is adapted a. Low nodes (level 1): Below pectoralis minor muscle. b. Medium nodes (level 2): Behind pectoralis minor muscle. c. High node (level 3): Above pectoralis minor muscle.

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233

Fig. 25.10: Lymphatic drainage of right mammary gland Table 25.1: Lymphatic drainage of mammary gland Superficial (except skin over nipple and areola)

• Upper medial • Drains into any one of the following lymph nodes: • Parasternal group of lymph nodes on the same side (which are situated along the internal mammary artery) • Opposite parasternal group of lymph nodes. • Supraclavicular lymph nodes present above the clavicle

Deep (parenchyma and skin over nipple and areola) • Drains into one of following nodes: Apical nodes and internal mammary lymph nodes.

• Lower medial • Drains into any one of the lymph nodes mentioned below: Contd.

4 Upper Limb

Particulars

Exam-Oriented Anatomy

234

Table 25.1: Lymphatic drainage of mammary gland (Contd.) Particulars

Superficial (except skin over nipple and areola)

Deep (parenchyma and skin over nipple and areola)

• Parasternal group of lymph nodes on the same side (which are situated along the internal mammary artery) • Opposite parasternal group of lymph nodes • Drains into lymph node in the rectus sheath •  liver  ovary (Krukenberg’s tumour). • Lateral upper • Anterior axillary group of lymph nodes > Central group of lymph nodes and lateral > Apical group of lymph nodes lower

SN-4

Serratus anterior muscle

1. Attachments A. Proximal attachments a. Upper 8 ribs in the midaxillary plane. b. Fascia covering the intervening intercostal muscle. c. The 1st digitation arises from the 1st and 2nd ribs. d. All other digitations arise from their corresponding ribs. B. Distal attachments: Costal surface of the scapula. I. The first and second digitations are attached on the superior angle. II. The 3rd and 4th digitations form a thin sheet and is attached to the length of the vertebral (medial) border. III. Lowest 4 digitations are attached to the inferior angle. The muscle is covered by a strong well-developed fascia.

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4

2. Nerve supply : A. From roots of brachial plexus—long thoracic nerve (C5, C6, C7) (nerve of Bell or nerve to serratus anterior). B. The muscle is supplied segmentally. a. The fibres of C5 supply 1st and 2nd digitations. b. The fibres of C6 supply 3rd and 4th digitations. c. The fibres of C5 supply 5th to 8th digitations. C. The nerve lies behind the midaxillary line. It is situated behind the lateral branches of the intercostal arteries. It is on the surface of the muscle and deep to the fascia. It is thus protected in operations on the axilla. 3. Action A. The whole muscle contracts as one unit. It protracts the scapula as in punching and pushing, thus effectively elongating the upper limb.

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B. The lower 4 digitations assist trapezius. This is important in rotating the scapula laterally and upwards in raising the arm above the level of the shoulder. In this action, it is a more powerful rotator than trapezius. In all positions, the muscle keeps the vertebral border of the scapula in firm apposition with the chest wall.

Fig. 25.11A and B: Serratus anterior—boxer’s muscle

4. Test: The outstretched hand is pushed against a wall. Paralysis results in ‘winged scapula’ (Refer to Fig. 27.12). The vertebral border becomes prominently raised off the posterior chest wall. 5. Functions A. It keeps the medial border of the scapula in contact with the chest wall. B. It plays an important role in abduction of arm. C. It helps in the elevation of the arm above the horizontal plane. D. It pulls the scapula forward as in throwing, pushing and punching.

SN-5

Nerve to serratus anterior

Introduction: Nerve to serratus anterior is also called long thoracic nerve. 1. Root value A. It arises from posterior aspect of C5, C6 and C7. B. Branches of C5 and C6 enter scalenus medius and unite in the muscle. C. It emerges as a single trunk from its lateral border and passes down into the axilla. D. It is joined by a branch from C7 on the surface of serratus anterior.

4 Upper Limb

6. Effects of injury of long thoracic nerve A. The medial border of the scapula stands out from the chest wall, particularly when the patient is asked to press against the wall in front of him. This condition is known as ‘winged scapula’ (Refer to Fig. 27.12). B. The inability to raise the arm above the head. C. The inability to carry arm forward in breast stroke of swimming, a condition called ‘swimmer’s palsy’. D. The serratus anterior is being the strongest protractor of the arm. It plays the key role in a forward punch during boxing; hence it is often termed ‘Boxer’s muscle’ (Fig. 25.11).

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Exam-Oriented Anatomy

2. Course and relations A. The nerve passes down posterior to the midaxillary line. B. It is behind the lateral branches of intercostal arteries on the surface of muscle. C. It lies deep to the fascia and hence is protected during an operation on the axilla. 3. Distribution A. It supplies serratus anterior segmentally. B. C5 root supplies the fibres of serratus anterior arising from superior angle. C. C6 supplies to the fibres of serratus anterior arising from medial border. D. C7 supplies to the fibres of serratus anterior arising from inferior angle of the scapula. Box 25.1 Thus, the keyword for serratus anterior is “SALT 5,6,7”. The letter “S” of “SALT” indicates “Serratus” The letter “A” of “SALT” represents “Anterior” The letter “L” of “SALT” indicates “Long” The letter “T” of “SALT” means “Thoracic” The digits 5, 6, 7 indicate the root value of the nerve to serratus anterior. Features common to dorsal scapular nerve and nerve to serratus anterior. • Arise from roots of brachial plexus. • Formed in the substance of scalenus medius. • Emerge from various borders of scalenus medius. The dorsal scapular nerve runs on posterior border and the nerve to serratus anterior runs on lateral border of scalenus medius.

Upper Limb

4

Box 25.2 Please do watch animation video of nerve to serratus anterior (BP-10) of 3.42 minutes by scratching the code. 4. Applied anatomy

 The nerve to serratus anterior is commonly injured by a stab injury.  During removal of a breast tumour and during thoracotomy, it may lead to the following effects  Weakening of protraction of scapula.  Inferior angle and medial border of scapula becomes unduly prominent particularly when the patient pushes his hands against the wall. This condition is called winging of the scapula.  In anterolateral or posterolateral thoracotomy, you need to incise the serratus anterior muscle. Care has to be taken to prevent the injury to the nerve to serratus anterior while incising this.

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 Swimmer’s palsy is caused due to paralysis of serratus anterior muscle. It is due to an injury to long thoracic nerve. Injury is caused by friction by scalenus medius muscle. The individual is unable to carry arms forwards in breast stroke of swimming; hence the name "Swimmer's palsy."

Box 25.3 Please do watch the video of animation of “applied anatomy of nerve to serratus anterior” (BP-11) after scratching code. Duration of the video is of 1.38 minutes. SN-6

Suprascapular nerve

1. Root value: C5 and C6. A. It arises from the upper trunk.

Fig. 25.12: Right suprascapular nerve

2. Course and relations It is prominent beneath the fascial floor of lower part of the posterior It can be seen above the clavicle as a large nerve. Leaves upper trunk and passes back and disappears deep to trapezius. Passes through the suprascapular foramen, beneath the suprascapular ligament and supplies supraspinatus. E. Descends laterally to the spine of scapula and supplies infraspinatus, shoulder joint, acromioclavicular joint and scapula.

Box 25.4 At this point, I need to remind you that the suprascapular artery passes above the suprascapular ligament and suprascapular nerve passes below the ligament. This can be remembered easily and permanently by a little analogy: The letter "A” represents an aeroplane and artery. And the letter “N” represents the navy and nerve. So, suprascapular artery passes above the ligament. And suprascapular nerve passes below the ligament.

4 Upper Limb

A. B. C. D.

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238

3. In the supraspinous fossa, it gives A. Two branches to the supraspinatus muscle, and B. Articular filament to the shoulder joint. 4. It runs beneath the supraspinatus. It curves around the lateral border of the spine of the scapula and reach infraspinous fossa. 5. In the infraspinous fossa, it gives A. Two branches to the infraspinatus muscle, B. Articular branch to shoulder joint, and C. Branch to scapula. Box 25.5 Please do watch animation video of nerve suprascapular nerve (BP-10) of 3.42 minutes by scratching the code. SN-7

Nerve to the subclavius

Introduction: The nerve to the subclavius is also called subclavian nerve. 1. Root value: It is a small filament, which arises from the point of junction of the 5th and 6th cervical nerves. 2. Course and relations A. It passes down in front of the lower trunk of brachial plexus and subclavian vessels. B. It enters the posterior surface of subclavius and supplies it and sternoclavicular joint. C. It is usually connected by a filament to the phrenic nerve called accessory phrenic nerve. D. It is to be remembered that the phrenic nerve passes behind the subclavian vessels but the accessory phrenic nerve passes in front of them.

Upper Limb

4

3. Applied anatomy : During operation of phrenic nerve, the accessory nerve may get pulled, if present. The pull of accessory phrenic nerve may cut subclavian vessels. It results in heavy bleeding. Box 25.6 The nerve to subclavius is an important nerve to an unimportant muscle. Box 25.7 Please do watch video of animation of “nerve to subclavius (BP-13”) after scratching the code. The duration is 1.40 minutes SN-8

Trapezius

1. Proximal attachments (Fig. 25.13) A. Medial 1/3rd of superior nuchal line, B. External occipital protuberance,

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239

C. Ligamentum nuchae, D. Spines of C7 to T12 vertebrae, and E. Corresponding supraspinatus ligaments.

Fig. 25.13: Attachments of trapezius

2. Distal attachments A. Upper fibres into the posterior border of lateral 1/3rd of clavicle. B. Middle fibres, a. Medial margin of the acromion, and b. Upper lip of the crest of spine of the scapula. C. Lower fibres, a. Apex of triangular area at the medial end of spine, and b. Intervening bursa. 3. Action A. Upper fibres combine with levator scapulae, and elevate the scapula, as in shrugging. B. Middle fibres combine with rhomboids and retract the scapula.

4. Nerve supply

A. Motor: Spinal part of accessory nerve (Hitchrail nerve) B. Proprioceptive: Branches from C3, C4. SN-9

Pectoralis minor

1. Proximal attachments (Fig. 25.14) A. 3rd, 4th and 5th ribs, near the costochondral junction. B. Intervening fascia covering external intercostal muscles.

4 Upper Limb

C. Upper and lower fibres combine with serratus anterior and rotate the scapula forwards round the chest wall. It plays an important role in abduction of the arm beyond 90° (overhead abduction). D. Steadies the scapula

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240

Fig. 25.14: Attachments of pectoralis minor

2. Distal attachments A. Medial border of the coracoid process. B. Upper surface of the coracoid process. 3. Action A. With serratus anterior, it draws the scapula forward. B. Depresses the shoulder. C. Helps in forced inspiration. 4. Nerve supply

A. Medial pectoral nerves (C8, T1) arise from medial root of brachial plexus. B. Lateral pectoral nerves (C5, C6, C7) arises from lateral root of brachial plexus. 5. Features A. It divides the axillary artery into three parts. a. 1st part is medial to upper border of pectoralis minor, b. 2nd part is deep of pectoralis minor, and c. 3rd part is lateral to lower border of pectoralis minor. B. The cords of brachial plexus in relation to 2nd part of axillary artery. a. Medial cord of brachial plexus lies medial to 2nd part of axillary artery.

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4

b. Lateral cord of brachial plexus lies lateral to 2nd part of axillary artery. c. Posterior cord of brachial plexus lies posterior to 2nd part of axillary artery. SN-10

Pectoralis major

1. Proximal attachments (Fig. 25.15): It is a spiral muscle and has two heads. A. Clavicular head: It arises from medial 1/2 of anterior surface of clavicle. B. Sternocostal head: It arises from a. Lateral part of anterior surface of sternum up to 6th costal cartilage, b. 2nd to 6th costal cartilages, and c. Aponeurosis of external oblique muscle.

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Fig. 25.15: Pectoralis major muscle

2. Distal attachments: By a flat bilaminar tendon (5 cm long) into the lateral lip of bicipital groove of humerus in ‘U’-shaped manner. A. Upper fibres are inserted in lower part of bicipital groove. B. Lower fibres are inserted in upper part of bicipital groove. C. Tendon is twisted by 180° and has two laminae which are described in Table 25.2. Table 25.2: Insertion of anterior and posterior laminae of pectoralis major Posterior lamina

• Thick and shorter

• Thin and longer

• It receives three layers of muscle fibres

• It receives fibres from

Superficial fibres arise from clavicle

– Front of sternum

Middle fibres arise from manubrium Deep fibres arise from margin of sternum and 2nd to 6th rib.

– 2nd to 6th costal cartilage – The fibres form the sternum and aponeurosis are twisted around the lower border of the rest of the muscle. The twisted fibres form the anterior axillary fold. – Aponeurosis of external oblique a and b fibres are twisted.

3. Relations A. Superficial a. Skin b. Superficial fascia c. Mammary gland B. Deep a. Bones and cartilages; I. Sternum II. Costal cartilage III. Ribs b. Clavipectoral fascia

4 Upper Limb

Anterior lamina

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242

c. Muscles I. Subclavius, II. Pectoralis minor, III. Serratus anterior, IV. Intercostals, V. Upper part of biceps brachii, and VI. Coracobrachialis d. Axillary vessels e. Cords of brachial plexus and their branches. 4. Nerve supply

A. Medial pectoral nerve (C8 and T1): It pierces pectoralis minor and supplies the muscle. B. Lateral pectoral nerve (C5, C6 and C7): It pierces clavipectoral fascia. 5. Blood supply: Pectoral branch of thoracoacromial artery. 6. Action (Fig. 25.16) A. The clavicular fibres of pectoralis major combine with the anterior fibres of deltoid and bring flexion of the shoulder joint. B. The sternal fibres of pectoralis major combine with latissimus dorsi and bring adduction and medial rotation of the shoulder joint. C. It is also an accessory muscle of inspiration. D. It is well developed in climbing and flying animals.

Upper Limb

4 Fig. 25.16: Actions of pectoralis major 1. Clavicular part of pectoralis major is active on right side 2. Sternal part of pectoralis major is active on left side

7. Testing of the muscle A. Clavicular fibres are tested by flexing the abducted arm against resistance. B. Sternocostal fibres are tested by adducting the arm against resistance. 8. Anomalies A. Sometimes the sternocostal part of pectoralis major muscle is absent. B. Poland's syndrome: Both pectoralis major and minor are absent. It is associated with absence of breast and 2 to 4 ribs.

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243

9. Applied anatomy : In fracture of clavicle, the contraction of pectoralis major shift the lateral fragment of clavicle below the medial fragment.

Fig. 25.17: Pectoralis major muscle is active in namaste position

SN-11

Clavipectoral fascia

Introduction: It is the strong sheet of deep fascia extending from pectoralis minor to the inferior surface of clavicle. 1. Relations A. Anterior a. Skin, b. Mammary gland, and c. Pectoralis major. B. Posterior: Axillary sheath containing axillary artery C. Medial: Sternum D. Lateral: Coracoid process.

3. Modifications A. Costocoracoid ligament: The fascia thickens along lower border of subclavius between coracoid process and 1st costochondral junction and is called costocoracoid ligament. B. Suspensory ligament of axilla: The part of the fascia below the pectoralis minor.

4 Upper Limb

2. Attachments A. Medially: It fuses with anterior intercostal membrane of upper two intercostal spaces and attaches to the 1st rib (Fig. 25.18A). B. Laterally: It is thick and dense and attaches to the coracoid process (Fig. 25.18B and Table 25.3). C. Above: It splits to enclose subclavius and attaches to the lips of the subclavian groove of clavicle. Its posterior layer has medial and lateral borders. The medial border fuses with deep cervical fascia which connects the omohyoid to clavicle. Its lateral border fuses with the axillary sheath (Fig. 25.18C and Table 25.4). D. Below: It splits to enclose pectoralis minor. It terminates laterally into short head of biceps.

244

Exam-Oriented Anatomy

Fig. 25.18A: Vertical disposition of clavipectoral fascia

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4

Fig. 25.18B: Coronal section of anterior lamina showing modification of right clavipectoral fascia

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245

Table 25.3: Fate of anterior lamina Border

Represen- Features tations by

Attaches to

Fusion with

• Medial

• BD

• 1st rib

• Anterior intercostal membranes of upper two spaces

• Lateral

• AC

• Thick and dense

• Coracoid process • Short head of biceps

• Above

• AB

• Encloses subclavius

• Anterior lamina of subclavian groove

• Below

• CD

• Joins with posterior lamina at lower border of pectoralis minor and continues as suspensory ligament of axilla

• Coracoclavicular ligament • Short head of biceps

Upper Limb

4

Fig. 25.18C: Coronal section of posterior lamina showing modification of right clavipectoral fascia

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246

Table 25.4: Fate of posterior lamina Border

Represen- Features tations by

Attaches to

Fusion with

• Medial

• BD

• 1st rib

• Deep cervical fascia

• Lateral

• AC

• Thick and dense

• Above

• AB

• Encloses subclavius • Anterior lamina and thickens below it. of subclavian • It is called costogroove coracoid ligament

• Below

• CD

• Joins with posterior lamina at lower border of pectoralis minor and continues as suspensory ligament of axilla

• Coracoid process • Axillary sheath

4. Structures piercing A. Passing outwards a. Thoracoacromial artery and its branches, and b. Lateral pectoral nerve. B. Passing inwards (In—vein and lymph) a. Cephalic vein, and b. Lymphatics from I. Infraclavicular nodes, and II. Mammary gland. 5. Action: It acts as a suspensory ligament of axilla and maintains the dome of axilla. 6. Applied anatomy

Upper Limb

4

 The malignant cells of breast may pierce clavipectoral fascia and go to Reiter’s lymph nodes and the apical group of lymph nodes. This is called back-door exit.  It isolates infections in pectoral region.

26 Axilla

OLA-3

Enumerate the muscles acting in raising the arm above the head

1. Serratus anterior, and 2. Trapezius. LAQ-2

Describe axilla under following heads 1. Boundaries, 2. Walls, 3. Contents, and 4. Applied anatomy.

Introduction: It is pyramid part of arm.

shaped area. It is present on the medial side of upper

1. Boundaries (Fig. 26.1) A. Apex is also called cervicoaxillary canal and is formed a. Medially: By outer border of 1st rib. b. Laterally: By superior border of scapula. c. Anteriorly: By posterior surface of clavicle. B. Base is formed by a. Skin, b. Superficial fascia, and c. Deep fascia extending from anterior axillary fold to posterior axillary fold. 2. Walls A. Anterior wall is formed by following structures. a. Superficial layer is formed by pectoralis major. b. Deep layer is formed by subclavius, clavipectoral fascia, pectoralis minor and suspensory ligament of axilla from above downwards. c. Anterior axillary fold is usually the level of 5th rib. 247

248

Exam-Oriented Anatomy

Fig. 26.1: Boundaries of right axilla

Upper Limb

4

B. Posterior wall is formed by a. Subscapularis muscle, b. Latissimus dorsi muscle, and c. Teres major muscle. d. Posterior axillary fold is at lower fold and corresponds to the inferior edge of serratus anterior C. Lateral wall is formed by a. Intertubercular sulcus of the shaft of humerus which contains long head of biceps brachii, and b. Coracobrachialis and short head of biceps. D. Medial wall is broad and formed by a. Upper 4 to 5 ribs and their intercostal muscles, b. Upper part of serratus anterior covered by a strong fascia, c. Long thoracic nerve, and d. Intercostobrachial nerve (T2). 3. Contents of axilla (Fig. 26.2) A. Axillary sheath B. Axillary artery and its branches a. Superior thoracic artery, b. Acromiothoracic artery, c. Lateral thoracic artery, d. Subscapular artery, e. Posterior circumflex humeral artery, and f. Anterior circumflex humeral artery

249

C. Axillary vein and its tributaries, a. Superior thoracic vein, b. Acromiothoracic vein, c. Lateral thoracic vein, d. Subscapular vein, e. Posterior circumflex humeral vein, and f. Anterior circumflex humeral vein D. Cords of brachial plexus and their branches a. Lateral cord and its branches I. Lateral pectoral nerve, II. Lateral root of median nerve, and III. Musculocutaneous nerve b. Medial cord and its branches I. Medial root of median nerve, II. Medial pectoral nerve, III. Medial cutaneous nerve of arm, IV. Medial cutaneous nerve of forearm, and V. Ulnar nerve. c. Posterior cord and its branches I. Upper subscapular, II. Lower subscapular, III. Nerve to latissimus dorsi, IV. Axillary nerve, and V. Radial nerve Note: The two subscapular nerves and the nerve to latissimus dorsi are present on the posterior wall. d. Long thoracic, and e. Intercostobrachial nerves. E. Axillary lymph nodes a. Anterior, b. Posterior, c. Lateral, d. Central, and e. Apical. F. Axillary fat G. Axillary tail of breast H. Muscles a. Proximal part of biceps brachii, and b. Coracobrachialis.

4 Upper Limb

Axilla

Exam-Oriented Anatomy

250

Fig. 26.2: Contents of right axilla

4. Applied anatomy

 Abscess in superficial or deep to clavipectoral fascia. • Edge of anterior axillary fold, or • Deltopectoral groove.  Between the pectoralis major and minor • Deep to pectoralis minor muscle. Here pus would surround vessels and nerves and ascend into neck or may track along the vessels in arm.  Axillary abscess is drained by putting the knife at the base of axilla midway between anterior and posterior axillary fold and move towards on thoracic side.  One should be careful of the relations of vessels while removing lymph nodes. SN-12

Upper Limb

4

Axillary fascial ‘tent’

The axillary fascial ‘tent’: The axillary lymph nodes are enclosed by layers of fascia which resemble a tent lying on its side. This ‘tent’ can be described as follows: 1. Boundaries: A. Anterior wall: Clavipectoral fascia including the pectoralis minor muscle. B. Postero-inferior wall: Deep fascia covering the chest wall upper ribs and intercostal muscles. C. Antero-superior wall: Fascia covering the subclavian vessels. D. Apex: Points upwards and medially where these layers of fascia come into contact with each other. E. Base: Points downwards and laterally and is open. 2. Content: The lymph nodes are enclosed in this fascial ‘tent’. 3. Applied anatomy : Any operation designed for a block dissection of the axillary

lymph nodes should excise the ‘tent’ intact and should not enter the ‘tent’ which may result in the liberation of malignant cells. OLA-4

Name the branches that arise from each of three parts of axillary artery

1. The axillary artery is divided into three parts by pectoralis minor (Fig. 26.3).

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251

First part gives one branch. Second part gives two branches. Third part gives three branches. The branches from each part are A. 1st part (medial to pectoralis minor): Superior thoracic B. 2nd part (deep to pectoralis minor) ABCD a. Acromiothoracic which gives branches as. Acromial, Breast, Clavicular, and Deltoid. b. Lateral thoracic C. 3rd part a. Subscapular, b. Anterior circumflex humeral artery, and c. Posterior circumflex humeral artery.

Fig. 26.3: Branches of axillary artery

SN-13

2nd part of axillary artery

Introduction: It is deep to pectoralis minor. 1. Relations of 2nd part of axillary artery (Fig. 26.4) A. Anterior a. Skin,

Upper Limb

4

Exam-Oriented Anatomy

252

b. Superficial fascia, c. Deep fascia, d. Pectoralis major, and e. Pectoralis minor. B. Posterior a. Posterior cord of brachial plexus, and b. Subscapularis. C. Lateral a. Lateral cord of brachial plexus, and b. Coracobrachialis. D. Medial a. Medial cord of brachial plexus, b. Medial pectoral nerve, and c. Axillary vein.

Upper Limb

4 Fig. 26.4: Relations of 2nd part of axillary artery

2. Branches A. Acromiothoracic artery which gives branches as a. Acromial for acromial part of clavicle, b. Breast to the upper part of mammary gland, c. Clavicular supplies clavicle, and d. Deltoid to deltoid muscle. B. Lateral thoracic which is the main artery of lateral half of mammary gland.

Axilla

LAQ-3

253

Describe axillary artery under following heads 1. Origin, 2. Course and relations, 3. Branches, and 4. Applied anatomy.

Introduction: It is the artery of axilla. 1. Origin: It is the continuation of 3rd part of subclavian artery. Extent: It extends from outer border of 1st rib to the lower border of teres major. 2. Course and relations (Fig. 26.5): Axillary artery is divided into three parts by pectoralis minor muscle (Table 26.1) A. 1st part: Medial to pectoralis minor. B. 2nd part: Deep to pectoralis minor. C. 3rd part: Lateral to pectoralis minor (Refer to Fig. 26.3). Table 26.1: Relations of the axillary artery Posterior

Medial

Lateral

1st

• Medial cord of brachial plexus, • Nerve to serratus anterior, • Serratus anterior, • Ribs, and • Intercostal muscles

• Axillary vein

• Lateral and posterior cord of brachial plexus

2nd • Skin, • Superficial fascia, • Deep fascia, • Pectoralis major, and • Pectoralis minor

• Posterior cord of brachial plexus, and • Subscapularis

• Axillary vein, • Medial cord, and • Medial pectoral nerve

• Coracobrachialis, and lateral cord

3rd • Skin, • Superficial fascia, • Deep fascia • Pectoralis major, and • Medial root of median nerve

• Upper subscapular nerve, • Lower subscapular nerve, • Nerve to latissimus dorsi, • Axillary nerve, and • Radial nerve

• Axillary vein, • Medial cutaneous nerve of arm, • Medial cutaneous nerve of arm of forearm, and • Ulnar nerve

• Coracobrachialis • Median nerve

• Skin • Superficial fascia, • Platysma, • Supraclavicular nerves, • Deep fascia, • Pectoralis major, and • Lateral pectoral nerve

4 Upper Limb

Part Anterior

254

Exam-Oriented Anatomy

Fig. 26.5: Relations of axillary artery and important nerves of upper limb

Clue: Let us understand relations from third part of axillary artery.

Upper Limb

4

A.The branches of the respective cords of brachial plexus are related to the 3rd part of axillary artery. B. The cords of brachial plexus are related to the respective positions of 2nd part of axillary artery. Box 26.1: Refer to Fig. 26.5 of relations of axillary artery with the text below. To get the relations of the cords of brachial plexus to 1st part of axillary artery, one need to understand following things A. Lateral cord lies on the lateral side of 1st part of axillary artery. B. To get the relations of the medial and posterior cords of brachial plexus, one need to a. Rotate the posterior cord and medial cord. b. The rotation should be 90º and in clockwise direction. c. The rotation should be from relations of 2nd part of axillary artery. C. The final position will be: The medial cord is related on the posterior side and posterior cord is related on the lateral side of 1st part of axillary artery.

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255

3. Branches Table 26.2: Branches of the axillary artery and their distribution Part

Branches

Course and relation

Remarks

Area of distribution

1st

• Superior thoracic

• Runs on upper border of pectoralis minor muscle

• Small branch • Anastomoses with internal thoracic upper intercostal

• Supplies mammary gland and pectoralis major and minor muscles

2nd

• Thoracoacromial

• It runs on the

• It pierces clavi-

• Bones: Clavicle,

• Lateral thoracic

• Accompanies lower border of pectoralis minor • It is closely related to anterior group of axillary nodes.

• Mammary gland

• Supplies sternoclavicular joint

• Anastomoses with posterior circumflex humeral

• Forms important anastomosis around the scapula, humerus and shoulder joint • Forms anastomoses with the deltoid branch of profunda brachii artery

• Subscapular • Largest branch of axillary artery circumflex • Scapular • Runs on lower border of subscapularis

pectoral fascia

acromion process of scapula • Muscles: Pectoralis major, deltoid, and subclavius • Joints: Acromioclavicular joint

• Posterior circumflex humeral

It runs at lower border of subscapularis. It accompanies axillary nerve and passes through quadrangular space

It gives descending branch which anastomoses with ascending branch of profunda brachii

• Muscles of quadrangular space and deltoid • Shoulder joint

• Anterior circumflex humeral— ascending branch

It passes laterally in front of the intertubercular sulcus

Anastomoses with posterior circumflex

• Head of humerus and shoulder joint

4. Applied anatomy

 Axillary artery can be effectively compressed against the humerus, along the inner edge of the coracobrachialis.  Axillary artery is likely to rupture during reduction of an old dislocated head of humerus.

4 Upper Limb

3rd

upper border of pectoralis minor

Exam-Oriented Anatomy

256

OLA-5

Axillary lymph nodes

1. Anterior axillary lymph nodes, 2. Lateral axillary lymph nodes, 3. Posterior axillary lymph nodes, 4. Central axillary lymph nodes, and 5. Apical axillary lymph nodes SN-14

Axillary lymph nodes

The lymph nodes of the axilla are described in following ways (Table 26.3 and Fig. 26.6) Table 26.3: Location of axillary lymph nodes Type

Upper Limb

4

Situation

Receives from Drains into • Central

Draining area

• Anterior

• Along inferior • Lateral half border of pectoralis of breast minor

• Drains most of the lymphatic of breast

• Posterior

• Along subscapular • Axillary tail vessels

• Dorsal part of trunk above the iliac crest

• Lateral

• Posteromedial to axillary vein

• Upper limb

• Drains entire upper limb except those accompanying cephalic vein

• Central

• At the base of axilla

• Anterior • Posterior • Lateral

• Apical

• From anterior, posterior and lateral

• Apical

• Apex of axilla medial to axillary vein

• Central

• Supraclavicular lymph nodes> • Subclavian trunk> • On right side > right lymphatic duct and on left side into thoracic duct

• • • •

Drains Upper limb Mammary gland Axillary lymph node

Applied anatomy : Anterior axillary lymph nodes are enlarged in malignancy of lateral ½ of mammary gland.

Axilla

257

Fig. 26.6: Situation of axillary lymph nodes

LAQ-4

Describe brachial plexus under following heads 1. Formation of brachial plexus, 2. Situation, 3. Relations of brachial plexus, 4. Branches, and 5. Applied anatomy.

Box 26.2 Please do watch video of animation of introduction to nerve plexus (BP-1). There are 2 videos of BP-1 of 4.25 minutes and BP-2 of 1.25 minutes.

1. Formation of brachial plexus: It may be fixed by two ways A. Prefixed: The contribution of C4 is large, T2 is often absent. B. Post-fixed: The contribution by T1 is large, C4 is absent and C5 is reduced in size. Box 26.3 Please do watch video of animation after scratching the code on “fixation of brachial plexus (BP-4)”, duration is 1.25 minutes.

4 Upper Limb

Introduction: It is the network of nerves present at the junction of neck and thorax. It supplies the muscles, joints, skin and blood vessels of the anterior wall of thorax, scapular region and upper limb. It is formed by ventral divisions of C5, C6, C7, C8 and T1.

Exam-Oriented Anatomy

258

Fig. 26.7: Roots, trunks, divisions, cords and branches of brachial plexus

Upper Limb

4

2. Location (Fig. 26.7) A. Roots of brachial plexus emerge between the scalenus anterior and scalenus medius muscles. B. Trunks appear in the lower part of posterior of neck. C. Divisions lie behind the clavicle. a. Anterior divisions supply all the muscles present on the ventral part of thorax and upper limb. b. Posterior divisions supply the muscles present on dorsal part of thorax and upper limb. D. The cords are present in axilla. The cords are related to the 2nd part of axillary artery as per their names. The cords give branches around 3rd part of axillary artery. Box 26.4 Please do watch the video of animation of “BP-3 Formation of brachial plexus (2.25 minutes)” and “BP-6 Nomenclature of brachial plexus (1.43 minutes)”

3. Relations of brachial plexus A. Supraclavicular part: It lies above the clavicle. It consists of the roots, branches of roots and trunks of the brachial plexus. B. Retroclavicular part: It lies behind the clavicle. It consists of divisions of brachial plexus. C. Infraclavicular part: It lies below the clavicle. It includes cords and branches of cord.

Axilla

259

Box 26.5 Please do watch the video of animation of “BP-5 Anatomy of brachial plexus (0.50 minutes)”.

4. Branches A. The nerves arising from roots supply the muscles which bring protraction and retraction of shoulder girdle, i.e. a. Nerve to rhomboids (dorsal scapular nerve) (C5), and b. Nerve to serratus anterior (long thoracic) (C5, C6 and C7). Box 26.6 Please do watch the video of animation of “BP-7 Branches of brachial plexus (1.15 minutes)”.

B. Trunks a. Suprascapular nerve (C5 and C6) supplies I. Supraspinatus, II. Infraspinatus, III. Shoulder joint, IV. Acromioclavicular joint, and V. Scapula. b. Nerve to subclavius (C5 and C6) supplies subclavius muscle. Box 26.7 Please do watch the video of animation of “BP-9. Details of each nerve (1.09 minutes)”.

C. Cords: Following are the branches from respective cords. Laila Loves Majnu

Lateral pectoral nerve, Lateral root of median nerve, and Musculocutaneous nerve b. Medial:

The word “medial”

And the branches of the medial cord begin with the letter “M” except ulnar nerve Medial pectoral, Medial root of median nerve, Medial cutaneous nerve of arm, Medial cutaneous nerve of forearm, and Ulnar nerve.

4 Upper Limb

a. Lateral:

Exam-Oriented Anatomy

260

c. Posterior:

RUNAL

RUNAL denotes an acronym for the branches of posterior cord. Radial nerve, Upper subscapular, Nerve to latissimus dorsi, Axillary nerve, and Lower subscapular. Box 26.8 Please do watch the video of animation of “BP-8. Branches from cords and details of nerve (2.07 minutes)”. 5. Applied anatomy

Upper Limb

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 Injury to the brachial plexus can be discussed depending upon the severity, the frequency and on ascertaining whether it is a partial or a total injury.  The most severe injury of brachial plexus is called global brachial plexus birth palsy. It is also called total brachial plexus birth palsy. • It is more severe than Erb’s palsy. Here the upper and lower nerves are stretched.  Next, the most common injury to brachial plexus is by severe traction of an abducted arm in breech delivery.  The partial paralysis of brachial plexus results from shoulder dislocation.  The direct injury to the brachial plexus can result from a stab or gunshot wound.  Horner’s syndrome: It is due to involvement of sympathetic nerve, which is contributed by T1 through white ramus communicans. It usually occurs due to injury at the root of brachial plexus.  Erb’s paralysis: Injury to upper trunk usually at the Erb’s point causes Erb’s paralysis.  Klumpke’s paralysis: Injury to the lower trunk of brachial plexus.  Winging of scapula: Injury to the nerve to serratus anterior.  Claw hand: Injury to the ulnar nerve. SN-15

How does nerve plexus is formed?

1. The lower part of medulla oblongata continues as the spinal cord. 2. A transverse section of the spinal cord shows the grey and the white matters. A. The grey matter has a ventral and a dorsal horn. B. The nerve fibres arising from these horns are known as ventral and dorsal roots of the spinal nerve, respectively. 3. The dorsal roots bear a swelling which is formed by cell bodies of neuron. It is called ‘dorsal root ganglion.’

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4. The dorsal and ventral roots join together to form a spinal nerve of the respective region. A. The body wall is segmentally supplied by the paired spinal nerves. B. Each paired spinal nerve divides into dorsal and ventral primary rami. C. A posterior longitudinal strip is supplied by dorsal rami. D. A lateral longitudinal strip is supplied by lateral branches of ventral rami. E. And an anterior strip is supplied by the anterior terminal branches of ventral rami. 5. In the foetus, the limb buds grow out of the lateral strip. 6. They are supplied by the lateral branches of the anterior rami. 7. These lateral branches, by their anterior and posterior divisions, form the plexuses and supply the muscles and skin of the limbs. Box 26.9 To be remembered A. Dorsal rami never ever form plexus or plexuses, and B. Plexuses are not formed in thoracic region. Box 26.10 Please do watch the video of animation of “BP-1. Introduction of brachial plexus (4.25 minutes)”.

OLA-6

What is brachial plexus?

Definition of brachial plexus: It is the network of nerves present at the junction of neck and thorax. 1. It supplies all the muscles of upper limb, except trapezius and levator scapulae. 3. It also supplies skin of upper limb except an area just above the point of the shoulder which is supplied by the supraclavicular nerves and the dorsal scapular area. Box 26.11 Please do watch the video of animation of “BP-2 objectives of video (1.25 minutes)” OLA-7

What is prefixed and post-fixed brachial plexus?

Brachial plexus may be fixed in two ways: 1. Prefixed, and 2. Post-fixed. The origin of plexus may shift, i.e. one segment either upwards or downwards, resulting in a prefixed or post-fixed brachial plexus, respectively.

4 Upper Limb

2. It supplies all joints of upper limb.

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Exam-Oriented Anatomy

1. In the prefixed plexus, A. The contribution by C4 is large, B. The contribution by T1 is reduced, and C. T2 is absent. 2. In the post-fixed brachial plexus, A. C4 is absent, B. The contribution by C5 is reduced C. T1 is large, and D. T2 is always present. Box 26.12 Please do watch the video of animation of “BP-4 Fixation of brachial plexus (1.25 minutes)” SN-16

What are the components of brachial plexus?

1. It has four basic components. They are roots, trunks, divisions and cords. 2. It is remembered by the key word RTDC. Box 26.13 It is a short form of Rajasthan Tourist Development Corporation.

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4

These components are compared to those of a tree. 3. Like a tree, the brachial plexus has roots, trunk, divisions, cords and branches. 4. There are only three roots. They are A. Roots of spinal nerve, B. Roots of brachial plexus, and C. Roots of median nerve. 5. The roots of spinal nerve are the ventral and dorsal roots. 6. The roots of brachial plexus are formed by ventral rami of 5, 6, 7, 8 cervical and 1st thoracic spinal nerves. The roots of median nerve are branches of medial and lateral cords of brachial plexus. A. The most caudal root of a brachial plexus is T1 root. B. It is distributed entirely to the flexor compartment of the upper limb. 7. The central root of brachial plexus is C7 and it supplies flexor surfaces of middle 3 fingers of the hand.

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Box 26.14 Please do watch the video of animation of “BP-3 Formation of brachial plexus (2.25 minutes)”. OLA-8

What are parts of brachial plexus?

It has a supraclavicular, a retroclavicular and an infraclavicular part. 1. Supraclavicular part includes roots and trunks. They lie above the clavicle. 2. Retroclavicular part includes divisions, lies behind the clavicle. 3. Infraclavicular part includes cords and branches lies below the clavicle. Box 26.15 Please do watch the video of animation of “BP-5. Anatomy of brachial plexus (0.50 minutes)”. OLA-9

Nomenclature of brachial plexus

1. Trunks are named depending upon the position in the lower part of posterior neck.

of

A. Upper trunk runs in the upper part of posterior of neck, B. Middle trunk is present in the middle part, and C. Lower trunk lies in the lower part of posterior 2. The divisions of the brachial plexus are named on the basis of distribution of the muscles of these branches. A. The branches of anterior division supply all the flexor muscles of upper limb. B. The branches of posterior division supply all the extensor muscles of upper limb.

A. The medial cord lies on the medial side of 2nd part of axillary artery. B. The lateral cord lies on the lateral side of 2nd part of axillary artery. 4. The posterior cord lies on the posterior side of 2nd part of axillary artery. Box 26.16 Please do watch the video of animation of “BP-6. Nomenclature of brachial plexus (1.43 minutes)”

OLA-10 Branches of roots, and trunks of brachial plexus

Branches of roots, and trunks of brachial plexus

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3. The names given to cords of brachial plexus depend upon their relations with the 2nd part of axillary artery.

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Exam-Oriented Anatomy

1. Branches from roots A. The branches arising from roots are called R1 and R2. a. R1 is dorsal scapular nerve which is also called nerve to the rhomboids. b. R2 is a long thoracic nerve which is also called nerve to the serratus anterior (nerve of Bell). B. These nerves supply the muscles which act on pectoral girdle. 2. Branches from trunks, only from upper trunk. These are A. Suprascapular nerve, and B. Nerve to the subclavius. Note: Both have the same root value as C5 and C6. Box 26.17 Please do watch the video of animation of “BP-7. Branches of brachial plexus (1.15 minutes)”. OLA-11 Branches of cords of brachial plexus

Following are the branches from cords. 1. The branches from lateral cord are: A. Lateral pectoral, B. Lateral root of median nerve, and C. Musculocutaneous nerve. Box 26.18 They can be remembered by the first letters of a phrase, Laila Loves Majnu, wherein

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The letter “L” of “Laila” represents “Lateral cord”. The letter “L” of “Loves” represents “Lateral root of median nerve”. The letter “M” of “Majnu” represents “Musculocutaneous nerve”.

2. The medial cord gives 5 branches. They are A. Medial pectoral, B. Medial root of median nerve, C. Medial cutaneous nerve of arm, D. Medial cutaneous nerve of forearm, and E. Ulnar nerve. Box 26.19 It is very interesting to note here that the 1st letter of the words “Medial cord” and the 1st letter of all the branches of medial cord begins with the alphabet “M.” The ulnar nerve is the only exception

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3. The posterior cord gives 5 branches. Box 26.20 The word “RUNAL” is an acronym for the branches of posterior cord.

The letter “R” stands for Radial, The letter “U” stands for Upper subscapular, The letter “N” stands for Nerve to latissimus dorsi, The letter “A” stands for Axillary, and The letter “L” stands for Lower subscapular Box 26.21 Please do watch the video of animation of “BP-8 Branches from cords and details of nerve (2.07 minutes)”. OLA-12 Dorsal scapular nerve

Dorsal scapular nerve is also called nerve to the rhomboids. 1. 2. 3. 4.

It arises in the neck from the posterior aspect of C5 root of brachial plexus. It passes through scalenus medius, runs down deep to levator scapulae. It supplies levator scapulae and lies on the serratus posterior superior muscle. It runs here on the medial side of the descending branch of the transverse cervical artery. 5. It supplies the rhomboid major and minor on the deep surface. Box 26.22 Please do watch the video of animation of “BP-9. Details of each nerve (1.09 minutes)”. OLA-13 Branches of lateral cord of brachial plexus

Box 26.23 This piece of information is important while answering some of the most frequently asked MCQs on the upper limb.

E. It has a communicating branch to the medial pectoral nerve. F. The branch crosses in front of 1st part of axillary artery, and supplies pectoralis minor.

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Lateral pectoral nerve A. It arises from lateral cord. B. It supplies pectoral muscles. C. The root value is cervical 5, 6, and 7. D. It pierces clavipectoral fascia from inside out and supplies the pectoralis major muscle.

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Box 26.24 Also keep in mind that the lateral pectoral nerve does not have a cutaneous branch. Box 26.25 Please do watch the video of animation of “BP-14. Branches of lateral cord (1.20 minutes)”. SN-17

Horner’s syndrome

Box 26.26 It is Claude Bernard-Horner syndrome or is also known as oculosympathetic palsy. This is one of the most important and frequently asked topics in anatomy, surgery and ophthalmology examination.

1. It involves cranial and sympathetic nerves. 2. The sympathetic contribution is from 1st thoracic spinal nerve. 3. It usually occurs due to injury to the root of brachial plexus. Box 26.27 The letters of the word “HORNER“ can act as an acronym to remember the clinical manifestations of Horner’s syndrome.

The letter “H” of Horner signifies Hypohydrosis. It means decreased sweating on the same side of face. A. The letter “O” of Horner indicates loss of Opening of eye. Opening is impossible due to ptosis (drooping of the upper eyelid).

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It is caused by loss of sympathetic innervation to the superior tarsal muscle or Müller’s muscle (smooth muscle of levator palpebrae superioris). In fact, it is pseudoptosis. B. The letter “R” of HORNER should remind us of 3 “Rs”. a. Robertson pupil. It is constriction of the pupil due to paralysis of dilator pupillae muscle. It is due to unopposed action of sphincter pupillae. b. The second “R” stands for loss of visual. c. The third “R” stands for Redness of conjunctiva. C. The letter “N” of HORNER signifies Narrowing of palpebral fissure due to drooping of upper eyelid. D. The letter “E” of Horner stands for Elevation of lower eyelid. E. The last letter “R” of HORNER stands for Retraction or sinking of eyeball which is due to paralysis of orbitalis muscle. It indicates a problem with the sympathetic nervous system, a part of the autonomic nervous system.

Axilla

SN-18

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Erb’s paralysis

Introduction: It is the most common type of birth paralysis. It is a form of brachial plexus palsy. It is Wilhelm Erb who 1st described this condition. 1. Erb’s point: Injury occurring at Erb’s point is called Erb’s paralysis. The junction of 6 nerves is called Erb’s point (Fig. 26.8). The following are the nerves contributing in the formation of A. Ventral division of 5th cervical nerve, B. Ventral division of 6th cervical nerve, C. Suprascapular nerve, D. Nerve to subclavius, E. Anterior division of upper trunk, and F. Posterior division of upper trunk. 2. Site of injury: Injury to upper trunk usually at the Erb’s point causes Erb’s paralysis. 3. Incidence: 1:1000 vaginal deliveries. It is often caused when an infant’s neck is stretched to the side during a difficult delivery.

Fig. 26.8: Erb’s point

4 Upper Limb

4. Causes of injury: A. The most common cause of Erb’s palsy is shoulder dystocia, an abnormal or difficult labour or childbirth (Fig. 26.9A). a. Approximately 45% of Erb’s palsies are associated with shoulder dystocia. b. It can occur if the infant’s head and neck are pulled towards the side, as the shoulders pass through the birth canal. c. The condition can also be caused by I. Excessive pulling on the shoulders during a cephalic presentation, i.e. delivery where, head is delivered first, or II. By pressure on the raised arms during a breech i.e. delivery where feet are delivered first. B. It can also result in neonates affected by the fracture of a clavicle. C. Injury may be due to direct trauma. It includes a. Gunshot wounds, and b. Traction on the arm, or a c. Person falling on the shoulder (Fig. 26.9B).

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Fig. 26.9A: Erb’s paralysis due to birth injury

Fig. 26.9B: Injury due to falling on the shoulder

5. Muscles paralysed: The muscles paralysed in Erb’s palsy can be recollected by the mnemonics. Damaged brachial plexus should be treated intelligently Deltoid, Latissimus Dorsi, Biceps, Supraspinatus, Subscapularis, Brachialis, Teres major and Teres minor, and Infraspinatus (Table 26.4). Table 26.4: Affected nerves, muscles paralysed and the clinical manifestations of Erb’s paralysis Trunk

Nerves

Muscle

Clinical features

• Upper trunk • C5 and C6

• Suprascapular

• Supraspinatus, infraspinatus

• Position of arm • Hangs by the side

• Lateral cord

• Musculocutaneous

• Biceps, Brachialis, • Coracobrachialis • Subscapularis, teres major

• Adducted • Medially rotated forearm extended and pronated

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4

• Upper subscapular • Lower subscapular }

• Posterior cord

• Nerve to latissimus dorsi • Latissimus dorsi • Axillary nerve • Deltoid, teres minor

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Box 26.28 Reasoning out of the position of upper limb in Erb’s palsy. • There are no nerves from ventral rami of C5 and C6. • Suprascapular nerve arises from upper trunk. It innervates supraspinatus and infraspinatus.  Supraspinatus is an initial abductor of shoulder joint. Paralysis of this muscle keeps the upper limb adducted.  The infraspinatus is a lateral rotator. Paralysis of this keeps hands in medial rotation. • The lateral and posterior cords are involved.  The musculocutaneous nerve arises from lateral cord.  Paralysis of this nerve results in loss of flexion of elbow. As a result, the arm is kept in extended position.  The biceps are also a strong supinator. This results in pronated forearm. • The branches of posterior cord are upper subscapular, lower subscapular, nerve to latissimus dorsi, axillary nerve and radial nerve.  The upper and lower subscapular nerve supplies subscapularis. They are medial rotators.  Nerve to latissimus dorsi which, as the name suggests, supplies latissimus dorsi which is also a medial rotator and adductor of shoulder joint.  The ulnar nerve supplies all the small muscles of hand.  It would be wise to note here that the pectoral is the only muscle supplied by all five segments of brachial plexus.  It thus serves as a useful guide to localize the extent of lesion. • Also remember, there is a loss of sensation on the lateral side of arm and forearm. This deformity is described as the ‘Policeman tip.’ Klumpke’s paralysis

Introduction: It is due to the injury of lower roots, i.e. C8 and T1 of brachial plexus (Fig. 26.10A). 1. Site of injury: Lower trunk of the brachial plexus. 2. Cause A. It is caused by breech delivery, where the arm remains above the head, causing birth injury. B. Undue abduction of the arm. This occurs, as the person clasps something with the hands after a fall from a height (Fig. 26.10B). 3. Effect A. There is a sensory loss on the medial side of the forearm. B. The small muscles of the hand leading to claw hands are affected. Patient is not able to extend the fingers. 4. Nerve roots involved: Mainly T1 and partly C8. 5. Muscles paralysed A. Intrinsic muscles of the hand (T1), and B. Ulnar flexors of the wrist and fingers (C8).

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SN-19

Exam-Oriented Anatomy

270

Fig. 26.10A: Klumpke’s paralysis

Fig. 26.10B: Klumpke’s paralysis due to falling from the height

6. Deformity and position of the hand A. Claw hand due to the unopposed action of the long flexors and extensors of the fingers. There is hyperextension at the metacarpophalangeal joints and flexion at the interphalangeal joints. B. Disability a. Complete clawhand b. Cutaneous anaesthesia and analgesia in a narrow zone along the ulnar border of the forearm and hand. C. Horner’s syndrome results in lesion of 1st thoracic sympathetic ganglion. There is injury of T1 nerve proximal to white ramus communicans. The clinical manifestations are ptosis, miosis, anhidrosis, enophthalmos, and loss of ciliospinal reflex. D. Vasomotor changes: The skin area with sensory loss is warmer due to arteriolar dilation.

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E. Trophic changes: Long-standing case of paralysis leads to dry and scaly skin. The nails crack easily with atrophy of the pulp of fingers. 7. Surgical approach: The C8 and T1 nerve is approached by exposing A. The supraclavicular part B. The infraclavicular part A. The supraclavicular part can be exposed in the angle between sternocleidomastoid and the clavicle. a. The inferior belly of omohyoid and lateral branches of thyrocervical trunk are divided. b. The roots of the plexus are identified behind the scalenus anterior. c. They need to be retracted to visualize the lower trunk. d. Care should be taken to avoid damage to the phrenic nerve. B. To expose the infraclavicular part,

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a. The deltopectoral groove is opened up. b. The pectoralis minor is detached from the coracoid process. c. The plexus and branches around the axillary artery can be dissected out from axillary sheath. d. The middle part of the clavicle may have to be removed, if more proximal exposure is needed. OLA-14 Cervical rib

Introduction: A supernumerary rib arising from cervical vertebra. It usually arises from 7th cervical vertebra. 1. Synonymous: Costa cervicalis. 2. Effect of cervical rib: It presses the lower trunk of brachial plexus (C8, T1). 3. Applied anatomy

 Cervical rib may compress the subclavian artery. This causes thrombi which are thrown as emboli in the vessels of the limb.  They bring about vascular changes in the arm. It results in paraesthesia along the ulnar border of the arm and weakness and wasting of small muscles of hand.  A cervical rib may elevate the subclavian artery and render it unduly palpable. It simulates an aneurysm.  In fact, there may be aneurysmal dilation of the artery distal to the edge of the cervical rib. OLA-15 Sprengel’s deformity

Sprengel’s deformity of the scapula (congenital high scapula) 1. Cause: Failure of descent of scapula leads to Sprengel’s deformity. 2. Clinical manifestation B. An attempt to bring down scapula by a surgical procedure may cause injury to the brachial plexus. OLA-16 Nerve injuries of upper limb

DR CUMA Wrist Drop—Radial nerve injury Claw hand—Ulnar nerve Ape Hand—Median nerve Winging of scapula—Nerve to serratus anterior

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A. The scapula is hypoplastic and situated in the neck region.

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Table 26.5: Causes of lesion of roots and cords of brachial plexus, muscles paralysed and clinical features

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4

Particular

Cause

• Roots of brachial plexus

• During mastectomy operation

• Lateral cord

• Medial cord

Muscles paralysed

Nerve

Clinical features

• Serratus anterior

• Nerve to serratus anterior

• Winging of scapula

• Dislocation of humerus

• Coracobrachialis, biceps

• Musculocutaneous and lateral root of median nerve

• Mid prone forearm • Loss of flexion of forearm and wrist • Sensory loss on the radial side of forearm

• Subcoracoid dislocation of humerus

• Flexor carpi ulnaris • Medial half of flexor digitorum profundus • Abductor digiti minimi • Flexor digiti minimi • Palmar and dorsal interossei • 3rd and 4th lumbricals

• Ulnar nerve

• Medial claw hand • Sensory loss on the ulnar side of forearm and hand.

• Lateral half of flexor digitorum profundus, • Abductor pollicis • Flexor pollicis brevis superficial head • Opponens pollicis • 1st and 2nd lumbricals

• Medial root • Lateral claw of median hand nerve.

27 Scapular Region

OLA-17 Actions of deltoid muscle and its nerve supply

1. Actions A. Anterior fibres are flexors and medial rotator, B. Middle fibres are abductors, and C. Posterior fibres are extensor and lateral rotator. 2. Nerve supply : Axillary nerve (circumflex nerve)—ventral rami of C5–C8 and T1 SN-20

Deltoid

Introduction: It is a

lar, multipennate muscle present in the shoulder region

1. Morphology, attachments and actions (Table 27.1 and Fig. 27.1) Table 27.1: Morphology, attachments, and actions of different fibres of deltoid Particulars

Anterior

Middle

Posterior

Synonymous Type of fibres Range of movement Force of pull

Clavicular Long and parallel More Less

Acromial Multipennate Less More

Scapular Long and parallel More Less

Proximal attachments

Anterior and upper surface of lateral 1/3rd of clavicle

Lateral border of acromion process of scapula

Lower lip of crest of spine of scapula

Distal attachments

Deltoid tuberosity on a V-shaped impression extending on lateral surface of middle 1/3 rd of shaft of humerus.

Actions

Anterior fibres are flexors and medial rotators of shoulder joint

273

Middle fibres are strong abductors of shoulder joint from 15º to 120 º

Posterior fibres are extensors and lateral rotators of shoulder joint

Exam-Oriented Anatomy

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Fig. 27.1: The origin, insertion and morphology of the deltoid muscle

2. Nerve supply Axillary nerve: C5 and C6 of posterior cord of brachial plexus (Fig. 27.2)

Upper Limb

4 Fig. 27.2: Nerve supply of deltoid

3. Structures under cover of deltoid A. Bones a. Upper end of humerus with I. Greater and II. Lesser tubercles,

Scapular Region

B.

C.

D. E.

F.

275

III. Intertubercular sulcus, IV. Upper part of shaft, and V. Surgical neck of humerus. b. Coracoid process of scapula. Muscles attached to a. Greater tubercle I. Supraspinatus, II. Infraspinatus, and III. Teres minor. b. Glenoid cavity I. Supraglenoid tubercle: Long head of biceps, II. Infraglenoid tubercle: Long head of triceps. Vessels a. Anterior circumflex humeral, and b. Posterior circumflex humeral. Nerve: Axillary. Joints and ligaments a. Shoulder joint, and b. Coracoacromial ligaments. Bursae: a. Subacromial and b. Subdeltoid bursae, and c. Bursae of shoulder joint.

4. Applied anatomy

SAQ-1

Rotator cuff

Introduction: It is musculotendinous cuff of shoulder joint. This is a fibrous sheath formed by 4 flattened tendons, namely (Fig. 27.4)

4 Upper Limb

 Fracture of surgical neck of humerus causes lesion of the axillary nerve. It results in paralysis of deltoid. This affects the movement of shoulder joint especially abduction from 15º to 90º.  Paralysis of deltoid results into loss of rounded contour of shoulder region.  In complete axillary nerve lesions, there is complete irreversible deltoid palsy.  With a functioning rotator cuff but poor deltoid, the arm is functionally adept (proficient) and useful Fig. 27.3: Area of anaesthesia (Fig. 27.3). due to lesion of axillary nerve

276

Exam-Oriented Anatomy

Fig. 27.4: Rotator cuff of the shoulder

A. B. C. D.

Supraspinatus, Infraspinatus, Teres minor, and Subscapularis and lateral part of capsule of shoulder joint.

Upper Limb

4 Fig. 27.5: Rotator cuff of right shoulder joint shown by the finger of dorsal surface of right hand

1. Features: S Sits on tuberosities, Sticks to capsule of shoulder joint, Steadies head of humerus, and Strengthens the capsule.

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2. Applied anatomy

 Dislocation of the shoulder joint is more commonly in a downward direction because the capsule is lax inferiorly. SAQ-2

Quadrangular space

Introduction: It is an intermuscular space present in the axilla. It provides a passage between axilla and posterior scapular and deltoid region. 1. Boundaries (Fig. 27.6) A. Above (from anterior to posterior): a. Subscapularis in front, b. Capsule of the shoulder joint, and c. Teres minor behind. B. Below: Teres major. C. Medial: Long head of the triceps. D. Lateral: Surgical neck of the humerus.

Fig. 27.6: Boundaries of muscular spaces and contents of quadrangular space (posterior view)

2. Structures passing A. Axillary nerve, and B. Posterior circumflex humeral vessels. 3. Applied anatomy

 Fracture of surgical neck of humerus causes lesion of axillary nerve leading to paralysis of deltoid muscle.

Upper Limb

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Exam-Oriented Anatomy

278

SAQ-3

Upper triangular space

Introduction: It is an upper intermuscular lar space present in the axilla. It is an area of communication between axilla and posterior scapular region. 1. Boundaries (Fig. 27.7) A. Above: Teres minor B. Below: Teres major C. Lateral: Long head of the triceps D. Apex: Lateral border of scapula where teres major and minor muscles converge.

Fig. 27.7: Boundaries and contents of upper triangular space (posterior view)

Upper Limb

4

2. Structures passing: Circumflex scapular artery, branch of subscapular artery. It pierces the origin of the teres minor and reaches the infraspinatus fossa to anastomose with the suprascapular artery. 3. Applied anatomy

The circumflex scapular artery anastomoses with descending branch of transverse cervical artery and forms important anastomosis around the scapula. SAQ-4

Lower triangular space

Introduction: It is a lower intermuscular 1. Boundaries (Fig. 27.8) A. Medially by long head of the triceps, B. Laterally by shaft of humerus, and C. Above by teres major.

lar space present in the axilla.

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279

Fig. 27.8: Boundaries and contents of lower triangular space (posterior view)

2. Structures passing A. Radial nerve, and B. Profunda brachii vessels. 3. Applied anatomy : Fracture of middle 1/3rd of humerus causes injury to radial

nerve and results in wrist drop. OLA-18 Name the muscles supplied by axillary nerve

1. Deltoid, and 2. Teres minor.

1. Damage of axillary nerve is checked. 2. By testing the sensations over lower lateral part of skin of deltoid. LAQ-5

Describe axillary nerve under following heads 1. Root value, 2. Course and relations, 3. Branches, and 4. Applied anatomy.

Introduction: It is one of the two terminal branches of posterior cord of brachial plexus. Synonymous: Circumflex nerve.

4 Upper Limb

OLA-19 A ten-year-old girl fractures her humerus at the surgical neck. What damage would you check for and how?

280

Exam-Oriented Anatomy

1. Root value: Ventral rami of C5 and C6. Peculiarities A. Posterior division of axillary nerve bears pseudoganglion. (It is thickening of nerve. It simulates ganglion. It does not have cell bodies.) B. Axillary nerve is the ideal example of Hilton’s law, i.e. the nerve supplying the muscles acting on the joint supplies the joint and skin over the joint. 2. Course and relations: It arises from posterior cord of brachial plexus. The posterior cord lies posterior to the 2nd part of axillary artery. The axillary nerve lies posterior to 3rd part of axillary artery (Fig. 27.9). A. In axilla: Despite its name, it supplies nothing in the axilla. a. Its origin is higher than what is usually imagined. b. First, it lies lateral to radial nerve and anterior to subscapularis. c. At the lower border of subscapularis, it curves posterior, inferior to capsule of shoulder joint. d. It enters the quadrangular space.

Upper Limb

4

Fig. 27.9: Relations of axillary nerve

B. In quadrangular space a. The relations of axillary nerve in quadrangular space are I. Subscapularis above and anterior II. Teres minor above and posterior and III. Teres major below, IV. Long head of triceps medially, and V. Surgical neck of humerus laterally. In quadrangular space, posterior circumflex humeral artery is below it. It is accompanied by venae comitantes. The nerve divides into anterior and posterior division. b. Anterior division is accompanied by posterior circumflex humeral artery (branch of 3rd part of axillary artery). They curve round the neck of humerus.

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They run deep to deltoid muscle and supplies deltoid and skin over its anterior part of deltoid muscle. c. Posterior division supplies teres minor which bears pseudoganglion. It also supplies posterior part of deltoid muscle. It pierces deep fascia to become upper lateral cutaneous nerve of arm. ULCN Refer to Fig. 27.8A and 27.8B C. It emerges at the back of the axilla below teres minor. 3. Branches and distribution (Fig. 27.10) A. Muscular a. Deltoid from both divisions. b. Teres minor from posterior division. B. Cutaneous: Upper lateral cutaneous nerve of arm arises from posterior division of axillary nerve and supplies skin over a. Posterior border of deltoid, and b. Upper part of long head of triceps. C. Articular branch to shoulder joint arises from trunk of the axillary nerve. D. Vascular branch to posterior circumflex humeral artery arises from anterior division.

Upper Limb

4

Fig. 27.10: Branches of the axillary nerve from trunk and divisions 1. The symbol “

” at the end of nerve signifies the articular branch

2. The symbol “ ” at the end of nerve signifies the cutaneous branch

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4. Applied anatomy

 Axillary nerve and neurovascular structures are damaged in fracture of surgical neck of humerus.  The axillary nerve is damaged in dislocation of shoulder. The incidence is about 5%. – The other causes of the lesion of axillary nerve are  Fracture of upper end of humerus,  Injection at rounded contour of deltoid.  Damage of axillary nerve results into – Loss of roundness of shoulder, – Prominence of greater tubercle of humerus, – Loss of abduction of shoulder joint, – Overhead abduction of shoulder joint is prevented by reflex inhibition of deltoid through axillary nerve (Hilton’s law), and – Loss of sensations of the skin over lower half of deltoid. Box 27.1 a. It is, therefore, called ULC nerve (upper lateral cutaneous nerve of arm). SN-21

Movements of the pectoral girdle

Introduction: Movements of the acromioclavicular and sternoclavicular joint are always associated with the movement of the scapula.

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1. Movements: The movements of the scapula may or may not be associated with the movements of the shoulder joint. The various movements are described as follows (Fig. 27.11): A. Elevation (shrugging the shoulders): It is associated with the raising of the acromioclavicular joint and depression of sternoclavicular joint. Muscles bringing the movements a. Upper fibres of trapezius, and b. Levator scapulae. B. Depression (drooping of the shoulder): It is associated with depression of acromioclavicular joint and elevation of sternoclavicular joint. Factors bringing the movements a. Gravity, b. Muscles I. Lower fibres of the serratus anterior, and II. Pectoralis minor. C. Protraction (as in pushing and punching movement): It is associated with the forward movement of lateral end and backward movement of the medial end of the clavicle.

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283

Muscles bringing the movements a. Serratus anterior, and b. Pectoralis minor. D. Retraction of the scapula (squaring of the shoulder): It is associated with the backward movement of the lateral end and forward movement of the medial end of the clavicle. Muscles bringing the movements a. Rhomboids major and minor, and b. Trapezius. E. Forward rotation of the scapula round the chest wall takes place during overhead abduction of the arm. The scapula rotates round the coracoclavicular ligament. Muscles bringing the movements a. Upper fibres of trapezius, and b. Lower fibres of serratus anterior. F. Backward rotation of the scapula occurs under the influence of gravity. Muscles bringing the movements a. Levator scapulae, and b. Rhomboids.

Fig. 27.11: Movement of the pectoral girdle

SN-22

Winging of Scapula

1. Definition: It is deformity of the scapula. When the arm is raised, the medial border and inferior angle of the scapula is pulled away from the posterior thoracic wall. The scapula looks like a wing. Hence, it is called winged scapula or winging of scapula.

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284

2. Nerve damaged A. Nerve to serratus anterior (C5, C6, C7), and B. Scapular instabilities may injure the spinal accessory nerve. 3. Weakness of the serratus anterior may arise from A. Damage to the long thoracic nerve, B. Injury to the brachial plexus, C. Viral infection of the 5th, 6th and 7th cervical nerve roots, and D. Certain types of muscular dystrophy. 4. Causes A. Due to trauma a. When the limbs are elevated, as in a knife fight, the nerve is especially vulnerable, b. Weapons, including bullet directed towards the thorax, are a common source of injury, c. Shoulder or neck injuries, d. Carrying load on the shoulder, B. Due to infection: Viral illnesses or toxoid injections, and C. Due to surgical intervention: The nerve may be injured during surgical removal of axillary lymph nodes. 5. Clinical features A. Damage leads to winging of the scapula (Fig. 27.12). Winging of the scapula causes asymmetry of the shoulders. B. It may not be obvious until the patient tries to contract the serratus anterior against resistance. C. It is displayed by asking the patient to push forwards against a wall. D. The patient, therefore, experiences difficulty to raise the arm above the head. E. Damage to the nerve to serratus anterior unable the swimmer to carry arm forward in breast stroke of swimming, it is called ‘swimmer’s palsy’. 6. Prognosis A. There is spontaneous recovery. It may take a year or longer time. B. There is little or no recovery in direct injury of the nerve or division of the nerve.

Upper Limb

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Exam-Oriented Anatomy

Fig. 27.12: Winging of scapula

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285

7. Treatment A. Disability is usually slight and is best accepted. B. If function is markedly impaired, the scapula can be stabilized by tendon transfer. SN-23

Ape thumb deformity

Ape thumb deformity A. Ape—monkey without tail, e.g. gorilla, chimpanzee, orangutan, gibbons (Fig. 27.13A).

Fig. 27.13B: Ape hand 1. Adduction of thumb 2. Lateral rotation of thumb 3. Wasting of muscles of the thenar eminence

Fig. 27.13C: Slowly closing of the fist. The index and middle fingers tend to leg behind the ring and little finger

B. Ape hand—hand with the thumb permanently extended (Fig. 27.13B and C). C. Injuries to the median nerve at the wrist results in ape hand. a. Following muscles of thenar eminence are affected I. Abductor pollicis, II. Flexor pollicis brevis—superficial head, and III. Opponens pollicis. b. Clinical features I. Paralysis of the muscles of thenar eminence, II. Wasting of thenar eminence resulting in flattening of the thenar eminence, III. The thumb is laterally rotated and adducted, IV. The hand is “ape-like” V. Opposition movement of the thumb is impossible, and VI. The first two lumbricals are paralyzed. It can be recognized clinically when the patient is asked to make a fist slowly. The index and middle fingers tend to lag behind the ring and little fingers. D. Sensory loss: There is loss of sensation over the central part and lateral ½ of the palm and lateral 3½ digits.

4 Upper Limb

Fig. 27.13A: Chimpanzee in the type of ape

Exam-Oriented Anatomy

286

SN-24

Scapular anastomosis

Anastomoses around the body of the scapula (Fig. 27.14). The anastomoses occur in the three fossae and a process. 1. Subscapular fossa A. Posterior circumflex humeral artery, and B. Circumflex scapular artery.

Fig. 27.14: Anastomosis around scapula

Upper Limb

4

2. Supraspinous fossa: Anastomoses between A. Deep branch of transverse cervical artery (branch of subclavian artery) and B. Suprascapular artery, a branch of the thyrocervical trunk (branch of subclavian artery) 3. Infraspinatus fossa: Anastomoses between A. Suprascapular, B. Deep branch of transverse cervical, and C. Circumflex scapular branches. 4. Anastomoses over the acromion process. It is by acromial branches of A. Thoracoacromial artery (2nd part of axillary) B. Suprascapular artery (1st part of subclavian). C. Posterior circumflex humeral artery (3rd part of axillary) Box 27.2 Note that this is an anastomosis between the 1st part of the subclavian artery and the branches of the 2nd and 3rd parts of the axillary artery

28 Cutaneous Nerves, Superficial Veins and Lymphatic Drainage OLA-20 Describe the origin and termination of cephalic vein

1. Origin: Cephalic vein begins at lateral end of dorsal venous arch. 2. Termination: It ends in axillary vein in the deltopectoral groove. LAQ-6

Describe cephalic vein under following heads 1. Origin, 2. Draining areas, 3. Course, 4. Relations, 5. Tributaries, 6. Features, 7. Termination, and 8. Applied anatomy.

Introduction: It is pre-axial superficial vein on the lateral side of upper limb. 1. Origin: It begins at the lateral end of dorsal venous arch in the subcutaneous tissue (Fig. 28.1). 2. Draining areas: It drains lateral side of A. Hand, B. Forearm, C. Arm, and D. Shoulder. 3. Course (Fig. 28.2): It runs on the preaxial border of the upper limb. It forms A. Roof of a. Anatomical snuffbox, and b. Cubital fossa. B. Divides the flexor and extensor muscles of forearm, 287

288

Exam-Oriented Anatomy

Fig. 28.1: Origin and formation of cephalic vein

Upper Limb

4

C. Ascends in front of the elbow superficial to a groove between the brachioradialis and biceps, D. Courses between biceps and brachialis in the arm, E. Runs at the lateral border of pectoralis major, F. Enters the deltopectoral groove, and G. Pierces costocoracoid part of clavipectoral fascia 4. Relations (Fig. 28.2) A. In the beginning, it lies medial to radial nerve and superficial to extensor retinaculum. B. It lies posterior and lateral to styloid process of radius. C. In forearm, it lies superficial to lateral cutaneous nerve of forearm, D. In deltopectoral groove, it is accompanied by deltoid branch of acromiothoracic artery, and E. It runs along infraclavicular nodes. 5. Tributaries A. At the formation: Dorsal digital veins of the thumb. B. During the course: a. Central part of dorsal venous arch, b. Accessory cephalic vein on lateral side of forearm,

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Fig. 28.2: Course, relations and terminations of cephalic vein

c. Median cubital vein, and d. Deep veins. C. Before piercing clavipectoral fascia: Acromial vein, Breast or pectoral vein, Clavicular vein, and Deltoid vein.

ABCD

6. Features

7. Termination A. It terminates into axillary vein at a right angle. B. Homologous vein in lower limb is great saphenous vein.

4 Upper Limb

A. It is the largest tributary of axillary vein, B. It is one of the important structures that pass between pectoralis minor and subclavius, C. In the embryo, a. It crosses in front of the clavicle and b. Ends in external jugular vein. c. It may continue in the postnatal life. d. It may be injured in fracture of clavicle, and D. Most of the radial lymphatics accompany the cephalic vein.

290

Exam-Oriented Anatomy

8. Applied anatomy

Upper Limb

4

 Practical significance  It is largest vein of the upper limb that remains open in distal part.  It serves as a useful guide to the 1st part of axillary artery. This is for following reasons. • The axillary artery is completely concealed by axillary vein. • Follow the cephalic vein and displace axillary vein inferomedially.  It is available for the surgeon to pass a rubber catheter to axillary vein, subclavian veins and to the heart to withdraw samples of blood.  Please note, the catheter passed along with cephalic vein may be impeded by the acute angulation at deltopectoral groove. Hence, cephalic vein is not chosen for cardiac catheterization.  It is frequently used for intravenous therapy. It is easily accessible in anatomical snuffbox. This site has following advantages.  It is selected for indwelling cannula when a lengthy period is anticipated.  The position of the hand, forearm and arm are optimal in this position.  While ligating the branch of radial artery at anatomical snuffbox, the care is taken not to ligate cephalic vein. Cephalic vein lies superficial and artery lies deep to it.  For dialysis, cephalic vein is arterialized. Arterialization of cephalic vein is done as follows: A subcutaneous arteriovenous fistula is created at the wrist by anastomosing the cephalic vein to the radial artery. The wall of the vein is thickened as the pressure in the vein is increased. Such structural change in the wall is called arterialization. This helps repeated puncture in it with wide-bored needle.  During dialysis, the venous and arterial lines of the cannula are introduced in cephalic vein. The impure blood is drawn in the dialysis machine via the venous line and the purified blood is returned to the cephalic vein via the arterial line.  It is interesting to know that during the surgery of the cancer of breast, removable of the clavicular head is spared. It is done to preserve cephalic vein. • In case of blockage of axillary vein, the blood passes through cephalic vein.  In old days, barbers used cephalic vein for letting the blood.  The cephalic vein is preferred in the deltopectoral groove for superior vena cava infusion. OLA-21 Median cubital vein—importance

Importance: The median cubital vein is the vein of choice for intravenous injections, for withdrawing blood from donors, and for cardiac catheterization. 1. The vein is chosen for following reasons. It is A. Fixed by the perforator, and B. Does not slip away during piercing

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Fig. 28.3: Arrangement of median cubital vein

SN-25

Median cubital vein

It is a large communicating vein, which shunts blood from the cephalic vein to the basilic vein. 1. Origin: From cephalic vein, this is present 1" below bend of elbow. It runs obliquely upward and medially. 2. Termination: It ends in basilic vein, 1" above the medial epicondyle. 3. Relations: Superficial to deep A. Skin and fascia, B. Bicipital aponeurosis, and C. Brachial artery. 4. Tributaries: Median antebrachial vein.

 It is commonly used vein for withdrawal of blood for  Investigation, and  Therapeutic purposes (intravenous injection, intravenous fluid, blood).  This vein is fixed by perforator vein. SN-26

Bicipital aponeurosis

Introduction: The medial expansion of biceps tendon is called bicipital aponeurosis. 1. Course and relations A. It descends across the brachial artery and fuses with deep fascia. B. The tendon gives off an extension called the bicipital aponeurosis. It separates median cubital vein from brachial artery.

4 Upper Limb

5. Applied anatomy

292

Exam-Oriented Anatomy

C. It extends to ulna. D. In the cubital fossa, it lies in front of median nerve. 2. Features A. It forms the roof of cubital fossa. B. It protects the brachial artery. C. It separates the median cubital vein from brachial artery. 3. Palpation: It is palpable and conspicuous when the elbow is flexed against resistance.

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29 Arm

OLA-22 Attachments and actions of biceps brachii

1. Attachments (Fig. 29.1) A. Long head: Supraglenoid tubercle of glenoid process of scapula B. Short head: Coracoid process of scapula.

Fig. 29.1: Proximal and distal attachments of biceps brachii muscle

2. Actions A. Strong supinator of superior and inferior radioulnar joints, B. Flexor of elbow joint, and C. Weak flexor of shoulder joint. LAQ-7

Describe musculocutaneous nerve under following heads 1. Root value, 2. Course and relations, 3. Branches, and 4. Applied anatomy. 293

294

Exam-Oriented Anatomy

Introduction: It is a branch of lateral cord of brachial plexus. It is the motor nerve of flexor compartment of arm and sensory nerve to lateral skin of forearm. 1. Root value: C5, C6 and C7. 2. Course and relations: It arises from lateral cord of brachial plexus (Fig. 29.2).

Fig. 29.2.: Relations of musculocutaneous nerve

A. The lateral cord of brachial plexus lies lateral to the 2nd part of axillary artery. B. The nerve lies lateral to 3rd part of axillary artery. It arises at lower border of pectoralis major (Fig. 29.3).

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Fig. 29.3: Musculocutaneous nerve

Arm

295

a. In axilla, it is related to following structures. I. Anteriorly: Pectoralis major. II. Posteriorly: Subscapularis. III. Medially: Axillary artery. IV. Laterally: Coracobrachialis. It leaves axilla, pierces coracobrachialis and enters front of arm. b. In arm: It runs downwards and laterally. I. It passes between biceps and brachialis. II. It pierces deep fascia just below the elbow and continues as lateral cutaneous nerve of forearm. 3. Branches and distribution Table 29.1: Distribution of musculocutaneous nerve Muscular

Cutaneous

Articular

Branch to

• Coracobrachialis • Biceps brachii • Brachialis

• Lateral cutaneous nerve of forearm supplies skin of lateral side of forearm

• Elbow joint • Shoulder joint • Superior radioulnar joint

• Humerus which accompanies nutrient artery

4. Applied anatomy

4 Upper Limb

 About the lesion of musculocutaneous nerve.  It is rare.  It is due to fracture of neck of humerus.  Lesion of the nerve causes:  Loss of strong flexion and supination.  Loss of biceps tendon reflex.  Loss of sensation along the lateral aspect of the forearm.  The pain and anaesthesia may be aggravated by extension of the elbow.  Myotrophy: Marked weakness of flexion of elbow is due to paralysis of bicep brachii and coracobrachialis.  The nerve may be involved in Erb’s paralysis.  The musculocutaneous nerve in a cadaver is identified as  First identify the coracoid process.  The medial muscle arising from the coracoid process is coracobrachialis.  Nerve piercing the coracobrachialis is musculocutaneous nerve.  Biceps reflex: The integrity of musculocutaneous nerve is tested by biceps reflex. It is tested by tapping the tendon of biceps brachii with forearm pronated and is partially extended at elbow. The normal reflex is brief jerk-like flexion of the elbow.  Surgical approach: The musculocutaneous nerve is exposed by opening up the deltopectoral groove. The nerve entering the coracobrachialis is identified as musculocutaneous nerve. Here it lies below the lower border of teres major.

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Box 29.1 The muscles which are supplied by the musculocutaneous nerve can be remembered and recollected by putting the palmar surface of one band on the arm of other side and saying “BBC” and by putting the hand on the lateral surface of forearm and while saying it continues as “lateral cutaneous nerve of forearm”. The first letter “B” in “BBC” stands for “Biceps”. The second letter “B” in “BBC” indicates “Brachialis”. While the letter “C” in “BBC” represents” Coracobrachialis”. Here I would like to draw your attention to the fact that the brachialis has a dual nerve supply. Musculocutaneous nerve supplies medial 2/3rd of brachialis and the lateral 1/3rd is supplied by radial nerve. Hence brachial is called MR brachialis. The letter “M” in “MR” indicates musculocutaneous and “R” stands for radial nerve.

Left hand on the right arm signify that musculocutaneous nerve supplies BBC, i.e. biceps, brachialis, coracobrachialis.

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Left hand on the lateral surface of right forearm signify that musculocutaneous nerve continues as lateral cutaneous nerve of forearm

Box 29.2 Please do watch the video of animation of “BP-15. Musculocutaneous nerve (7.04 minutes)”. OLA-23 Medial pectoral nerve

1. It arises from medial cord, hence it is called medial pectoral nerve. 2. It arises from the anterior primary rami of 8th cervical and 1st thoracic spinal nerve. 3. It supplies pectoralis minor, 4. It pierces sternal fibres of pectoralis major and supply it. 5. It has no cutaneous branch (Fig. 29.4).

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Fig. 29.4: Course and distribution of medial pectoral nerve

OLA-24 Medial cutaneous nerve of forearm

LAQ-8

Fig. 29.5: Medial cutaneous nerve of forearm

Describe brachial artery under following heads 1. Origin, 2. Course and relations, 3. Branches, and 4. Applied anatomy

1. Origin: It is the continuation of axillary artery distal to the lower border of teres major 2. Course and relations A. Peculiarities: It is superficial throughout its course. It is accompanied by a. Veins: Venae commitantes (brachial veins)

4 Upper Limb

Medial cutaneous nerve of forearm 1. It arises from anterior primary rami of C8 and T1. 2. It is the smallest branch of the brachial plexus. 3. It is much bigger than medial cutaneous nerve of the arm. 4. It runs between axillary artery and vein and pierces the deep fascia at the middle of the arm. 5. It supplies skin over the biceps, almost to elbow. 6. It then divides into anterior and posterior branches. 7. It supplies the skin along the ulnar border of the forearm up to the wrist. 8. It is symmetrical with the lateral cutaneous nerve of the forearm. 9. These cutaneous nerves meet along the anterior axillary line.

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Box 29.3 Nerves accompanying brachial artery and its branches I. Brachial artery accompanies median nerve in the upper half of arm. II. Superior ulnar collateral artery, branch of brachial artery, accompanies median nerve in the lower half of the arm, III. Profunda brachii (a branch of brachial artery) accompanies radial nerve, IV. Anterior descending artery (a branch of profunda brachial artery) accompanies radial nerve, and V. Superior ulnar collateral artery (a branch of brachial artery) accompanies ulnar nerve (Fig. 26.6). Artery

Branch of

Accompanying nerve

Site

Brachial

Continuation of axillary artery

Median nerve on the lateral side in anterior compartment of upper part of arm

Upper half of the arm

Profunda brachii Anterior descending artery

Brachial

Radial

Radial groove

Profunda brachii artery

Superior ulnar collateral

Branch of brachial artery

Lower part of anterior compartment of arm Ulnar

Medial side of arm

B. Relations (Fig. 29.6)

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4

a. Anterior I. Skin, II. Superficial fascia, III. Deep fascia, IV. Biceps brachii, and V. Bicipital aponeurosis at the bifurcation. b. Posterior I. Long head of triceps, II. Medial head of III. Coracobrachialis, and IV. Brachialis. c. Lateral: Upper part median nerve. d. Medial I. Medial cutaneous nerve of arm, and II. Lower part of median nerve. C. Termination: The artery divides at the neck of radius into radial and ulnar arteries.

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Fig. 29.6: Relations of brachial artery with ulnar, radial and median nerves in the arm

3. Branches (Fig. 29.7) A. Cutaneous to skin over arm, C. Articular branches to a. Shoulder joint, b. Elbow joint by I. Superior ulnar collateral, and II. Inferior ulnar collateral artery D. Nutrient branch to humerus, E. Anastomotic branch to posterior circumflex humeral artery, and F. Terminal branches: Radial and ulnar arteries. 4. Applied Anatomy

 The brachial artery is ruptured in supracondylar fracture of humerus leading to Volkmann’s ischaemic contracture (Fig. 29.8).

4 Upper Limb

B. Muscular: Muscles of arm (deltoid, biceps, brachialis, coracobrachialis),

300

Exam-Oriented Anatomy

Fig. 29.7: Branches of brachial artery

Upper Limb

4 Fig. 29.8: Supracondylar fracture

 The pulsations of brachial artery are felt or auscultated in front of the elbow medial to tendon of biceps.  Haemorrhage due to brachial artery can be controlled by direct compression of brachial artery. The compression should be in the middle of arm on the tendon of coracobrachialis and medial to humerus.  Blood pressure is recorded by auscultation of the pulsations of brachial artery in cubital fossa.  The blood for blood gas analysis is collected from brachial artery.  The pulsations of brachial artery are felt or auscultated in front of the elbow medial to tendon of biceps.

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OLA-25 Branches of radial nerve in radial groove

1. Branch to medial head of triceps, 2. Branch to lateral head of triceps, and 3. Anconeus.

Fig. 29.9: Branches of radial nerve in radial groove

OLA-26 Branches of radial nerve in axilla

1. Long head of triceps, and 2. Medial head of triceps.

Fig. 29.10: Branches of radial nerve in axilla

OLA-27 Branches of radial nerve in front of lower part of arm

1. Muscular branch A. Brachioradialis, B. Extensor carpi radialis longus, and 2. Proprioceptive branch to brachialis.

Fig. 29.11: Branches of radial nerve in front of lower part of arm

LAQ-9

Describe radial nerve under 1. Root value, 2. Course and relations, 3. Branches, and 4. Applied anatomy.

Upper Limb

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302

Exam-Oriented Anatomy

Introduction: It is the nerve of the extensor compartment of the arm and forearm, supplying the skin over them and on the dorsum of hand. It is the direct continuation of posterior cord of brachial plexus. It is the largest branch of the whole brachial plexus. 1. Root value: It arises from posterior cord of brachial plexus carrying fibres from the ventral roots of spinal nerves C5, C6, C7, C8 and T1. 2. Course and relations (Fig. 29.12): It arises from posterior cord of brachial plexus. The posterior cord lies posterior to the 2nd part of axillary artery and radial nerve lies posterior to 3rd part of axillary artery. It lies medial to axillary nerve. A. Course of radial nerve in lower part of axilla. The nerve passes downwards. It crosses the lower border of posterior axillary wall. It includes crossing of the glistening tendon of latissimus dorsi, and subscapularis. Here it has following relations. a. Anteriorly: Axillary artery and pectoralis major. b. Posteriorly: Subscapularis, teres major and latissimus dorsi. c. Medially: Axillary vein d. Laterally: Coracobrachialis muscle.

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It passes through lower lar space and enters the radial groove along with profunda brachii artery. B. Course of radial nerve in the arm: It enters the arm. It has following relations. It is a. Posterior to brachial artery, b. Medial to humerus, and c. Anterior to long head of triceps. C. Course of radial nerve in radial groove a. The nerve passes obliquely across the back of the humerus. b. The course is from medial to lateral in a shallow groove and between the long and medial heads of triceps. It passes along with profunda brachii artery. c. At lower end of radial groove, it pierces the lateral intermuscular septum and enters into anterior or flexor compartment of the arm. d. In the flexor compartment of the lower arm, it descends in intermuscular slit. D. Course and relations of radial nerve in the intermuscular slit I. In the upper part, it lies between brachialis medially and brachioradialis laterally. II. In the lower part, it lies brachialis medially and extensor carpi radialis longus laterally. E. Course of radial nerve in forearm: At the level of lateral epicondyle, it gives off two terminal branches. The branches are a. Superficial terminal branch, and b. Deep terminal branch. It is called posterior interosseous nerve. a. Superficial terminal branch. It is entirely cutaneous in its distribution. It supplies to the dorsum of hand and fingers. I. Course of superficial terminal branch of radial nerve i. In front of forearm:  It leaves the cubital fossa and enters lateral side of forearm.

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Fig. 29.12: Course, relevant relations of radial nerve Note: The symbol “ ” at the end of nerve signifies the cutaneous branch 

In upper 2/3rd, it is accompanied by radial vessels.



At the junction of upper 2/3rd and lower 1/3rd, it runs laterally and reach posterolateral aspect of forearm.

ii. In hand 

It reaches the wrist and travels in the roof of the anatomical snuffbox

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304

Upper Limb

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Exam-Oriented Anatomy

b. Posterior interosseous branch. I. Course of posterior interosseous nerve: This leaves the cubital fossa by piercing supinator muscle. It enters back of forearm. i. At cubital fossa, it runs downwards on the surface of • Supinator, • Pronator teres, and • Flexor digitorum superficialis. ii. At forearm, it runs on the lateral side of forearm under the cover of brachioradialis. iii. In middle 1/3rd of forearm, it lies lateral to the radial artery. iv. In extensor compartment of lower part of forearm. • It then leaves flexor compartment of forearm, winds around lower end of radius deep to the tendon of brachioradialis. It crosses the structures forming anatomical snuffbox. They are * Abductor pollicis longus, * Extensor pollicis brevis, and * Extensor pollicis longus. Note: On the posterior surface of interosseous membrane, it enlarges into a pseudoganglion. It breaks into 2 or 3 branches which can be rolled on the surface of tautened tendon of extensor pollicis longus. They are distributed to the radial 2/3rd of the dorsum of the hand and proximal parts of the dorsal surfaces of thumb and lateral 2½ or 3½ fingers. 3. Branches of radial nerve (Fig. 29.13) can be described as A. Collateral branches B. Terminal branches A. Collateral branches a. Branches above the radial groove, b. In the radial groove, and c. Below the radial groove. a. Branches above the groove are motor, sensory and articular. I. Motor branches are to the i. Long, and ii. Medial head of triceps. It is called ulnar collateral nerve. II. Sensory branch is posterior cutaneous nerve of arm. III. Articular branch supplies elbow joint. b. Branches in the groove are motor and sensory. I. Motor branches are to i. Lateral, and ii. Medial head of triceps. The branch to medial head of triceps goes deep and supplies anconeus.

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II. There are two sensory branches given in the groove: To the skin of i. Arm, and ii. Forearm. i. The cutaneous branch given in the arm is called lower lateral cutaneous nerve of arm. It pierces the lateral head of triceps to supply the skin over the lateral surface of arm up to elbow. ii. The cutaneous nerve of forearm is called posterior cutaneous nerve of forearm. It runs straight behind the elbow to supply a strip of skin over the extensor surface of the forearm up to the wrist. c. The branches given below the groove are I. Motor to i. Brachioradialis and ii. Extensor carpi radialis longus, II. Proprioceptive to lateral part of brachialis. B. Terminal branches: The radial nerve divides at the level of lateral epicondyle into superficial and deep terminal branches (posterior interosseous nerve). a. Superficial branch is the continuation of the main nerve. It is purely cutaneous and is distributed to the skin of I. Lateral 1/2 of the dorsum of hand II. Proximal parts of dorsal surface of the i. Thumb, ii. Index fingers, and iii. Lateral ½ of middle finger. b. Deep branch is motor and is called posterior interosseous nerve. It supplies I. Muscles in cubital fossa i. Extensor carpi radialis brevis, and ii. Supinator II. Muscles in the extensor compartment (7 muscles). They are conveniently divided in two groups for easy recollection. i. 1st group includes • Extensor muscles reaching wrist, index finger, digits and little finger. They are – Extensor carpi ulnaris, – Extensor indices, – Extensor digitorum, and – Extensor digiti minimi. ii. 2nd group • The muscles forming anatomical snuffbox. They are – Abductor pollicis longus, – Extensor pollicis brevis, and – Extensor pollicis longus

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Upper Limb

4 Fig. 29.13: Branches of radial nerve in the arm and forearm Note: 1. The symbol “

” at the end of nerve signifies the branch

2. The symbol “ ” at the end of nerve signifies the cutaneous branch

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Box 29.4 Note i. The radial nerve is also sensory to the wrist and carpal joints. ii. Dorsum of hand proximal to 1st web space is an autonomous area for radial nerve. Autonomous sensory area is part of a dermatome that has no overlap from adjacent nerves. 4. Applied anatomy of radial nerve

 The radial nerve is very commonly damaged in the region of radial groove. The common causes are: – Saturday night palsy (Fig. 29.14A): When an intoxicated person falls asleep with his arm hanging over the edge of a chair. The prolonged pressure causes damage to the radial nerve as it is in the radial groove. As a result, in the morning, he finds that he is suffering from wrist drop.  It is characterized by flexion of wrist, and flexion of metacarpophalangeal joint.  The interphalangeal joints are not affected in wrist drop. They remain straight. This is because of action of interossei and lumbricals.  Testing: This can be detected by testing elbow extension.  It is purely a transient condition. – An interesting term, bridegroom’s paralysis, has been coined for the compression of radial nerve in the radial grove. It results when the head of the spouse is lying on the arm of the other spouse. – The other causes of radial nerve injury include crutch paralysis and fracture of the shaft of humerus (Fig. 29.14B). – All these conditions result in weakness and loss of power of extension of wrist joint. This is called wrist drop (Fig. 29.14C).

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Fig. 29.14A: Saturday night palsy

Fig. 29.14B: Crutch palsy

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Fig. 29.14C: Wrist drop

  

 

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– There is minimum sensory loss which is confined to 1st dorsal interosseous. This is because there is an overlap of the nerve supply by median and ulnar nerves. In addition to wrist drop, there is sensory loss over a narrow strip on the back of forearm and lateral side of dorsum of hand. Injury to the superficial branch results in small sensory loss over the root of the thumb. The integrity of the radial nerve can be confirmed by testing the sensations over the dorsum of the hand proximal to 1st web space. Surgical approach – Exposure of radial nerve. – First, the radial nerve may be exposed from the back by developing an interval between the long and lateral head of triceps. Here the nerve crosses the upper part of the medial head. The superficial and deep branches of radial nerve can be exposed by retracting the brachioradialis and extensor carpi radialis longus. The deep branch is exposed by incising deep part of supinator muscle.

Box 29.5 Distribution of radial nerve. The key word for the muscles supplied by radial nerve is BEST. The letter B represents Brachialis. The letter E stands for Extensors of forearm. The letter S denotes Supinator. The letter T represents Triceps. SN-27

Applied anatomy of radial nerve

Applied anatomy : Injury to radial nerve at different levels (Table 29.2).

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Table 29.2: Injury to radial nerve at various sites and the effects of sensory and motor nerves Site

Cause

Effect Motor

Sensory

A. • Axilla

• Saturday night palsy • Extensor muscles of • Crutch palsy arm, forearm and wrist are paralysed

B. • Middle of arm

• Fracture of shaft of humerus • Injection in radial groove

C. • Proximal part of forearm

• Fracture of proximal • Paralysis of extensors • Loss of sensations of 1/3rd of radius of wrist and hand radial side of dorsum of hand

D. • Wrist joint • Lesion of superficial radial nerve at wrist

• Paralysis of extensors • Loss of sensations of of forearm and wrist dorsum of hand

• No muscles are paralysed

• Loss of sensations of radial side of dorsum of hand

Wrist drop

Introduction: It is loss of extension of wrist due to paralysis of extensor muscles of the wrist joint. 1. Nerve involved: It is produced by the lesion of radial nerve and/or posterior interosseous branch of radial nerve. 2. Causes of the injury A. In the axilla a. Saturday night palsy, and b. Crutch palsy. B. In the middle of the arm a. Fracture of middle 1/3rd of the shaft of humerus, and b. Injection in radial groove. . C. In the proximal part of forearm: Fracture of proximal 1/3rd of radius 3. Muscles paralysed A. Extensor carpi radialis brevis B. Supinator, C. Muscles forming anatomical snuffbox. a. Abductor pollicis longus b. Extensor pollicis brevis c. Extensor pollicis longus D. Other muscles a. Extensor indices, b. Extensor digitorum,

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SN-28

• Loss of sensations of posterior surface of arm, and dorsum of hand

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c. Extensor digiti minimi, and d. Extensor carpi ulnaris. 4. Clinical manifestations A. Motor: The patient is unable to extend the wrist and results into wrist drop. B. Sensory: A variable small area of anaesthesia is present over the dorsal surface of the hand and dorsal surface of the roots of the lateral 3½ fingers (Fig. 29.14C). SN-29

Profunda brachii artery

1. Origin: It is the largest and deep (profunda—deep) branch of the brachial artery. 2. Course and relations (Fig. 29.15): It accompanies the radial nerve in the lower lar space and radial groove. It pierces the lateral intramuscular septum and divides into branches.

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4 Fig. 29.15: Course and relations of profunda brachii artery

3. Branches (Fig. 29.16) A. Deltoid branch: It ascends between the long and lateral head of triceps and anastomoses with the descending branch of posterior circumflex humeral artery. B. Nutrient artery to the humerus. C. The radial collateral artery is one of the terminal branches and represents the continuation of the profunda artery. It ends by anastomosing with the radial recurrent artery. D. The middle collateral artery is the larger terminal branch. It ends by anastomosing with the interosseous recurrent artery.

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Fig. 29.16: Branches of profunda brachii artery

OLA-28 What structures pass between medial and lateral head of triceps?

1. Radial nerve, 2. Profunda brachial artery, and 3. Profunda brachial vein.

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Fig. 29.17: Structures present between medial and lateral head of triceps

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OLA-29 Boundaries of cubital fossa

1. Medially by lateral border of pronator teres, and 2. Laterally by medial border of brachioradialis. OLA-30 Contents of cubital fossa

1. Radial nerve and its terminal branches A. Superficial branch, and B. Posterior interosseous nerve. 2. Bicipital aponeurosis 3. Brachial artery and its terminal branches A. Larger ulnar artery a. Anterior ulnar recurrent, b. Posterior ulnar recurrent, c. Common interosseous, I. Anterior interosseous, and II. Posterior interosseous. d. Smaller radial artery and its branch—radial recurrent

Upper Limb

4 Fig. 29.18: Contents of cubital fossa

4. Brachial vein and its tributaries 5. Median nerve and its branches A. Muscular artery a. Flexor carpi radialis, b. Palmaris longus, c. Flexor digitorum superficialis, and d. Flexor digitorum profundus (lateral half).

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OLA-31 Applied anatomy of cubital fossa

1. Median cubital vein is the most fixed vein. Hence it is used for withdrawal of blood for investigation purposes and giving intravenous fluid. 2. The brachial artery is auscultated for recording blood pressure. 3. The brachial artery is selected for withdrawal arterial blood for blood gas analysis.

Fig. 29.19: Site of palpation of brachial artery in cubital fossa

4. The cubital vein is used for the introduction of cardiac catheter to secure blood samples from the great vessels and chambers of heart. 5. The supracondylar fracture of humerus results into rupture of brachial artery. It results into Volkmann’s ischaemic contracture LAQ-10 Describe cubital fossa under following heads 1. Boundaries, 2. Contents, and 3. Applied anatomy.

lar fossa present in front of elbow joint.

1. Boundaries A. Medial boundary is formed by lateral border of pronator teres. B. Lateral boundary is formed by medial border of brachioradialis. C. Roof (Fig. 29.20): It is formed by a. Skin and superficial fascia containing I. Medial cutaneous nerve of forearm, II. Lateral cutaneous nerve of forearm, III. Medial cubital vein which is joined by i. Cephalic vein, and ii. Basilic vein. b. Deep fascia and bicipital aponeurosis.

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Introduction: It is a shallow

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Fig. 29.20: Roof of the cubital fossa

D. Floor (Fig. 29.21) a. Upper part: Formed by lower part of brachialis. b. Lower part: Formed by upper part of supinator. E. Base by imaginary line joining the medial and lateral epicondyle. F. Apex is formed by meeting point of medial border of brachioradialis and lateral border of pronator teres.

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4 Fig. 29.21: Floor of right cubital fossa

2. Contents A. Main contents: From lateral to medial are Ravina Tandon ke Baton Me R T B M

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Radial nerve divides into Tendon of biceps Brachial artery Median nerve. B. Minor contents are a. Deep branch of radial nerve: It continues as posterior interosseous branch. It gives b. Muscular branches to I. Supinator II. Extensor carpi radialis brevis c. Terminal divisions of branchial artery, namely I. Radial artery, and II. Ulnar artery d. Musculocutaneous nerve. It lies at the lateral margin of biceps tendon. Here it continues as lateral cutaneous nerve of forearm. e. Muscular branches of median nerve in the cubital fossa are I. Pronator teres, II. Palmaris longus, III. Flexor carpi radialis, IV. Flexor digitorum superficialis (Fig. 29.22)

f. Anterior interosseous nerve, branch of median nerve. g. Small isolated lymph nodes sometimes occur along radial, ulnar and interosseous arteries. 3. Applied anatomy

 Median cubital vein is the most fixed vein. Hence it is used for withdrawal of blood for investigation purposes and giving intravenous fluid.  Brachial artery is auscultated for recording blood pressure.  Brachial artery is selected for withdrawal arterial blood for blood gas analysis.  The median cubital vein is used for the introduction of cardiac catheter to secure blood samples from the great vessels and chambers of heart. The supracondylar fracture of humerus results into rupture of brachial artery and ends into condition called Volkmann’s ischaemic contracture.

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Fig. 29.22: Relations of structures in the cubital fossa

30 Forearm and Hand

OLA-32 Branches of radial artery in forearm

Branches in (Fig. 30.1) 1. Forearm A. Radial recurrent artery B. Muscular branches 2. Hand A. Branches of deep palmar arch a. Branch to superficial palmar branch, b. Princeps pollicis artery, and c. Radialis indicis artery. d. Palmar metacarpal branch B. Dorsum of hand: Dorsal carpal branch LAQ-11 Describe ulnar artery under following heads 1. Origin, 2. Course and relations, 3. Branches, and 4. Applied anatomy.

Introduction: It is the artery of medial side of forearm. 1. Origin: This larger terminal branch of brachial artery arises 1 cm below the bend of elbow. 2. Course and relations A. Peculiarities: It is accompanied by a. Venae commitantes, and b. Ulnar nerve in the distal 2/3rd of forearm. B. Extent: It extends from elbow to wrist joint. 316

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Fig. 30.1: Branches of right radial artery

C. Termination: Ulnar artery forms superficial palmar arch in the hand. D. Course (Fig. 30.2): It passes downward, medially. a. It leaves cubital fossa deep to ulnar head of pronator teres. b. It lies between two nerves, laterally the median and medially the ulnar nerve. E. Relations (Fig. 30.2) I. Upper half i. Muscles 

Pronator teres,



Flexor carpi radialis,



Flexor digitorum superficialis, and



Palmaris longus

ii. Nerve: Median nerve II. Lower half i. Skin ii. Superficial fascia b. Posterior

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a. Anterior (Table 30.1)

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Table 30.1: Anterior relations of ulnar artery in the upper and lower ½ of the forearm Upper half

Lower half

• • • • •

• • • •

Pronator teres Flexor carpi radialis Palmaris longus Flexor digitorum superficialis Flexor carpi ulnaris

Skin Superficial fascia Deep fascia Palmar cutaneous branch of ulnar nerve

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4 Fig. 30.2: Course and relations of right ulnar artery

I. Flexor digitorum profundus, and II. Pronator quadratus. c. Lateral: Flexor digitorum superficialis. d. Medial: Flexor carpi ulnaris and ulnar nerve. 1. Branches (Fig. 3.3) A. Muscular branch to all the superficial group of muscles on medial side of forearm and hand

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B. Cutaneous C. Articular branch to a. Elbow, and b. Wrist joint. D. Branches to nerves a. Ulnar, and b. Median. E. Nutrient arteries to a. Radius, and b. Ulna. F. Communicating branches to a. Anterior, b. Posterior carpal arch, and c. Superficial palmar arch. G. Terminates as a. Superficial palmar arch, and b. Branch to synovial sheath.

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Fig. 30.3: Branches of ulnar artery

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2. Applied anatomy : It is felt lateral to flexor carpi ulnaris and above the pisiform

bone. Note: For easy recalling remember the digit ‘2’  One of 2 terminal branches of brachial artery.  Extends between 2 joints, namely elbow and wrist joint, i.e. neck (of radius) to head (of ulna).  Passes between 2 nerves:  Median, and  Ulnar.  Relations with 2 groups of muscles  Superficial, and  Deep.  Lies on 2 muscles  Brachialis, and  Flexor digitorum profundus.  Branches: Mnemonic for branches of ulnar artery is. “BRANCHIS” Branches to 2 Bones: Radius, and ulna. 2 Recurrent: Anterior ulnar recurrent, and posterior ulnar recurrent. 2 Articular to: Elbow joint, and wrist joint. 2 Nerves: Ulnar, and median. 2 Carpal bones: Anterior, and posterior carpal. 2 Branches to Hand: Superficial palmar arch and deep palmar arch. 2 Interosseous membrane: Anterior interosseous and posterior interosseous artery 2 group of muScles: Superficial, and deep.

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OLA-33 Name the boundaries and contents of anatomical snuffbox

Boundaries and contents: Boundaries, floor and contents are formed by “3” structures each. 1. 3 structures form boundaries, 3 structures form floor and 3 structures form the contents. A. Laterally: Tendon of a. Abductor pollicis longus, and b. Extensor pollicis brevis. B. Medially: Extensor pollicis longus. 2. Floor: From proximal to distal 3 bones A. Scaphoid,

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B. Trapezium, and C. Base of 1st metacarpal bone. 3. Contents are 3: From superficial to deep A. Cephalic vein (over the roof), B. Superficial branch of radial nerve, and C. Radial artery. SN-30

Anatomical snuffbox

Introduction: It is a depressed lar area present on the lateral side of wrist and become prominent when thumb is fully extended. 1. Boundaries and contents: Boundaries, floor and contents are formed by “3” structures each (Fig. 30.4). 3 structures form boundaries, 3 structures form floor and 3 structures form the contents. “3” A. Laterally: Tendon of abductor pollicis longus and tendon of extensor pollicis brevis. B. Medially: Extensor pollicis longus. 2. Floor: From proximal to distal 3 bones A. Scaphoid, B. Trapezium, and C. Base of 1st metacarpal bone.

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Fig. 30.4: Boundaries, floor and contents of anatomical snuffbox

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3. Contents: From superficial to deep A. Cephalic vein (over the roof), B. Superficial branch of radial nerve, and C. Radial artery. 4. Applied anatomy

 Person having fracture of scaphoid complains pain in the wrist. There is no impairment of function OLA-34 What are the attachments of flexor retinaculum?

1. Proximally (Fig. 30.5A) and A. Laterally to tubercle of the scaphoid, and B. Medially to hook of the pisiform. 2. Distally (Fig. 30.5B) and A. Laterally to crest of the trapezium, and B. Medially to hook of hamate. 3. On either side, the retinaculum has a slip: Lateral deep slip is attached to the medial lip of the groove on the trapezium. The medial superficial slip (volar carpal ligament) is attached to the pisiform bone.

Fig. 30.5A: Carpal bones forming proximal row of carpal tunnel

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Fig. 30.5B: Carpal bones forming distal row of carpal tunnel

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323

Flexor retinaculum

Introduction: It is a strong fibrous band of deep fascia connecting proximal and distal carpal bones of medial and lateral side (Fig. 30.6). 1. Gross anatomy Table 30.2: Attachments of flexor retinaculum Particulars

Proximal

Distal

• Attachment • Medially • Laterally

• To pisiform bone. • It also gives attachment to extensor retinaculum. • To tubercle of scaphoid

• To hook of hamate. • To medial lip of groove of trapezium

• Termination

• Antebrachial fascia • Fascia covering flexor digitorum superficialis

• Palmar aponeurosis • Palmar fascia

2. Relations Table 30.3: Relations of the flexor retinaculum Particulars

Superficial

Deep

• Tendon

• Palmaris longus

• • • •

• Arteries

• Ulnar artery • Superficial palmar branch of radial artery

—

• Nerve

• Ulnar nerve • Palmar cutaneous branch of ulnar nerve • Palmar cutaneous branch of median.

• Median nerve

• Synovial sheath

—

• For flexor tendons • Radial bursa • Ulnar bursa (Fig. 30.6)

3. Importance A. It gives origin to thenar and hypothenar muscles. B. The tendon of palmaris longus is fused in the midline. C. It keeps all the flexor tendons in position. D. It converts bony gutter into tunnel. E. It prevents bowstringing of muscles during, flexion thereby leading to effective contraction.

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• Bursae

FDS—Flexor digitorum superficialis—4 FDP—Flexor digitorum profundus—4 FPL—Flexor pollicis longus—1 FCR—Flexor carpi radialis

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Fig. 30.6A: Structures deep to flexor retinaculum

Fig. 30.6B: Structures superficial to flexor retinaculum

SN-32

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4

Extensor retinaculum

1. Definition: The deep fascia on the back of the wrist is thickened to form the extensor retinaculum. It holds the extensor tendons in place. It is an oblique band, directed downwards and medially. It is about 2 cm broad vertically. 2. Attachments (Fig. 30.7) A. Laterally: Lower part of the anterior border of the radius. B. Medially a. Styloid process of the ulna, b. Triquetral, and Fig. 30.7: Attachments of extensor retinaculum c. Pisiform. 3. Compartments: The retinaculum sends septa and makes various compartments. They are attached to the longitudinal ridges on the posterior surface of the lower end of radius. In this way, 6 osseofascial compartments are formed on the back of

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the wrist. The structures passing through each compartment, from lateral to the medial side, are A. 1st compartment a. Abductor pollicis longus b. Extensor pollicis brevis B. 2nd compartment a. Extensor carpi radialis longus b. Extensor carpi radialis brevis, C. 3rd compartment: Extensor pollicis longus, D. 4th compartment a. Extensor digitorum, b. Extensor indicis, c. Posterior interosseous nerve, d. Anterior interosseous artery, E. 5th compartment: Extensor digiti minimi, and F. 6th compartment: Extensor carpi ulnaris. OLA-35 Name the muscles supplied by median nerve in hand

LOAF 1st and 2nd Lumbricals, Opponens pollicis, Abductor pollicis brevis, and Flexor pollicis brevis—superficial head. LAQ-12 Describe median nerve under following heads 2. Branches, and 3. Applied anatomy.

1. Root value: Median nerve has lateral and medial roots. Lateral root is the continuation of the lateral cord of brachial plexus and has C5, C6 and C7 fibres. The medial root is derived from the medial cord and has C8 and T1 fibres. A. Course and relations (Fig. 30.8): The lateral and medial roots clasp 2nd part of axillary artery and lie on the respective sides. B. In axilla a. The medial root crosses the 3rd part of axillary artery from front. It joins the lateral root, and the nerve is formed on lateral side at the lower border of axilla.

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1. Root value,

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Fig. 30.8: Course and relevant relations of median nerve Note: 1. The symbol “ ” at the end of nerve signifies the cutaneous branch

b. It enters the arm. It then passes vertically down lateral to brachial artery.

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c. In the middle of arm, it crosses brachial artery from front. d. It remains on medial side of brachial artery in lower part of arm. e. It courses between biceps brachii and brachialis. f. In cubital fossa, it crosses ulnar artery from medial to lateral. C. In the cubital fossa (Fig. 30.9) a. It is most medial important structure of cubital fossa. b. It passes between two heads of pronator teres. c. The relations in lower part of cubital fossa from superficial to deep are I. Superficial head of pronator teres II. Median nerve III. Deep head of pronator teres IV. Ulnar artery.

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Fig. 30.9: Distribution of median nerve in hand

4 Upper Limb

D. In forearm a. It runs distally in the midline of forearm. b. It is closely attached to the deep surface of the flexor digitorum superficialis muscle. c. It passes between superficial and deep muscles of forearm. d. It is accompanied by median artery (branch of anterior interosseous artery). E. In wrist a. Above the wrist, the nerve comes close to the surface between the tendons of I. Flexor carpi radialis, and II. Flexor digitorum superficialis. b. It lies deep and partly lateral to the tendon of palmaris longus. c. It passes deep to flexor retinaculum, surrounded by 10 tendons. These are I. Four superficial flexor tendons of digits, II. Four deep flexor tendons of digits, III. A long deep tendon of thumb, and IV. A tendon of radial side of wrist. d. After giving recurrent branch, it divides into I. Lateral, and II. Medial branch. III. The lateral branch subdivides into three palmar digital branches, which supply the i. Skin of both sides of thumb, and ii. Radial side of index finger.

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 The branch to index finger provides a muscular branch to 1st lumbrical. IV. The medial branch subdivides into two common palmar digital nerves. Lateral common digital nerve gives a branch to 2nd lumbrical. F. Median nerve gives anterior interosseous nerve which accompanies anterior interosseous artery and supplies a. Flexor pollicis longus, b. Pronator quadratus, and c. Lateral 1/2 of flexor digitorum profundus.

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2. Branches (Fig. 30.10) They are grouped as branches in the a. Arm, b. Cubital fossa, c. Forearm, and d. Hand. e. In the arm, it gives I. Sympathetic filaments to the brachial artery, and a twig to the II. Elbow joint. f. In cubital fossa, the median nerve gives a branch to pronator teres. After emerging from the pronator teres, it supplies I. Flexor carpi radialis, II. Palmaris longus, and III. Flexor digitorum superficialis g. In the forearm, it gives off I. Anterior interosseous nerve II. Palmar cutaneous branch III. Anterior interosseous nerve: It descends on the interosseous membrane up to the wrist. The nerve ends in the anterior part of capsule of the wrist and carpal joints. It is sensory branch to these joints. Before the nerve ends, it supplies i. Radial ½ of flexor digitorum profundus, ii. Flexor pollicis longus, and iii. Pronator quadratus. IV. Palmar cutaneous branch: It arises about 5 cm proximal to the wrist, pierces the deep fascia just superficial to the flexor retinaculum. It supplies the skin of the thenar muscles. h. Hand: It divides into lateral and medial. I. Lateral, and II. Medial branches

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Fig. 30.10: Branches of median nerve Note:

III. Lateral branch is muscular. It is short and stout. It recurves around distal border of the flexor retinaculum to supply the three thenar muscles, namely i. Abductor pollicis, ii. Superficial head of flexor pollicis brevis, and iii. Opponens pollicis. IV. Medial branches are cutaneous. They are three in number. They are palmar digital branches. i. The 1st two supply the skin of  Sides of the thumb,  Its web, and Table 30.4  Distal part of dorsal surface.

4 Upper Limb

1. The symbol “ ” at the end of nerve signifies the articular branch 2. The symbol “ ” at the end of nerve signifies the cutaneous branch

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Table 30.4: Various positions of hand, muscles involved and tests carried for muscle testing Position of hand

Muscles involved

Testing of nerve

• Unable to bend terminal phalanx of thumb • Forearm is kept in supine position • Hand is adducted • Signs of benediction

• Flexor pollicis longus

• Hold the proximal phalanx of thumb and ask to flex the terminal phalanx. • Pronation of the forearm.

• Pronator teres and pronator quadratus • Flexor carpi radialis • Index and middle fingers cannot be flexed and thumb cannot be opposed • Ape thumb deformity • Flexor pollicis brevis • Opponens pollicis • Abductor pollicis brevis

• Unable to hold a paper between thumb and index finger.

ii. The 3rd supplies the skin of  Radial side of index finger, and  1st lumbrical muscle. 3. Applied anatomy

 Injury above the elbow joint: The cause of injury is mainly by supracondylar fracture of the humerus.  Injury at the middle of forearm: Flexor digitorum superficialis is paralysed leading to condition called “Pointing index finger”.  At wrist: The main cause is compression of median nerve in the carpal tunnel. Table 30.5: Clinical manifestations of compression of median nerve in the carpal tunnel

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Position of hand

Muscles affected

Testing of nerve

• Ape thumb deformity: • Thumb is adducted and laterally rotated.

• Flexor pollicis brevis • Opponens pollicis • Abductor pollicis brevis

• Counting of fingers • Index and middle fingers are lagging in flexing the index finger while making a fist

• It is a nerve in humans and other animals in the upper limb. • It supplies the opponens pollicis muscle which brings the opposition of thumb. • The median nerve is called peripheral eye because it provides sensory innervations to lateral 3½ digits which are used to see the thinness and texture of cloth. It is better appreciated by hand through palpation than with the vision. • It is also called eye of the hand because the loss of sensations over the thumb and index finger renders the hand virtually useless in buttoning a coat or a shirt. Fig. 30.11: Hand of • To be concise and precise about median nerve, we can say. benediction

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Box 30.1

OLA-36 Name the superficial flexors of forearm and their nerve supply.

Superficial flexors of forearm 1. Pronator teres, 2. Flexor carpi radialis, 3. Palmaris longus, 4. Flexor digitorum superficialis, and 5. Flexor carpi ulnaris. 6. Nerve supply: All superficial flexors are supplied by median nerve except flexor carpi ulnaris which is supplied by ulnar nerve.

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It is called ‘median nerve’ because it passes down the middle of the front of the arm. It is one of the 5 main nerves of the upper limb originating from the brachial plexus. It supplies most of the flexor muscles of the forearm and only three muscles, and two lumbricals in the hand. It is cutaneous to the flexor surfaces, and nails of 3½ digits and a corresponding area of the palm. It is worth noting that right from its formation, the median nerve enjoys in dancing from medial to lateral and vice versa. It literally forgets to give branches in arm except sympathetic branch to artery and articular branch to elbow joint. I emphasise this piece of information because it is very important to answer the MCQs based on relations of artery and nerve in arm and cubital fossa. In forearm, it slips between superficial and deep groups of flexor muscles of forearm and sleeps on the mattress formed by flexor digitorum profundus and blanketed by flexor digitorum superficialis—the muscles of forearm. It is interesting to note that here it is accompanied by its fellow brother, i.e. median artery, a branch of anterior interosseous artery. Please remember, It is the nutrient artery to the median nerve. Anterior interosseous nerve is the nerve of the deep flexor muscles of forearm. Apart from above muscles, it supplies interosseous membrane and periosteum of radius and ulna. Friends, it is important to note here some of the additional features of the common digital nerve. The lateral common digital nerve supplies 2nd lumbrical. The medial branch of common digital nerve gives a communicating branch to common digital branch of ulnar nerve. The pulp pads of index finger and middle finger are exclusively supplied by median nerve. Such areas are autonomous sensory areas. Lastly the median nerve does give articular branches to the wrist joint—metacarpophalangeal and interphalangeal branches.

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OLA-37 Branches of ulnar nerve in forearm

1. 2. 3. 1.

Articular, Muscular, and Cutaneous. Articular branch to the elbow joint. It is given as the nerve lies on medial collateral ligament. 2. Muscular branches to A. Medial half of flexor digitorum profundus, and B. Flexor carpi ulnaris. 3. Cutaneous branches are palmar cutaneous and dorsal cutaneous. A. Palmar cutaneous branch. a. It pierces the deep fascia above the flexor retinaculum. b. It supplies the skin over the hypothenar muscles. B. Dorsal cutaneous branch: a. It winds around the lower end of ulna. b. It is distributed to the skin of dorsal surface of 1½ finger except the skin over the I. Distal phalanx of the little finger, and the II. Middle and distal phalanges of ring finger. III. It is important to note that pulp of little finger is an autonomous area for ulnar nerve. Autonomous sensory area is that part of a dermatome that has no overlap from adjacent nerves. OLA-38 Name the muscles inserted in the extensor expansion of index finger Table 30.6: Muscles inserted in the extensor expansion of index finger

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Particulars

Index finger

• Extensor digitorum

•2

• Lumbrical

• First

• Palmar interossei

• Second

• Another extensor

• Extensor digitorum indicis

• Dorsal interossei

• First

OLA-39 Enumerate the muscles pass through the carpal tunnel.

Muscles passing from superficial to deep are 1. Four tendons of flexor digitorum superficialis, 2. Flexor carpi radialis, 3. Four tendons of flexor digitorum profundus, and 4. Flexor pollicis longus.

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Carpal tunnel

Introduction: It is a fibro-osseous tunnel formed by concave palmar surfaces of carpal bones. It is situated in the lower part of anterior surface of forearm. 1. Location: It is located near the wrist joint. 2. Formation A. Pillars Table 30.7: Bones forming the pillars of carpal tunnel Particulars

Laterally

Medially

• Proximal row

• Scaphoid

• Pisiform

• Distal row

• Trapezium

• Hamate

B. Anterior: Flexor retinaculum. C. Posterior: Palmar surfaces of carpal bones. 3. Relations A. Anteriorly a. Skin, b. Palmaris longus tendon, c. Palmar cutaneous branch of ulnar nerve, d. Palmar cutaneous branch of median nerve, e. Superficial palmar branch of radial artery, f. Ulnar nerve, and g. Ulnar vessels. B. Posteriorly palmar surfaces of carpal bone 4. Contents (Fig. 30.12) (From superficial to deep): B. Flexor carpi radialis, C. Flexor digitorum profundus, D. Flexor pollicis longus, E. Median nerve, and F. Radial and ulnar bursa. 5. Applied anatomy

Carpal tunnel syndrome: Compression of median nerve in the carpal tunnel gives rise to loss of sensations and weakness of the muscles of the thenar eminence, which constitute the carpal tunnel syndrome.  Etiology: Following are the causes of carpal tunnel syndrome.

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A. Flexor digitorum superficialis,

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Fig. 30.12: Transverse section of the carpal tunnel showing boundaries and contents

Box 30.2 • MEDIAN TRAP – Myxedema – Edema premenstrual – Diabetes mellitus – Acromegaly – Neoplasia – Trauma – Rheumatoid arthritis – Amyloidosis – Pregnancy

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 Gender variation: Carpal tunnel syndrome is common in females .  Age group: Occurs between 40 and 70 years.  Clinical features: It presents as  Intermittent attacks of pain, which are more in the night. It is referred to proximal part of forearm. It may be relieved by dorsiflexion.  Wasting of thenar muscles, namely • Flexor pollicis brevis, • Opponens pollicis, and • Abductor pollicis brevis.  Treatment  Pain is relieved by splinting of the wrist in slight dorsiflexion.  The division of flexor retinaculum is required in severe cases. OLA-40 Cutaneous supply of palm of hand

Palmar surface 1. Lateral 3½ fingers—median nerve. 2. Medial 1½ fingers—ulnar nerve.

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OLA-41 Cutaneous supply of dorsum of hand

Dorsal surface 1. Lateral 2½ fingers—median nerve. 2. Medial 2½ fingers—radial nerve. SN-34

Palmar aponeurosis

It is a flattened tendon of palmaris longus present in the hand. 1. Features A. Shape: lar B. Apex: Blends with the flexor retinaculum. C. Base: It is directed distally and divides into 4 slips opposite the head of metacarpals of the medial four fingers. Each slip divides into two parts which provides the passage for digital vessels, nerves and tendons of lumbricals. The palm is divided into compartments by the slips arising from lateral and medial margins of palmar aponeurosis. 2. Morphology: Phylogenetically it represents degenerated tendon of palmaris longus. It is homologous to plantar aponeurosis. 3. Functions A. It improves the grip of the hand by fixing the skin. B. It protects the vessels and nerves of palmar surface of hand. 4. Applied anatomy

 Dupuytren’s contracture: It is an inflammation of ulnar side of palmar aponeurosis. There is thickening and contracture of the palmar aponeurosis. Dupuytren’s contracture

Introduction: It is an inflammation of ulnar side of palmar aponeurosis. There is thickening and contracture of the palmar aponeurosis (Fig. 30.13). 1. Cause: It is due to fibrosis and shortening of the palmar aponeurosis 2. Features A. Usually the left hand is involved. B. It is more severe towards the ulnar side. C. There is progressive flexion of the 4th and 5th digit. D. There is an involvement of proximal and middle phalanx because of insertion of palmar aponeurosis. E. A high correlation exists between Dupuytren’s contracture and coronary artery disease. It is possibly due to result of vasospasm of the arteries innervated by 1st thoracic spinal nerve.

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Fig. 30.13: Dupuytren’s contracture

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Dorsal digital expansion

Introduction: It is a small aponeurosis formed by each extensor tendon which covers the dorsum of proximal phalanx and the sides of its base (Fig. 30.14). 1. Shape: It is lar, base directs proximally and apex directs distally. 2. Formation: It is mainly formed by extensor digitorum tendon and it is contributed by interossei and lumbrical muscles. In addition to above tendon A. In little finger, it is formed by extensor digiti minimi, and B. In index finger, by extensor indicis.

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4 Fig. 30.14: Dorsal digital expansion

3. Features A. Base of dorsal digital expansion a. It covers the dorsal and collateral aspects of metacarpophalangeal joint. b. It gives attachment to extensor tendon at the centre of base of digital expansion. c. It forms hood over head of metacarpal. d. It is movable distally and proximally with the flexion, extension at metacarpophalangeal joint. e. Each basal angle is attached to deep transverse metacarpal ligament.

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B. Margins: The lateral margin is thickened by insertion of tendon of lumbricals and interossei muscles. The medial margin is thickened by the attachments of interossei only. C. Wing tendons are of two types a. Proximal wings: Formed by dorsal and palmar interossei. b. Distal wings: Formed by lumbricals. D. Apex of expansion: At the distal end of proximal phalanx, the apex of the expansion is divided into three bands. They are: a. One central, and b. Two collaterals. The central band is inserted to the base of middle phalanx. The two collateral bands unite and finally are inserted into the dorsal aspect of the base of distal phalanx. 4. Actions A. It keeps the extensor tendons in the midline. B. It is the only extensor of metacarpophalangeal joints (besides the extensor indices and the extensor digiti minimi) for the medial 4 fingers. C. The collateral bands extend the proximal and distal interphalangeal joint through the dorsal digital expansion. OLA-42 Enumerate the muscles inserted in the extensor expansion of middle finger Table 30.8: Muscles inserted in the extensor expansion of middle finger Particulars

Middle finger

• Slip of extensor digitorum

• 1

• Lumbrical

• Second

• Dorsal interossei

• Second and third

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Fig. 30.15: Extensor expansion of middle finger

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LAQ-13 Describe interossei under following heads, 1. Insertion, 2. Axis, 3. Strength, 4. Relation, 5. Action, 6. Nerve supply, and 7. Testing.

(Inter—in between, ossei—bone) Introduction: These are the small muscles of the hand present in between metacarpals. They are divided into palmar and dorsal interossei. They are discussed as given in Table 30.9. Table 30.9: Palmar and dorsal interossei

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Particulars

Palmar interossei

Dorsal interossei

• Number and morphology

• 4 in number and are unipennate.

• 4 in number and are bipennate.

• Dimension

• 1st palmar interossei is small.

• All dorsal interossei are of uniform size.

• Interossei for middle finger

• Absent.

• They are 2 in number.

• Origin

• 1st and 2nd palmar interossei arise from medial or ulnar surface of respective metacarpals. • 3rd and 4th palmar interossei arise from lateral or radial surface of 4th and 5th metacarpal.

• Adjoining metacarpal.

1. Insertion: Both are inserted on A. Dorsal digital expansion, and B. Base of proximal phalanx of respective finger. 2. Axis: Passes through middle finger. 3. Strength: Palmar interossei are less strong than dorsal interossei. 4. Relations A. They are related posteriorly to deep transverse metacarpal ligaments (Fig. 30.16). B. Radial artery passes between the gap produced by two heads of 1st dorsal interosseous (Fig. 30.17). C. Proximal perforating arteries pass between the gap produced by two heads of 2nd, 3rd and 4th dorsal interossei.

Fig. 30.16: Palmar interossei adductors

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Fig. 30.17: Dorsal interossei abduction

5. Actions PAD, DAB. P=palmar, AD=adductor; D=Dorsal, AB=abductor, B=bipennate A. Palmar interossei are adductors, dorsal interossei are abductors. B. They are powerful flexors of metacarpophalangeal joint (MP) because their tendons are placed ventrally and distally with respect to metacarpophalangeal joint. C. They produce extension of interphalangeal joint. Both these movements are useful for precision work. 6. Nerve supply: They are supplied by deep branch of ulnar nerve. A. Dorsal interossei: By asking to spread the fingers against resistance. B. Palmar interossei: By asking to hold a piece of paper between the testing finger and normal finger. OLA-43 Nerve supply of lumbricals

1. 1st and 2nd lumbricals are supplied by median nerve. 2. 3rd and 4th are supplied by ulnar nerve. OLA-44 Actions of lumbricals

1. Flexion of metacarpophalangeal joint of 2nd to 5th digits. 2. Extension of interphalangeal joint of 2nd to 5th digits.

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7. Testing: Interossei can be tested in following ways.

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Lumbricals

1. Features A. These are worm-like muscles arise from tendons of flexor digitorum profundus. B. They are 4 in number and are present on palmar aspect. C. They are counted from lateral to medial. D. 1st and 2nd lumbricals are unipennate. E. 3rd and 4th lumbricals are bipennate. F. They act as link muscles between deep flexor and extensor tendons of hand. 2. Proximal attachments A. 1st and 2nd lumbricals arise from radial side of profundus tendon, and B. 3rd and 4th lumbricals arise between neighbouring tendons of flexor digitorum profundus.

Fig. 30.18: Origin and insertion of lumbrical

3. Distal attachments: They are inserted on dorsal surface of base of middle and distal phalanx, through lateral border of dorsal digital expansion.

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Fig. 30.19: Morphology of lumbricals

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4. Action: They are flexors of metacarpophalangeal joints and extensors of interphalangeal joints. 5. Nerve supply: Medial two lumbricals are supplied by deep branch of ulnar nerve and lateral two lumbricals are supplied by median nerve. 6. Relations: They are dorsal to digital vessels and nerves. 7. Functions: They produce up and down strokes of fingers for skilled work. They produce flexion at metacarpophalangeal joint and extension of interphalangeal joints. 8. Test: The muscles are best tested by asking the patient to hold a piece of paper between the sides of two adjacent fingers. If the muscles are acting, the paper will be firmly held and some resistance will be offered to its withdrawal. OLA-45 Branches of superficial palmar arch

There are 4 digital branches supply medial 3½ fingers. Out of these 4 digital branches, lateral 3 digital branches are connected with deep palmar arch by palmar metacarpal arteries. LAQ-14 Describe superficial palmar arch under following heads, 1. Arch, 2. Location, 3. Formation, 4. Relations, 5. Branches, and 6. Applied anatomy.

4. Relations A. Anterior a. Palmaris brevis, and b. Palmar aponeurosis.

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Introduction: It is the arterial arch, formed superficial to all the structures in the palm. It is compared with circle of Willis present at base of brain and plantar arterial arch in the foot. 1. Arch: It may be complete. 2. Location: It is situated in distal part of palm and corresponds to distal palmar crease. 3. Formation (Fig. 30.20) A. It is formed on medial side of hand as a continuation of ulnar artery. B. On lateral side, it is completed by one of the following arteries. a. Superficial palmar branch of radial artery, b. Arteria radialis indicis: Artery of index finger (branch of radial artery), c. Arteria princeps pollicis: Artery of thumb (branch of radial artery), and d. Median artery (branch of anterior interosseous artery which is a branch of common interosseous artery—ulnar artery).

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Fig. 30.20: Superficial palmar arch

B. Posterior: a. Flexor digitorum superficialis, b. Flexor digitorum profundus, c. Lumbricals, d. Flexor digiti minimi, and e. Digital branches of median nerve. 5. Branches: There are 4 digital branches supply medial 3½ fingers. Out of these 4 digital branches, lateral 3 digital branches are connected with deep palmar arch by palmar metacarpal arteries.

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6. Applied anatomy

 It is one of the important anastomotic channels for efficient blood supply of palm. It is important in case of blockage of radial or ulnar artery. OLA-46 Branches of deep palmar arch

1. From convexity—3 palmar metacarpal arteries 2. From concavity—recurrent branch 3. Dorsally—3 perforating digital arteries. LAQ-15 Describe deep palmar arch under following heads, 1. Formation, 2. Location,

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3. Arch, 4. Relations, 5. Branches, and 6. Applied anatomy.

Introduction: It is an arterial arch present deep to flexor tendons of digits. 1. Formation: It is mainly formed by radial artery and completed on medial side by deep palmar branch of ulnar artery. 2. Location: It is present at proximal palmar crease. 3. Arch: It may be complete.

Fig. 30.21: Deep palmar arch

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4. Relations A. Anterior a. Oblique head of adductor pollicis, b. Flexor tendons of fingers, and c. Lumbricals. B. Posterior: Shaft of metacarpal and interossei. 5. Branches A. From the convexity of the arch, 3 palmar metacarpal arteries run distally in 2nd, 3rd and 4th spaces. They supply medial 4 metacarpals; terminate in finger cleft by joining with common digital branch of superficial palmar arch. B. From dorsal side, 3 perforating arteries pass through medial 3 interosseous spaces to anastomose with dorsal metacarpal arteries. C. From the convexity of arch, recurrent branch arises to supply carpal bones and ends in palmar carpal arch.

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6. Applied anatomy : It is one of the important anastomotic channels for efficient

blood supply of palm. It is important in case of blockage of radial or ulnar artery. OLA-47 Name the muscles supplied by ulnar nerve in hand

1. 2. 3. 4. 5. 6. 7.

Palmaris brevis, Abductor digiti minimi, Flexor digiti minimi, Opponens digiti minimi, Adductor pollicis, Flexor pollicis brevis (deep head), Interossei, A. 4 palmar, and B. 4 dorsal. 8. Lumbricals: 2 medial.

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4 Fig. 30.22: Ulnar nerve of left hand

LAQ-16 Describe ulnar nerve under following heads 1. Root value, 2. Course and relations, 3. Course in the hand, 4. Branches, and 5. Applied anatomy.

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Introduction: It is the most commonly affected nerve in leprosy in upper limb. It is also called ‘musician’s nerve’ because fine movements of the hand are required to play musical instruments. These are executed by small muscles of hand which are innervated by ulnar nerve. It is the nerve of the flexor muscles present on the medial side of forearm, most of the intrinsic muscles of hand, and skin on medial side of 1½ fingers. 1. Root value: It is the largest branch and direct continuation of medial cord of brachial plexus. The root value is C7, C8 and 1st T nerve. It picks up additional C7 fibres in the axilla, usually from lateral cord.

Table 30.10: Distribution of ulnar nerve Particulars

Muscular

Cutaneous

• Arm

—

—

• Forearm

• Flexor carpi ulnaris • Flexor digitorum profundus (medial half)

—-

• Hand

• Palm: Palmaris brevis • Hypothenar – Abductor digiti minimi brevis – Flexor digiti minimi – Opponens digiti minimi

• Skin of hypothenar eminence and skin of medial one and half fingers.

Joint • Elbow

—

Contd.

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2. Course and relations (Fig. 30.23): The structures in the course and relation of ulnar M nerve begin with the letter A. The medial cord of brachial plexus lies on medial side of 2nd part of axillary artery. B. The ulnar nerve lies medial to 3rd part of axillary artery. C. It also lies medial to brachial artery. D. In the middle of the arm, it pierces medial intramuscular septum along with superior ulnar collateral artery. E. It enters posterior compartment and lies on medial head of triceps. It passes behind medial epicondyle of humerus and is received by flexor carpi ulnaris. F. It lies on medial ligament of elbow joint and rests on medial side of the flexor digitorum profundus under thin blanket of flexor carpi ulnaris in upper 2/3rd of forearm. 3. Course in the hand: It divides on flexor retinaculum into superficial and deep branch. A. The superficial branch runs distally beneath palmaris brevis. B. The deep branch is accompanied by deep branch of ulnar artery and passes in between abductor digiti minimi and flexor digiti minimi, then passes through the substance of opponens digiti minimi. C. It passes down to the interossei, grooves the distal border of hook of hamate, and arches deeply in the palm within the cavity of the deep palmar arch. 4. Branches (Table 30.10)

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Table 30.10: Distribution of ulnar nerve (Contd.) Particulars

Muscular

Cutaneous

• Thenar: – Adductor pollicis – Flexor pollicis brevis (deep head) • Interossei – 4 palmar – 4 dorsal • Lumbricals: 2 medial

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Fig. 30.23: Ulnar nerve of right hand Note: 1. The symbol “ ” at the end of nerve signifies the articular branch 2. The symbol “ ” at the end of nerve signifies the cutaneous branch

Joint

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5. Applied anatomy

 Ulnar nerve is palpated behind medial epicondyle of humerus. This is thickened and is cord-like in Henson’s disease.  Ulnar nerve is damaged  At elbow joint due to • Damage in the cubital tunnel is formed by tendinous arch connecting 2 heads of flexor carpi ulnaris. The ulnar nerve is often entrapped in this tunnel and this entrapment of ulnar nerve in the cubital tunnel is called cubital tunnel syndrome. It results into radial deviation of hand. • Pressure on the ulnar nerve as it passes along ulnar groove. It produces funny sensations along the medial border of forearm, hypothenar surface and little finger. Hence ‘humerus’ is called “funny bone”.  At wrist joint by the compression of volar carpal ligament and palmaris brevis muscle. Guyon’s canal and volar ligament • Here all intrinsic muscles of hand are paralysed resulting into typical claw hand (ulnar claw). • There is a hyperextension of metacarpophalangeal joint of the ring and little finger and flexion of interphalangeal joint. This is because of paralysis of interossei and lumbricals. • There is also loss of sensations on the medial 1½ fingers. • There is loss of adduction of thumb, as adductor pollicis is paralysed. Pulp space

It is space between palmar skin and distal phalanges of all digits of hand. 1. Situation: Distal to fibrous sheath of flexor tendon. 2. Formation: Formed by fibrous septa connecting skin to periosteum of distal phalanx. 3. Contents A. Subcutaneous fat, and B. Blood vessel. 4. Blood supply of terminal phalanx (Fig. 30.24): Distal 4/5th part by digital arteries and proximal part by epiphyseal artery. 5. Applied anatomy

 Infection of pulp space is called whitlow, which is associated with severe throbbing pain due to increased tension in spaces.  Abscess is drained by lateral incision and breaking all septa. In neglected cases, it may lead to avascular necrosis of terminal phalanx. OLA-48 Contents of thenar space

1. Tendons A. Flexor digitorum superficialis of index finger, B. Flexor digitorum profundus of index finger,

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Fig. 30.24: Digital pulp space

C. Flexor pollicis longus, and D. 1st lumbrical. 2. Vessels A. Arteria princeps pollicis, and B. Arteria radialis indicis. 3. Nerves of the thumb and index finger.

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4 Fig. 30.25: Contents of thenar and hypothenar spaces

OLA-49 Muscles of thenar space

1. Flexor pollicis brevis, 2. Abductor pollicis brevis, and 3. Opponens pollicis. OLA-50 Nerve supply of muscles of thenar space

All muscles of thenar eminence are supplied by median nerve except deep head of flexor pollicis brevis which is supplied by deep branch of ulnar nerve.

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Palmar spaces Table 30.11: Palmar spaces

Particulars

Mid-palmar

Thenar

• Introduction

• Hollow space situated on the inner side of palm

• Hollow space situated on outer side of palm

• Shape

•

•

• Situation

• Inner side of palm

• Outer side of palm

• Communication: • Distally

• Fascial sheath of 3rd, 4th lumbricals [occasionally 2nd]

• Fascial sheath of 1st lumbrical [occasionally 2nd]

• Proximally

• The space is closed by the attachment of ulnar bursa to the floor of carpal tunnel

• Boundaries: Anterior

• Skin and palmar aponeurosis

lar

• Flexor tendons of 3rd, 4th, 5th, fingers • 2nd, 3rd, 4th lumbricals

• Lateral • Medial

• Drainage

• Fascia covering interossei and metacarpal • Intermediate palmar septum • Medial palmar septum

• Incision in either the 3rd or 4th web space

• Skin and palmar aponeurosis • Short muscles of thumb flexor pollicis brevis, opponens pollicis, adductor pollicis • Flexor tendon of index finger • 1st lumbrical • Transverse head of adductor pollicis • Lateral palmar septum and radial bursa • Intermediate palmar septum • In 1st web space postteriorly

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• Posterior

lar

Fig. 30.26: Thenar and midpalmar spaces

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OLA-51 Extensor expansion of little finger Table 30.12: Muscles inserted in extensor expansion of little finger Particulars

Little

• • • • •

• • • • •

Extensor digitorum Lumbrical Palmar interossei Another extensor Dorsal interossei

5 4th 4th Extensor digiti minimi Nil

OLA-52 Extensor expansion of ring finger Table 30.13: Muscles inserted in extensor expansion of ring finger Particulars

SN-40

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4

Ring

• Extensor digitorum

•4

• Lumbrical

• 3rd

• Palmar interossei

• 4th

• Dorsal interossei

• 4th

Posterior interosseous nerve

Introduction: It is a deep terminal branch of radial nerve and arises in front of the lateral epicondyle. 1. Peculiarity: It bears a pseudoganglion. 2. Course and relation: The nerve appears in the back of the forearm by piercing the supinator muscle and winds round the lateral side of the radius. 3. Branches (Fig. 30.27) A. Before piercing the supinator a. Extensor carpi radialis brevis, and b. Supinator. B. After piercing the supinator, following branches are given a. Muscular branches I. Short branches to i. Extensor digitorum, ii. Extensor digiti minimi, and iii. Extensor carpi ulnaris. II. Long branches are divided into i. Medial set, which supplies – Extensor pollicis longus, and – Extensor indicis.

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Fig. 30.27: Branches of posterior interosseous nerve

ii. Lateral set, which supplies – Abductor pollicis longus, and – Extensor pollicis brevis. b. Articular branches to I. Wrist joint, II. Inferior radioulnar joint, and III. Intercarpal joints. c. Sensory branches I. Interosseous membrane, II. Radius, and III. Ulnar.

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31 Joints of Upper Limb

OLA-53 Name the factors stabilizing shoulder joint

The stability of shoulder joint mainly depends upon surrounding muscles 1. Rotator cuff A. Supraspinatus, B. Infraspinatus, C. Teres minor, and D. Subscapularis. 2. Long head of biceps being intracapsular stabilizes the joint from inside the capsule. 3. Long muscles of shoulder A. Deltoid—laterally B. Long head of triceps—medially C. Pectoralis majoranteriorly D. Latissimus dorsi—posteriorly OLA-54 Name the muscles causing adduction at shoulder joint

1. Sternal head of pectoralis major, and 2. Latissimus dorsi. OLA-55 Muscles causing lateral rotation at shoulder joint.

Lateral rotators are TIP Teres minor, Infraspinatus, and Posterior fibres of deltoid. OLA-56 Muscles causing medial rotation at shoulder joint

1. Medial rotators are (“ 1. Latissimus dorsi, 2. Pectoralis major,

Lady, majors and soldier”)

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3. Teres major, and 4. Subscapularis. LAQ-17 Describe intrinsic muscles of hand

1. Features A. The intrinsic muscles of the hand serve the function of adjusting the hand during gripping and also for carrying out fine-skilled movements. B. The origin and insertion of these muscles is within the territory of the hand. C. There are 20 muscles in the hand. These are a. Three muscles of thenar eminence I. Abductor pollicis brevis, II. Flexor pollicis brevis, and III. Opponens pollicis. b. One adductor of thumb: Adductor pollicis. c. Four hypothenar muscles I. Palmaris brevis, II. Abductor digiti minimi, III. Flexor digiti minimi, and IV. Opponens digiti minimi. d. Muscles of hypothenar eminence. I. Abductor digiti minimi, II. Flexor digiti minimi, and III. Opponens digiti minimi e. Four lumbricals, f. Four palmar interossei, and g. Four dorsal interossei. Branches of ulnar nerve in hand

1. Ulnar nerve divides into A. Superficial, and B. Deep branches on the flexor retinaculum. A. The superficial branch runs beneath palmaris brevis to which it supplies. It has two digital branches: a. One supplies the ulnar 1½ fingers, including their nail beds. b. The other supplies the skin on the dorsum of the hand not supplied by the dorsal branch. B. Deep branch is joined by deep branch of ulnar artery. a. It passes deeply between abductor and flexor digiti minimi. b. It passes through opponens digiti minimi and supplies all the hypothenar muscles. c. It crosses the palm in the concavity of deep palmar arch.

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d. It supplies medial two ulnar lumbricals and, both palmar and dorsal interossei. e. It ends its journey by resting peacefully—in adductor pollicis—the grave yard of ulnar nerve. (ATM—Aid to Memory) 2. The muscles supplied by ulnar nerve in hand are subdivided into muscles of A. Hypothenar, and B. Thenar eminence. A. The muscles of hypothenar eminence are remembered by a key word Box 31.1 I ate a LOAF. The word loaf means—A shaped mass of bread baked in one piece. The expansion of key word is * I for interossei * Ate represents ‘eight.’ * Though both words are different, they sound the same. * L stands for Lumbricals * O denotes Opponens digiti minimi * A represents Abductor digiti minimi. * F represents Flexor digiti minimi.

B. The muscles of the thenar eminence are a. Deep head of flexor pollicis brevis, and b. Adductor pollicis. 3. Applied anatomy

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 Cervical rib: Pressure of cervical rib on the lowest trunk of the brachial plexus may produce – Wasting of the small muscles of the hand. – Paresthesia along the ulnar border of the forearm.  Ulnar nerve is most commonly injured behind the elbow or at the wrist.  The classical sign of a low lesion is claw hand. There is – Hyperextension of metacarpophalangeal joints of the ring and little fingers, and – Flexion of interphalangeal joints. – The interossei and lumbricals of ring and little fingers are paralyzed, so flexion at metacarpophalangeal joint and extension at interphalangeal joint are affected. – The claw hand is produced by the unopposed action of the extensors and of flexor digitorum profundus.  Injury at the elbow or above gives straighter fingers because the ulnar ½ of the flexor digitorum profundus is out of action and cannot flex the distal interphalangeal joints of the ring and little fingers. – Wasting of interossei eventually becomes obvious on the dorsum of hand, giving the appearance of guttering between the metacarpals.

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 Testing for abduction of the index finger by the first dorsal interosseous assesses small muscle function in the hand that is dependent on the intact ulnar nerve supply.  The integrity of the ulnar nerve can be confirmed by testing the sensations of the pulp of little finger

.

 Cubital tunnel is the site for ulnar nerve entrapment. Nerve entrapment is the compression of a nerve causing slowing of conduction and variable degree of demyelination.  When ulnar nerve is rolled in the groove between medial epicondyle of humerus and olecranon process of ulna, one feels tingling sensations in his/her ring and little fingers. The person often goes crazy to do so repeatedly. Hence, the humerus bone is called ’crazy bone (funny bone)’. SN-42

Coracoacromial arch

Introduction: The coracoacromial arch is an extrinsic, protective structure. 1. Formation: It is formed by A. Acromion, B. Coracoacromial ligament, and C. Coracoid process. 2. Synonymous: Secondary socket for the head of the humerus. 3. Functions A. It adds stability to the joint, and B. Protects the head of the humerus. C. The subacromial bursa facilitates movement between the coracoacromial arch and the subjacent supraspinatus and shoulder joint. Thus, it functions as a secondary synovial articulation. 4. Structures deep to coracoacromial arch A. Supraspinatus muscle, and B. Subacromial bursa. 5. Applied anatomy

 Osteoarthritis or thickening of coracoacromial arch results in impingement syndrome or painful arc syndrome. This is characterised by pain in abduction of the shoulder between 60° and 120°.  The coracoacromial arch is so strong that a forceful superior thrust of the humerus will not fracture it. Excessive pressure may fracture humerus or clavicle but not coracoacromial arch.

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D. It prevents upward dislocation of shoulder.

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LAQ-18 Describe shoulder joint or glenohumeral joint under following heads 1. Classification, 2. Ligaments, 3. Movements, 4. Relations, 5. Blood supply, 6. Nerve supply, 7. Applied anatomy, and 8. Stability of shoulder joint

1. Classification A. Structural: AB’S a. Axis: Multiaxial b. Number of bones: 2. Hence it is simple. c. Shape: Ball and socket type of synovial joint

.

B. Functional: Diarthrosis.

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2. Ligaments A. Capsule a. Attachments to I. Humerus: It is attached to anatomical neck of humerus except medially. II. Scapula: It is attached to peripheral margins of glenoid cavity. It includes supraglenoid tubercle but excludes infraglenoid tubercle. b. Deficient: It is deficient in the region of bicipital groove for the passage of I. Tendon of long head of biceps, II. Synovial sheath, III. Ascending branch of anterior circumflex humeral artery. c. Laxity: It is lax on the inferior side, 1 cm below the surgical neck of humerus. d. Strengthened: It is strengthened by rotator cuff, i.e. I. Supraspinatus, II. Infraspinatus, III. Teres minor, and IV. Subscapularis. e. Capsule has two openings for I. Long head of biceps muscle, and II. Subscapular bursa. B. Synovial membrane: It lines inner surface of capsule and extends on long head of biceps, as tubular extension. It communicates with synovial membrane of subscapular bursa.

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C. Glenoid labrum: Structurally it is fibrocartilage in nature and section. It is attached to peripheral margin of glenoid cavity.

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lar in cross-

a. It deepens the cavity of shoulder joint. b. It protects the edges of the articulating surfaces. c. It provides the cushion to head of humerus to roll as ball bearing. D. Glenohumeral ligament (It is condensation of anterior part of capsule). It extends superiorly from superomedial margin of glenoid cavity. Inferiorly, it is attached to three attachments: a. Superior band is attached to upper end of lesser tubercle. b. Middle band is attached to lower end of lesser tubercle. c. Inferior band is attached to lower part of anatomical neck. E. Coracohumeral ligament: It is thick band in the upper part of fibrous capsule. It extends from the root of coracoid process to neck of humerus. F. Transverse humeral ligament: Bridges greater and lesser tubercles.

D. Adduction a. Sternal fibres of pectoralis major, and b. Latissimus dorsi. Lady, soldier and majors are medial rotators, i.e. muscles E. Medial rotation: forming posterior boundaries of axilla, namely Latissimus dorsi, Subscapularis, 2 majors (pectoralis major and teres major), and Anterior fibres of deltoid.

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3. Movements A. Flexion a. Anterior fibres of deltoid, and b. Clavicular fibres of pectoralis major. B. Extension a. Posterior fibres of deltoid with b. Latissimus dorsi. C. Abduction a. For every 15° of abduction, 10º occurs at shoulder joint and 5º at shoulder girdle b. 1–15º: Supraspinatus c. 15–90º: Middle fibres of deltoid (acromial). Note: Supraspinatus and deltoid act between 0° and 90° (Gray’s 40th edition) d. 90º–120º by fibres of serratus anterior attached to inferior angle of scapula. e. 120º–180º is by serratus anterior through shoulder girdle.

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F. Lateral rotation

TIP

Teres minor, Infraspinatus, and Posterior fibres of deltoid. G. Circumduction (combination of movements): Abduction of flexed joint. 4. Relations (Fig. 31.1) A. Superiorly a. Coracoacromial arch, b. Subacromial bursa, c. Supraspinatus, and d. Deltoid. B. Inferiorly: Long head of triceps C. Anteriorly: a. Subscapularis, b. Coracobrachialis, . c. Short head of biceps, and d. Clavicular fibers of deltoid. D. Posteriorly a. Posterior fibres of deltoid, b. Infraspinatus, and c. Teres minor. E. Intracapsular: Tendon of long head of biceps.

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Fig. 31.1: Relations of shoulder joint

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5. Blood Supply A. Anterior circumflex humeral artery,  B. Posterior circumflex humeral artery,  Branches of axillary artery  C. Subscapular artery, D. Suprascapular artery: Branch of thyrocervical trunk—branch of 1st part of subclavian artery. 6. Nerve supply A. It is mainly from the posterior cord of brachial plexus through the subscapular nerve. B. The capsule is supplied by a. Suprascapular nerve (posterior and superior part) b. Axillary nerve (anteroinferior part) c. Lateral pectoral nerve (anterosuperior part) 7. Applied anatomy

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 Shoulder joint is the most frequently dislocating joint in the body. It is due to  Disproportionate articular surfaces of head of humerus and glenoid cavity of scapula, and  Laxity of capsule: Capsule is lax inferiorly hence inferior dislocation is most common.  It usually occurs when arm is forcefully abducted. Axillary nerve is usually injured.  Frozen shoulder (adhesive capsulitis): It is a common condition due to adhesion between two layers of synovial membrane. It is scarring between inflamed joint capsule of the glenohumeral joint, rotator cuff, subacromial bursa, and deltoid.  Shoulder tip pain: Irritation of diaphragm causes referred pain to the shoulder tip  The skin over shoulder joint is supplied by supraclavicular nerve. The diaphragm is supplied by phrenic nerve. The root values of phrenic nerve and supraclavicular nerve are same, i.e. C3 and C4 of spinal segment. Therefore, the pain of diaphragm is referred to tip of shoulder. 8. Stability of shoulder joint The stability of shoulder joint mainly depends upon surrounding muscles. A. Rotator cuff a. Supraspinatus, b. Infraspinatus, c. Teres minor, and d. Subscapularis. B. Long head of biceps being intracapsular stabilizes the joint from inside the capsule. C. Long muscles of shoulder a. Deltoid laterally, b. Long head of triceps medially, c. Pectoralis major anteriorly, and d. Latissimus dorsi posteriorly.

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OLA-57 Name the flexors of the elbow joint

1. Main flexors A. Brachialis, B. Biceps brachii, and C. Brachioradialis 2. Other flexors A. Pronator teres, B. Flexor carpi radialis, C. Palmaris longus, D. Flexor digitorum superficialis, and E. Flexor digitorum profundus. SN-43

Anastomosis around the elbow joint

Introduction: It is an important communication between brachial and the terminal branches of brachial artery (radial and ulnar arteries). 1. Distribution: It supplies A. Ligaments, B. Bones of the elbow region, C. Elbow joint, and D. Superior radioulnar joint.

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Fig. 31.2: Anastomosis around the elbow joint

2. Division A. In front of the lateral epicondyle of the humerus: The anterior descending branch (radial collateral artery), branch of profunda brachii, anastomoses with the radial recurrent artery, branch of radial artery.

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B. Behind the lateral epicondyle of the humerus: The posterior descending artery, a branch of the profunda brachii artery, anastomoses with the interosseous recurrent artery, branch of the posterior interosseous artery. C. In front of the medial epicondyle of the humerus: The inferior ulnar collateral branch of the brachial artery anastomoses with the anterior ulnar recurrent branch of ulnar artery. D. Behind the medial epicondyle of the humerus: The superior ulnar collateral branch of the brachial artery anastomoses with the posterior ulnar recurrent branch of ulnar artery. E. Just above the olecranon fossa: A branch from posterior descending artery, a branch of the profunda brachii artery, anastomoses with the branch from the inferior ulnar collateral artery. LAQ-19 Describe elbow joint under following heads 1. Classification, 2. Ligaments, 3. Movements, 4. Relations, 5. Blood supply, 6. Nerve supply, and 7. Applied anatomy.

1. Classification A. Structural: AB’S B. Axis: Uniaxial. Since the axis is horizontal, it is hinge variety. C. Number of bones are 3, it is compound variety of synovial joint. D. Functional: It is freely movable, therefore, it is diarthrosis. E. Cubital articulation: Consists of three joints.

Particulars

Humero-radial joint

Humero-ulnar joint

• Bones

• Humerus and radius

• Humerus and ulna

• Articular surface

• Head of radius with capitulum of humerus

• Trochlear notch of ulna with trochlear surface of humerus

• Type

• Ball and socket type of synovial joint

• Saddle type of synovial joint

2. Ligaments A. Fibrous capsule: It is attached to peripheral margin of articular surface of humerus, radius and ulna. a. It is thick medially, thick laterally, thin anteriorly, and thin posteriorly. b. Excludes medial and lateral epicondyles.

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Table 31.1: Bones forming the elbow joint

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c. Includes three fossae: Coronoid, radial and olecranon. d. Merges with the annular ligament of superior radioulnar joint. B. Synovial membrane—lines inner surface of capsule C. Anterior and   formed by thickening of capsule of elbow joint and is thin. Posterior ligaments  D. Ulnar collateral ligament is lar in shape. It extends superiorly from lower part of medial epicondyle. Inferiorly it divides into three bands a. Anterior band is attached to medial margin of coronoid process. b. Inferior band is attached between olecranon and coronoid process. c. Posterior band is attached to medial margin of olecranon process. E. Radial collateral ligament: It extends from lateral epicondyle of humerus to annular ligament. 3. Movements Table 31.2: Movements and the muscles bringing the movements Movements

Muscles producing movement

Other muscles

• Flexion

• Brachialis • Biceps • Brachioradialis

• • • • •

• Extension

• Triceps • Anconeus

• Extensor carpi radialis longus and brevis • Extensor carpi ulnaris, • Extensor digitorum

Palmar teres, Palmar longus, Flexor digitorum superficialis, Flexor carpi radialis, Flexor carpi ulnaris

4. Relations (Fig. 31.3)

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A. Anteriorly a. Brachialis,  b. Tendon of biceps,  Structures are contents of cubital fossa c. Median nerve,  d. Brachial artery, B. Posterior: Triceps, anconeus. C. Medially a. Ulnar nerve, b. Flexor carpi ulnaris, and c. Common flexors of forearm. D. Laterally a. Supinator, b. Extensor carpi radialis brevis muscle,

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Fig. 31.3: Relations of the structure above the elbow joint

c. Common extensors, and d. Brachioradialis muscle (Fig. 31.3). 5. Blood supply A. Superior ulnar collateral artery  B. Inferior ulnar collateral artery  Branches of brachial artery  C. Anterior descending artery  Branches of profunda brachii artery  D. Posterior descending artery E. Radial recurrent artery, branch of radial artery F. Interosseous recurrent artery, branch of common interosseous artery G. Anterior ulnar recurrent artery   H. Posterior ulnar recurrent artery  Branches of ulnar artery 6. Nerve supply Musculocutaneous nerve, Radial nerve, Median nerve, and Ulnar nerve.

7. Applied anatomy

 Supracondylar fractures result into Volkmann’s ischaemic contracture which is due to injury to brachial artery.  Usually the elbow joint dislocates posteriorly. It is associated with fracture of coronoid process.  Effusion of joint occurs posteriorly because capsule is weak posteriorly.  Tennis elbow: Pain and tenderness over lateral epicondyle is due to  Sprain of radial collateral ligament.  Tearing of the fibers of extensor carpi radialis brevis.  Inflammation of bursa over the extensor carpi radialis brevis.

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A. B. C. D.

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SAQ-5

Carrying angle

Introduction: It is an angle formed by arm with forearm when elbow is fully extended and forearm supinated, which opens laterally. 1. Cause: There are two reasons A. Medial flange of trochlea is 6 mm is lower than lateral flange of trochlea. B. Obliquity of superior articular surface. 2. Gender difference: There is no much difference in the carrying angle in male and female . It is less than 10° in male and more than 15° in female. 3. Function: Carrying angle is helpful in holding the object. 4. Degree of angle (Fig. 31.4) A. It is 163o in fully extended elbow and supinated forearm. B. It is 0o in full flexion and pronation of forearm.

Fig. 31.4: Carrying angle

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OLA-58 Name the movements at radioulnar joints and muscles causing them

1. Supination A. Biceps brachii—strong supinator B. Supinator 2. Pronation A. Pronator teres B. Pronator quadratus SN-44

Radioulnar joints

1. Radioulnar joints 2. There are three joints formed by radius and ulna. They are A. Superior radioulnar joint, B. Middle radioulnar joint, and C. Inferior radioulnar joint (Table 31.3).

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Table 31.3: Superior and inferior radioulnar joints Superior radioulnar joint

Inferior radioulnar joint

• Classification of joints depending upon the number of bones

• Simple synovial

• Classification based upon axis

• Uniaxial

• Classification depending upon direction of axis

• Pivot type of synovial joint

• Articulate surfaces

• Circumference of head of radius • Osseofibrous ring, formed by the radial notch of the ulna and the annular ligament

• Head of ulna • Ulnar notch of radius

• Ligaments

• Annular ligament. It forms 4/5th of the ring within which the head of the radius rotates. It is attached to the margins of the radial notch of the ulna and is continuous with the capsule of the elbow joint above. • Quadrate ligament extends from the neck of the radius to the lower margin of the radial notch of ulna.

• Capsule surrounds the joint. The weak upper part is evaginated by the synovial membrane to form a recess (recess sacciformis) in front of the interosseous membrane • The apex of lar fibrocartilaginous articular disc is attached to the base of the styloid process of the ulna, and the base to the lower margin of the ulnar notch of the radius

• Blood supply

• Anastomoses around the lateral side of the elbow joint

• Anterior and posterior interosseous arteries

• Nerve supply

• Musculocutaneous, • Median, and • Radial nerves

• Anterior interosseous nerve, branch of median nerve and posterior interosseous nerve, branch of radial nerve

• Movements

• Supination and pronation

3. Middle radioulnar joint A. Classification: Syndesmosis type of fibrous joint. B. Articulate surfaces: Interosseous boders of radius and ulna. C. Ligaments: a. Interosseous membrane: It connects the shafts of the radius and ulna. b. Oblique cord: It extends from the tuberosity of the radius to the tuberosity of the ulna connecting the two bones.

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Features

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4. Features Table 31.4: Anatomical classification of joint Joint

Classification of joint

Articulating surface of radius

Articulating surface of corresponding bone

• Elbow joint

• Compound, hinge variety of synovial joint

• Superior surface of upper end of radius

• Capitulum of humerus

• Superior radioulnar joint

• Uniaxial pivot variety of synovial joint

• Circumference of head of radius

• Radial notch of ulna

• Middle radioulnar joint

• Syndesmosis type of fibrous joint

• Interosseous border of radius

• Interosseous border of ulna

• Inferior radioulnar joint

• Uniaxial pivot variety of synovial joint

• Ulnar notch of radius

• Head of radius

• Wrist joint

• Biaxial, ellipsoid type of synovial joint

• Inferior surface of lower end of radius

• Proximal surfaces of scaphoid, lunate and triquetral

Radius and the ulna are joined to each other at the superior and inferior radioulnar joints. Radius and ulna are also connected by the interosseous membrane which constitutes middle radioulnar joint. SN-45

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Interosseous membrane

1. Features A. It connects the shafts of the radius and ulna. B. It is attached to the interosseous borders of these bones. C. The fibres of the membrane run downwards and medially from the radius to ulna. 2. Extent A. Superiorly, the interosseous membrane begins 2–3 cm below the radial tuberosity. Between the oblique cord and the interosseous membrane, there is a gap for passage of the posterior interosseous vessels to the back of the forearm. B. Inferiorly, a little above its lower margin, there is an aperture for the passage of the anterior interosseous vessels to the back of the forearm. 3. Relations of interosseous membrane A. Anterior surface is related to the a. Flexor pollicis longus, b. Flexor digitorum profundus, c. Pronator quadratus, and d. Anterior interosseous vessels and nerve.

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B. Posterior surface is related to the a. Supinator, b. Abductor pollicis longus, c. Extensor pollicis brevis, d. Extensor pollicis longus, e. Extensor indicis, f. Anterior interosseous artery, and g. Posterior interosseous nerve. 4. Functions A. It binds the radius and ulna to each other. B. It provides attachments to many muscles. C. It transmits force. LAQ-20 Describe supination and pronation under following heads 1. Mechanism of action, and 2. Applied anatomy

Introduction: Supination and pronation movements are mainly evolved for picking up the food and keeping into mouth. Table 31.5: Comparison between supination and pronation Supination

Pronation

• Introduction: – In anatomical position – In mid flexion of elbow joint

• Palm faces forward and thumb faces laterally • Palm faces upwards and thumb faces laterally

• Palm faces backwards and thumb faces medially • Palm faces downwards and thumb faces medially

• Position of bone • Interosseous membrane

• Radius is laterally, ulna is medially and both are kept parallel to each other • Not spiraled

• Position of radius and ulna remains same. Radius is anteromedially, ulnaris laterally in upper 1/2, while it is reverse in lower 1/2 • Spirally twisted

• Movement of bone

• Radius plays active role and ulna remains more or less fixed

• Head of radius rotates in the fibroosseous ring, a pivot joint • Lower end of radius and articular disc swing around ulnar head

• Strength • Position of axis

• Greater • Displaced medially

• Lesser • Displaced laterally

• Situations in which these movements are used • Relation to gravity

• Tightening of nuts picking the food

• Loosening of nuts

• Antigravity action

• Towards gravity

• Muscles producing movements

• Biceps brachii (strong supinator) • Supinator

• Pronator teres • Pronator quadratus

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Particulars

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Exam-Oriented Anatomy

1. Mechanism of action (Figs 31.5 and 31.6) A. Position of forearm is semiflexed. B. Type of movement is rotatory. C. Evolved for picking up food and putting into mouth. D. Range of movements: a. In flexed elbow: 140°–150° b. In extended elbow: 360°. It includes rotation of shoulder. E. Axis: a. Plane: Transverse. b. Representation: It is represented as axis passing through centre of head of radius and apex of articular disc to little finger. F. Homologous movements in lower limb: Inversion and eversion G. Joints: Superior and inferior radioulnar joints.

Fig. 31.5: Supination and pronation

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Fig. 31.6: Kings pronate and beggars supinate

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2. Applied anatomy

 In children, head of radius is not developed as compared to annular ligament. Hence, subluxation of superior radioulnar joint is common under age of 6 years.  Pronation and supination movements are used in mechanical jobs, e.g. tightening screw with screw driver. OLA-59 Classify the radioulnar joints

1. Anatomical classification Table 31.6: Anatomical classification of joint Joint

Classification of joint

Articulating surface of radius

Articulating surface of corresponding bone

• Superior radioulnar joint

• Uniaxial pivot variety of synovial joint

• Circumference of head of radius

• Radial notch of ulna

• Middle radioulnar joint

• Syndesmosis type of fibrous joint

• Interosseous border of radius

• Interosseous border of ulna

• Inferior radioulnar joint

• Uniaxial pivot variety of synovial joint

• Ulnar notch of radius

• Head of radius

OLA-60 Bones forming wrist joint

1. Inferior surface of lower end radius, 2. Proximal surface of A. Scaphoid, B. Lunate, and C. Triquetral. LAQ-21 Describe wrist joint (radiocarpal) under following heads 2. Classification, 3. Ligaments, 4. Relations, 5. Movements, 6. Blood supply, 7. Nerve supply, and 8. Applied anatomy.

1. Bones taking part A. Proximally a. Distal articular surface of the radius, and b. Articular disc of inferior radioulnar joint.

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1. Bones taking part,

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Exam-Oriented Anatomy

B. Distally a. Scaphoid, lunate, triquetral bone, and b. Interosseous ligament. In neutral position of the wrist, only the scaphoid and lunate are in contact with the radius and articular disc. The triquetrum comes in contact only in full adduction of wrist joint. 2. Classification A. Structural ABS a. Axis: Biaxial b. Number of bones are 4, forming compound joint c. Shape: Ellipsoid variety of synovial joint B. Functional: Diarthrosis. 3. Ligaments (Fig. 31.7) A. Capsule a. Attachments I. Proximally: It is attached close to the peripheral margin of inferior surface of distal end of i. Radius and ii. To the margins of articular disc, and iii. Styloid process of ulna. II. Distally: It is attached to proximal surface of i. Scaphoid, ii. Lunate, and iii. Triquetral. b. Capsule is thickened to form by following ligaments I. Palmar radiocarpal, II. Palmar ulnocarpal, III. Dorsal radiocarpal, IV. Radial collateral, and V. Ulnar collateral. c. Features I. It blends with the palmar and dorsal radiocarpal ligaments. II. It is lined by synovial membrane. III. It is separate from distal radioulnar and intercarpal joint. IV. A recess is present anterior to articular disc. It ascends close to styloid process of radius. It is called recessus sacciformis. B. Radial collateral ligament: It is thickening of lateral part of capsule. It extends from styloid process of radius to the scaphoid and trapezium. C. Ulnar collateral ligament: It extends from styloid process of ulna to the triquetral and pisiform bone.

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Fig. 31.7: Ligaments of wrist joint

4. Relations (Fig. 31.8) A. In front: The tendons are arranged in three groups (from lateral to medial). They are a. Superficial I. Flexor carpi radialis, II. Palmaris longus, and III. Flexor carpi ulnaris. b. Intermediate I. Radial artery, II. Median nerve, and MR

(Tendons of middle and ring fingers are arranged superficially and tendons of index and little fingers are arranged deeply). c. Deep: Flexor pollicis longus, anterior interosseous vessels and nerve, flexor digitorum profundus. B. Behind: Beneath extensor retinaculum, there are 6 osseofibrous compartments. These are arranged from lateral to medial as a. 1st compartment I. Abductor pollicis longus II. Extensor pollicis brevis b. 2nd compartment I. Extensor carpi radialis longus II. Extensor carpi radialis brevis c. 3rd compartment

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III. Flexor digitorum superficialis

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I. Extensor pollicis longus II. Tubercle of Lister d. 4th compartment I. Extensor digitorum and II. Extensor indicis, III. Posterior interosseus nerve, and IV. Anterior interosseus artery. e. 5th compartment: Extensor digiti minimi f. 6th compartment: Extensor carpi ulnaris.

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Fig. 31.8: Relations of wrist joint

5. Movements A. Movements of wrist joint are associated with movements of midcarpal joint because they are produced by same group of muscles. B. Combination of wrist and mid-carpal joint is called link joint. Joint Movements

READ

a. Radiocarpal: Extension and Adduction. In Radiocarpal joint, the movements are Extension and Adduction. b. Midcarpal: Flexion and abduction. In midcarpal joint, the movements opposite to radiocarpal occur.

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Table 31.7: Muscles bringing movements Range of movements

Main joint at which movements take place

Main muscles

Accessory muscles

• Flexion

•85 º

• Midcarpal

• Flexor carpi radialis and flexor carpi ulnaris

• Flexor digitorum superficialis • Flexor digitorum profundus • Flexor pollicis longus

• Extension

•60 º

• Radiocarpal (wrist)

• Extensor carpi radialis • Longus and brevis

• Extensor digitorum • Extensor indicis, • Extensor pollicis longus • Extensor digiti minimi

• Abduction •15 º (Abduction is restricted than the adduction)

• Midcarpal

• Abductor pollicis longus

• Flexor carpi radialis • Extensor carpi radialis • Longus and brevis

• Adduction

• Radiocarpal

• Flexor carpi ulnaris and extensor carpi ulnaris

•45º

6. Blood supply A. Palmar carpal arch, and B. Dorsal carpal arch which is derived from a. Anterior interosseous artery, b. Posterior interosseous artery, c. Anterior carpal (branch of radial and ulnar arteries), d. Posterior carpal (branch of radial and ulnar arteries), and e. Recurrent branches of deep palmar arch. 7. Nerve supply A. Anterior interosseous nerve (branch of median nerve), and B. Posterior interosseous nerve (branch of radial nerve). 8. Applied anatomy

 Colles’ fracture (dinner fork deformity, Fig. 31.9)  It is due to fall on outstretched hand,  It involves distal end of radius,  Here fracture is transverse,  Force displaces the lower segment upwards and backwards, and  Distal articular surface is inclined posteriorly.

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Movements

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Fig. 31.9A: Colles’ fracture

Fig. 31.9B and C: Colles’ fracture of distal radius

Box 8.2  Cause, site, age group and clinical manifestations of Colles’ fracture by “D”  Site: It is a fracture of Distal part of radius.  Cause: It is due to fall on outstretcheD hand.  Age—ElDerely due to osteoporosis  Manifestations:  It presents as Dorsally Displaced hand,  Dorsally angulated  Physical examination shows Deformed Dinner fork hand.  Patient has tenderness at Distal part of forearm.  Treatment:  In stable condition, closed reDuction and cast.  In unstable condition, open reduction with internal fixation.  Closed reduction with percutaneous pinning.

 Smith’s fracture: It is reverse of Colles’ fracture:  It is produced by fall on the back of hand.  Here distal fragment is displaced forward and upward.

Upper Limb

4

OLA-61 Name the movements at metacarpophalangeal joint of middle finger and muscles causing them

Movements at metacarpophalangeal joint of middle finger 1. Flexion: A. Flexor digitorum superficialis, and B. Flexor digitorum profundus. 2. Extension: Extensor digitorum. SN-46

First carpometacarpal joint

1. Classification A. Structurally: Biaxial, saddle variety of synovial joint. B. Functionally: Diarthrosis.

Joints of Upper Limb

375

2. Articular surfaces A. Distal surface of trapezium, and B. Proximal surface of base of first metacarpal. 3. Ligament A. Capsular ligament: Surrounds the joint. It is thickest, dorsally and laterally, B. Lateral ligament: Broad band, which thickens capsule, C. Anterior ligament, and D. Posterior ligament.

Fig. 31.10: Carpometacarpal joint of thumb

4. Relations A. Anterior: Muscles of thenar eminence. B. Dorsally: Long and short extensor of thumb. C. Medially: First dorsal interossei muscle. D. Laterally: Abductor pollicis longus. 6. Movements: Flexion and extension are parallel to the plane of palm. Abduction and adduction movements are perpendicular to the plane of palm. Opposition is adduction with medial rotation. A. Flexion: Flexor pollicis brevis. B. Extension: Abductor pollicis longus. Extensor pollicis brevis. C. Abduction: Abductor pollicis brevis. Abductor pollicis longus. D. Adduction: Adductor pollicis. E. Opposition: Opponens pollicis. 7. Applied anatomy

 The 1st carpometacarpal joint can undergo degenerative changes with age which is a painful condition of the base of the thumb.

4 Upper Limb

5. Nerve supply : Median nerve

Exam-Oriented Anatomy

376

 The synovial lining of the tendons of extensor pollicis brevis and abductor pollicis longus can get inflamed. It is due to repetitive strain. It can lead to a painful condition called de Quervains tenosynovitis. Movement of the thumb can aggravate pain in this condition. SN-47

Upper Limb

4

Tennis elbow

Definition: It is the inflammation of extensor tendons arising from lateral epicondyle. It is due to overuse of extensor muscles of forearm 1. The cause is not known, but it is seldom due to tennis. 2. Incidence: Common in players of lawn tennis or table tennis. A. It is most common cause of elbow pain in orthopaedic clinics. 3. Common in A. Tennis players, B. Violinists, and C. Housewives. 4. Structure involved: The extensor muscles of forearm. 5. It is precipitated by A. Small minor trauma to the origin of the extensor tendons. B. Usually there is a history of unaccustomed activity such as a. House painting, or b. Carpentry. 6. Cause: The pain may be due to damage of following structures A. Degeneration or tearing of the fibres of extensor carpi radialis brevis muscle mainly, B. Sprain of radial collateral ligament, C. Inflammation of periosteum around lateral epicondyle, and D. Partial tearing or degeneration of the origin of the superficial extensor muscles. 7. Clinical manifestation A. Symptoms: Pain is felt over the lateral epicondyle. It radiates to posterior surface of the forearm. Pain is due to inflammation of the a. Ligament: Radial collateral ligament. b. Bone: Periosteum around its attachment to the lateral epicondyle. c. Muscle I. Tearing of the fibres of extensor carpi radialis brevis muscle (main) II. Strain or tear of common extensor origin. d. Bursa: Inflammation of the bursa underneath the extensor carpi radialis brevis. e. It is aggravated by movements such as I. Lifting a glass, II. Pouring out tea, III. Turning a stiff door-handle,

Joints of Upper Limb

377

IV. Opening a door, and V. Shaking hands or lifting with the forearm pronated. B. On examination a. The elbow looks normal, b. Flexion and extension are full and painless, c. Characteristically there is localized tenderness just below the lateral epicondyle, d. Pain can be reproduced by I. Passively stretching the wrist extensors, or II. Actively extending the wrist with the elbow straight. 8. Treatment A. Rest, B. Avoid precipitating activity, to allow the lesion to heal. C. In cases of severe pain, a mixture of methyl prednisolone and lignocaine is injected at the site. D. The surgery is advised in persistent cases. Box 31.3 N.B: The ‘medical term’ for tennis elbow is lateral epicondylitis, i.e. inflammation of the tissues surrounding the lateral epicondyle of the humerus. The tennis elbow is by far the most common cause of elbow pain in patients attending orthaopaedic clinics. SN-48

Compare upper limb with lower limb

Originally all the four limbs were used for locomotion. They have the same basic pattern, e.g.; the palm and sole have histologically thick skin. As they serve different functions, there are some differences. Table 31.8: Compare of upper limb with lower limb

Development

Upper limb

Lower limb

• Develop

• 2 days earlier to lower limb

• 2 days later to upper limb

• Embryonic limb buds

• Rotate laterally

• Rotate medially

• Preaxial border

• Lies laterally

• Preaxial border (great toe side) lies medially and postaxial border lies laterally

• Postaxial border

• Lies medially

• Preaxial bone

• Radius

• Tibia Contd.

4 Upper Limb

Particulars

Exam-Oriented Anatomy

378

Table 31.8: Compare of upper limb with lower limb (Contd.) Particulars

Upper Limb

4

Upper limb

Lower limb

• Postaxial bone

• Ulna

• Fibula

• Joint

• Elbow lies posteriorly

• Knee faces anteriorly

• Extensor muscles

• Posteriorly

• Anteriorly

• Flexor muscles

• Anteriorly

• Posteriorly

• Alignment of distal parts

• Hand is aligned along the axis of the limb

• Foot is placed at right angle with the axis of the lower limb

• Function

• Grasping and skilled movement

• Weight bearing and locomotion

• Size

• Smaller and shorter

• Larger and longer

• Bones

• Smaller and weaker

• Larger and stronger

• Total no. of bones

• 32

• 31

• Muscles

• Smaller and attached to smaller bony areas

• Larger and attached to larger bony areas

• Antigravity muscles

• Less developed

• Well developed

• 3 segments

• Proximal (arm), • Middle (forearm), and • Distal (hand)

• Proximal (thigh), • Middle (leg) and • Distal (foot)

• No. of bones

• Single bone in the proximal segment (humerus), • Bones in the middle segment (radius and ulna), and • Group of small bones in distal segment (8 carpals)

• Single bone in the proximal segment (femur), • Bones in the middle segment (tibia and fibula) and group of small bones in distal segment (7 tarsals)

• Mobility

• Less firmly attached to the trunk and more mobile

• More firmly attached to the trunk and less mobile

• Girdle

• Pectoral girdle is made up of 2 bones: clavicle and scapula

• Pelvic girdle is made up of single bone: hip bone

• Articulation with vertebral column

• No articulation

• Articulates

• Articulations with axial skeleton

• Very small, through sternoclavicular joint

• Large, through sacroiliac joint

• Aponeurosis

• Palmar aponeurosis has 4 slips making the thumb free for prehension

• Plantar aponeurosis has 5 slips for stability

Joints of Upper Limb

379

Upper limb—Animation Sr. No.

Duration

Question

Topic

BP1

4.25

LAQ-4, SN-15

Introduction to nerve plexus

BP2

1.25

LAQ-4, OLA-6,

Objectives of the video

BP3

2.25

LAQ-4, SN-16

Formation of brachial plexus

BP4

1.25

LAQ-4, OLA-7

Fixation of brachial plexus

BP5

0.50

LAQ-4, OLA-8

Anatomy of brachial plexus

BP6

1.43

LAQ-4, OLA-9

Nomenclature of brachial plexus

BP7

1.15

LAQ-4, OLA-10

Branches of brachial plexus

BP8

2.07

LAQ-4, OLA-11

Branches from cords and details of nerve

BP9

1.09

LAQ-4, OLA-12

Details of each nerve

BP10

3.42

SN-5

Nerve to serratus anterior

BP11

1.38

SN-5

Applied anatomy of nerve to serratus anterior

BP12

3.00

SN-6

Suprascapular nerve

BP13

1.40

SN-7

Nerve to subclavius

BP14

1.20

OLA-13

Branches of lateral cord

BP15

7.04

Musculocutaneous nerve

4 Upper Limb

LAQ-7

Index 3 structures each 320 A band ½ 28 of “I” band 28 of forearm 318 of mammary gland 227 1/3rd of radius 309 1½ fingers 334, 345, 353 1st palmar interossei 338 part of subclavian 227, 286, 359 rib 221, 243, 245–247, 253 thoracic sympathetic ganglion 270 web space 309–310, 351 1st and 2nd lumbrical 272, 325, 338–340 palmar interossei 338 carpo metacarpal joint 375 dorsal interossei muscle 375 layer of sole 170 part of axillary artery 227, 240, 251, 254, 258, 263, 265, 280, 290, 294, 325, 345 tendon of the extensor digitorum longus 164 Thoracic spinal nerves 262 2 adjacent fingers 341 collateral bands 337 common palmar digital nerves 328 digital branches 353 2 heads of flexor carpi ulnaris 347 pronator teres 326 2nd compartment 325 extensor carpi radialis brevis 325 extensor carpi radialis longus 325 2nd layer of sole 170 metatarsal 12,163, 166, 172, 173 part of axillary artery 227–228, 240, 251–252, 254, 258, 263, 280, 294 302, 326, 345 to 6th costal cartilages 240 2nd, 3rd , 4th spaces 343 lumbricals 172, 176, 349 3 borders 3, 223 fingers of the hand 262 fossae 287, 362 interosseous spaces 343 palmar digital branches 327 palmar metacarpal arteries 342–343 perforating arteries 343 roots 262 surfaces 1, 3, 223 thenar muscles 328–329, 334 3rd compartment 325 layer of sole 170 part of axillary artery 254, 258, 280, 294, 302, 325, 345

perforator 118 plantar 171, 173 3rd and 4th lumbricals 176, 351 palmar interossei 338 4 digital branches 341, 342 dorsal interossei 171, 338, 353 hypothenar muscles 353 lumbricals 172, 175, 272, 340, 349 palmar interossei 338, 353 tendons of flexor digitorum profundus 332 tendons of flexor digitorum superficialis 332 4th and 5th metacarpal 338 compartment 175, 325, 372 dorsal interossei 171, 338, 353 layer of sole of foot 170 5th compartment 325, 372 metatarsal 12, 217 osseo-aponeurotic 117, 142 6th and 7th cervical nerve roots 284 6 osseofascial compartments 324 6th costal cartilage 240, 241 7 cervical vertebra 271 8th cervical 296

Abdomen below umbilicus

99 Abdominal wall 89, 99 Abducted arm 242, 260 Abduction of flexed joint 358 index finger 355 shoulder joint 282 Abduction sprains of the subtalar joints 207 Abductor digiti minimi brevis 171, 214, 218, 343, 345 flexor digiti minimi 353 hallucis 170, 172–175, 212, 214 of the thigh 126, 129, 132 pollicis brevis 325, 330, 334, 348, 353 pollicis longus 304–305, 309, 320– 321, 325, 351, 367, 371–372, 375 Aberrant epiphysis 12 Abnormal obturator artery 104 Abrupt 169 Abundant intercellular space 76 Accessory cephalic vein 288 ligaments 25 muscles 31, 201, 208–209, 238, 242, 373 phrenic nerve 238 Accumulation of pus or blood 114 Acetabular labrum 55, 186–187 Acetabulum 133, 186, 188 Acid 75 Acromegaly 334

Acromial process 224 vein 289 Acromio clavicular joint 255, 259, 282 thoracic artery 288 Acromion 239, 255, 355 Acronym 260, 265, 266 Actin filament 28, 68 Action of deltoid muscle 271 interossei 307 lumbrical 307 paradox 30 sphincter pupillae 266 Active contractions 30 lengthening of biceps 30 part of bone 14 resistance 30 Actual arterial anastomosis 32 Acute angulation 290 Adduction of thumb 285, 347 wrist joint 370 Adductor brevis 82, 120, 121, 190 canal 117–119 compartment of the thigh 121 hallucis 159, 170–171, 177 longus 9, 82, 87, 94–95, 103, 109, 117, 120–121, 190 magnus 83, 107, 117, 120–121, 127, 137, 142, 155, 160, 189, 199 pollicis 272, 285, 329 shoulder joint 269 tubercle 83, 117 Adept (proficient) 275 Adherent 10, 13 Adhesion 359 Adipose tissue 41, 46 Adjacent cells 44 nerves 307, 332 Adjoining metacarpal 338 Adrenal gland 47 Adventitial cyst 136–141 layers 72 Aeroplane 237 Afferent lymphatics 75, 105, 139 Aggravate pain 376 Agonists 30 Air conditioning chamber 7 Alignment of distal parts 378 Alimentary 51 Allergens 50 Allergic reactions 50, 51 Alveoli of lung 38 Amphiarthroses 19 Amputation 119, 164 Amyloidosis 336 Analgesia 270 Anastomosing 145, 290, 310 arteries 16, 133 cords 75 Anastomosis 32, 75, 85, 104, 107– 111, 118, 127, 133, 191, 255, 278, 286, 360

381

Anastomosis around elbow joint 360 knee joint. 109, 118, 191 Anastomotic branch 299 channel 342 Anatomical classification of joint 366, 369 neck of humerus 223, 356 snuff box 287, 290, 303–305, 309 Anchor 10, 43, 174 Anconeus 301, 304, 362 Aneurysm of popliteal artery 119, 141, 149 Aneurysmal dilation 271 Anisotropic (A band) 68 Ankle injury 210 joint 26, 140–141, 150, 163, 167, 204–207, 208, 214 sprain 207 Annular ligament 27, 362, 369 Anomalies of breast amastia 231 athelia 232 polythelia 232 supernumerary nipples 232 Anserine bursa 201 Antebrachial fascia 323 Anterior axillary fold 241, 247, 250 line 297 Antero lateral wall 117–119 medially 90 posterior 83 Anterior margin of pubic symphysis 90 Anteroposterior stability 202 Antibodies 51 Antibody complexes 51 Anticipated 290 Antigenic 49 Antigravity action 367 muscles 378 Ape hand 271, 285 median nerve 271 monkey 285 thumb deformity 285, 330 Apex of adductor canal 81, 107 articular disc 368 Apical group of axillary lymph nodes 230, 232 Aponeurosis external oblique muscle 240 of erector spinae 128 Appearance 18, 28, 29, 39, 51, 56, 354 Appendicular skeleton 3, 4 Appositional growth 13 Arabic term 7 Arches of foot 213

Exam-Oriented Anatomy

382 Arcuate artery 162, 164 ligament 152, 198 Area of palm 331 skin 95, 182 Areola 75, 226, 228, 233 Argyrophilic 75 Arteria princeps pollicis 341–342, 348 radialis indicis 341–342, 348 Arch in the foot 341–342 Arterialization 287–290 Arteriolar dilation 270 Arteriovenous anastomosis 32 Artery articular branch to elbow joint 331 chief palpable 163 companion artery of the sciatic nerve 156–160 coronary 32, 33, 180–183, 191, 335 dorsalis pedis 32, 162–163, 184 external iliac 104, 107–111 femoral 107–111, 133, 142–146 inferior gluteal 85, 127, 129, 134, 155, 159 internal iliac 80, 85, 104, 129, 155, 189 lateral circumflex femoral 93, 109, 127, 133, 191 nutrient 11, 13–14, 17, 63, 295, 310, 319, 331 popliteal 107, 110, 119, 121, 135–136, 138, 140–142, 149, 169, 191 tarsal 162, 164 Artery of index finger (branch of radial artery) 341 thumb (branch of radial artery) 341 Articular branch 98, 112–113, 138, 281, 299, 319, 331–332 Articular cartilage 10, 16, 20, 24, 52, 198, 205 Articularis genu 88, 201 Articulating bones 24, 25, 26, 186, 204 surface 20, 23, 27, 185–186, 357, 366, 369 Articulation with axial skeleton 378 vertebral column 378 Arytenoid cartilage 54 Ascending branch of 1st perforating artery 127, 134 lateral circumflex femoral artery 85, 127 medial circumflex femoral artery 85, 127, 157 Asymmetry of the shoulders 284 Atavistic (grandfather) epiphysis 12, 223 Atherosclerosis of popliteal artery 145 Atlanto axial joint 26, 27 occipital joint 27 Atrophy of extensor muscles of thigh 116 Attachment deltoid ligament 212 extensor retinaculum 323, 324 flexor retinaculum 322, 323 ulnar bursa 349 Atypical 23 Auscultation 141, 300 Autonomic nervous system 266 Avascular necrosis 16, 17, 347 Avulsion of the deltoid ligament 207

Axilla 229, 232, 236, 247–250, 256 Axillary abscess 250 artery 227, 240, 243, 248, 250, 253–255, 258, 264, 324, 344 disc 26, 55, 211, 365, 367–370 fascial ‘tent’ 250 fat 249 fold 241, 247–248, 250 line 297 lymph node 230, 232, 249–250, 256, 284 lymphadenopathy 230 nerve 249, 252, 268, 273, 275, 279–282 sheath 243, 246, 248, 271 tail of breast (spence) 249 vein 228, 249, 252–253, 256, 289 vessels 242 Axis of limb 378 movement 153, 172–173, 205 rotation 31 vertebra 27

B

lymphocytes 74 Back door exit 230, 246 Back flow 180 Back of forearm 304, 308 hand 374 knee joint 123 leg 147, 151, 183 talus 12 thigh 99, 146, 160, Backward movement 282–283 Balance of the body 126, 132, Ball and socket 186, 209, 215, 356, 361 Ballet dancers 9 Barbers 290 Barrier 44 Basal lamina (basement membrane) 38 Base of brain 341 digital expansion 336 distal phalanx 337 dorsal digital expansion 336 middle phalanx 337 proximal phalanx of respective finger 338 thumb 374 Basement membrane 37–39, 76 Basilic vein 291, 313 Basophilic 49–51, 54–56, 60–61 Bend of elbow 291, 316 terminal phalanx of thumb 330 Best-developed layer 71 Biaxial 366, 370, 374 Biceps brachialis 268, 296 brachii 242, 248, 249, 295, 298, 326, 360, 364 femoris 82, 124, 127, 141, 149, 155, 159, 189, 200, 224 muscle 356 reflex 295 Biceps brachii 242, 248–249, 293, 295, 325, 360, 364, 367 Bicipital aponeurosis 291, 312, 313 groove 241, 356 Bicondylar joints 27 Bilaminar tendon 241 Bilobed nucleus 51 Bipedal gait of man 168 Bipennate 29, 176, 338–340 Birth canal 267

Blackish 226 Blanket of flexor carpi ulnaris 345 Blockage 32–33, 86, 111, 290, 342, 344 Blood for investigation 313, 315 gas analysis 300, 313, 315 pressure 145, 300, 313 samples 313, 315 spurts 32 Blood supply of compact bone 63 eye ball 33 long bone 14 palm 342, 344 terminal phalanx 347 Blood vessels 5, 10, 11, 25, 50, 65, 101, 227, 257 Bodies of the vertebrae 19 Body of ischium 157 vertebra 4 Boiling 75 Bone cuboid 162, 210 cuneiform 6, 162, 164, 215–216 grafting 85 hip 79–81, 85, 92, 126, 185, 186, 223, 377 marrow examination 85 navicular bone 166, 207, 211, 216 radius 4, 17, 320 sesamoid bone 6–10 tarsal bones 6, 18, 164–165, 207 ulna 4, 15, 17 Bones forming cells 18 pneumatic 7 Bones of upper limb 15, 221 Bony landmarks 83–84 socket 20 structure 7 surfaces 22 Bowing of the shaft 83 Bowman's capsule 38 Bow stringing of muscle 323 Boxer's muscle 235 Brachial artery 291, 292, 297–300, 310, 312–313, 326, 345, 360, 363 plexus 234, 236, 238, 242, 249, 252–254, 257–260, 261, 263, 271, 284, 294, 297, 302, 325, 331, 345, 354, 359 vein 297 Brachio cephalic 71 radialis 288, 301–302, 304–305, 308, 312–313, 360, 362–363 Branch of acromiothoracic artery 288 brachial plexus 288 common carotid 70 deep peroneal 164, 207 external iliac artery 104 facial artery 32 femoral artery 92, 109, 118 internal iliac artery 85, 104 lateral circumflex femoral artery 109, 114, 191 lateral cord 294 posterior cutaneous nerve of thigh 127 radial artery 290, 316, 323, 333, 341, 360, 363 tibial nerves 137,146 Breast tumor 236 Breech delivery 260, 269 Bridegroom’s paralysis 307 Bronchial part of nasal septum 54

Brown adipose tissue 46, 47 fat 41 Bruit on auscultation 141 Buerger's disease 164 Bulging of the calf 168 Bulkiest muscle 128 Bullet 284 Bundles of collagen fibres 10, 173 Bursa complicated bursa 203 gastrocnemius bursa 198 lateral bursa 202 popliteal bursa 198 suprapatellar bursa 198 trochanteric bursa 130, 131, 132 Bursae around knee joint 202 shoulder joint 275 Bursitis 34 Buttress 83

C3 and C4 spinal segment

359 Calcaneocuboid 27, 217 Calcaneum 175, 210 Calcaneus 6 Calcium carbonate CaCO3 61 Calcium chloride 61 Calcium phosphate Ca3 (PO4)2 61 Canal adductor 81, 99, 107–108, 114, 116, 118–119, 137, 146, 180, 184 anal 89 femoral 100–101, 103, 105 hunter’s 117, 118 pudendal 125 Canaliculi 59, 62 Capacity for distension 40 Capillary film 197 network 33, 67 Capitate 6 Capitulum of humerus 366 Capsule of elbow joint 362, 365 hip joint 91, 103, 132, 186 knee joint 121, 135, 138, 142, 191 shoulder joint 276, 280 Capsules of various organs 45 Carcinoma of breast 230 Cardiac catheterization 290 muscle 28, 64–67 Cardiovascular system 32 Carpal bones 3, 18, 318, 320, 322–323, 333, 343 ligament 322, 347 tunnel 322, 330, 333–334, 349 tunnel syndrome 333 Carpentry 374 Carpi radialis brevis 305, 309, 315, 325, 350, 362, 371 longus 31, 301, 303, 305, 308, 325, 371 Carrying angle 364 fibers 169, 302 load on the shoulder 284 Cartilage articular 10, 16, 20, 23, 24, 52, 198, 205 arytenoid 54 corniculate 58 cuneiform 58 elastic 57, 58 fibro 23, 53, 55 hyaline 8, 12, 52–57 white fibro 56, 187, 190

Index Cartilaginous joint 19, 23 plate 23 Cartwheel nucleus 49 Catheterization 99, 290 Cauda equina 114 Caudal root of a brachial plexus 262 Cauliflower ear 58 Causes of carpal tunnel syndrome 333 Causing birth injury 269 Cavitatory joint 24 Cavity of deep palmar arch 345 shoulder joint 357 Cell bodies of neuron 260 membrane 67 Cells adjacent 44 cartilage 53, 54, 56 deepest 39, 40 fat 46, 48, 76 kupffer 48 langerhans 48 luminal surface 39 mast 76 middle 39 mononuclear 59 nerve 43 osteogenic cells 60 ovoid 49, 51 pigment 76 plasma 49, 51, 76 receptor 42 short 39 squamous 39 stellate 50 Central arteries of the cerebrum 33 axillary lymph nodes 256 dislocation 190 dorsal venous arch 290 haversian canal 59, 62 nervous system 48 Centre of head of radius 368 Cephalic vein 287–291 Cerebral palsy 123 Cervical rib 271, 354 vertebra 271 Cervicoaxillary canal 246 Chambers of heart 313, 315 Characteristic 28, 65, 67, 116, 132 Chest wall 235, 239, 250, 283 Chief flexors of hip joint 185 palpable artery 163 Chimpanzee 285 Chondrocytes 54, 57 Chromatin material 51 Chronic cough 106 infection 49 pain 123 Cilia 38, 39, 42 Ciliated 38 Cilium 41 Circle of Willis 32, 341 Circular blackish 226 Circularly 71 Circulation of the limb 111 Circumduction 358 Circumference of head of radius 365 Circumferential lamellae 59, 62 Circumflex fibular branch 192 humeral artery 248, 251, 280, 281, 286, 299, 310, 356, 359 nerve 279 scapular artery 278, 286

Circumpennate 29 Clasps 269 Classification based upon axis 365 depending upon direction of axis 365 of joint 209, 215, 217, 366, 369 of synovial joint 25 Claude bernard 266 Clavicle 4, 223–224, 233, 237, 239– 241, 243, 247, 252, 255, 258, 265, 270, 273, 282, 289, 355, 378 Clavicular fibers of pectoralis major 242, 357 head 221, 240, 290 vein 289 Clavipectoral fascia 223, 227, 241– 242, 244–247, 249–250, 265, 288–289 Claw hand 260, 269–271, 347, 354 Clergymans’ knee 34, 202 Clinical features 116, 284–285, 330, 334 manifestations 266, 268, 270– 271, 310, 374 Clitoris 89, 103, 105 Cloquet lymph node 96, 101–103, 105 lymph vessels 103 lymphatics 96, 101–102, 105 Clubfoot 213–214, 216, 218 Coccyx 90, 126 Collagen fibres 10, 19, 45, 52–54, 56, 61–62, 71, 173 Collapse of the vein 72 Collateral aspects 336 bands 337 branches 147, 157, 304, 361 circulation 32, 86, 111, 134 ligaments 83, 162, 196, 199, 201, 205, 210, 298, 332 Colle's fracture 373, 374 Colour zone 59 Columnar 39, 40 Combination of movements 209, 358 Common digital nerve 328, 331 flexors of forearm 362 iliac vessels 121 interosseous 312 Communicating branches to anterior 319 posterior carpal arch 319 superficial palmar arch 319 Compact bone 16 Companion artery of the sciatic nerve 159 Comparative anatomy 93 Compartment leg 147, 150–151, 155, 160, 162, 168, 177, 206 lower part of forearm 304 of the arm 294, 298, 302 thigh 88, 94,121, 155, 160 upper limb 262 Compensate 32, 72 Complete clawhand 270 Complex joint 26, 190 Complicated bursa 203 Compound epithelium 42 Compression of brachial artery 300 median nerve 330, 331 radial nerve 307 volar carpal ligament 347 Compressive forces 83 Concave surfaces 53 Concavities of calcaneus 218

383 Concavity of the arch 218 Concentric lamellae 59, 62 layer 71 Condensation 357 Conduction 66, 355 Condylar 27, 190, 194, 198 Condyles of tibial 90, 191, 195, 197 Congenital deformity of the foot 213, 216, 218 dislocation 190 high scapula 271 syphilis 17 Conjunct 201 Connective tissue fasciae 72 fibres 25, 64, 71 resistance 30 Conoid tubercle 223 Conspicuous 292 Constipation 106 Contact sports (wrestlers) 58 Continuation of axillary artery 297, 298 main nerve 305 posterior cord 302 profunda artery 310 ulnar artery 341 Contour of deltoid 282 shoulder region 275 Contractile unit of the muscle 28, 67 Contraction 31, 66, 68, 155, 168, 206, 215, 218, 243, 321 Contraction muscle 30 Convex edges 72 osseous surfaces 53 Convexity archm 343 Coraco acromial arch 355, 358 acromial ligament 223, 275, 355, 357 brachialis 223–224, 242, 248– 249, 252, 257, 268, 295–296, 298–299, 302, 368 clavicular ligament 223–224, 283 humeral ligament 223, 357 Coracoid process of scapula 12, 224, 275, 291 Cord lateral 249, 252–253, 262–263, 265–266, 268–269, 272 medial 249, 252–254, 257, 262– 263, 272 posterior 249, 252–254, 260, 263, 268–269 Cords of brachial plexus 240, 242, 249, 254, 262–263, 272 Cornea 40 Corniculate cartilage 58 Coronal suture 21 Coronary arteries 32–33, 183 artery disease 335 ligament 192, 198 Coronoid 362–363 Cortex 74–75 Cortical branch of cerebral arteries 32 Costa cervicalis 271 Costal cartilage 55, 241 surface 234 Costo chondral junction 239, 243 coracoid ligament 221, 243 Counting of fingers 330

Course of posterior interosseous nerve 304 Cover of brachioradialis 304 deltoid 274 gluteus maximus 127, 188 Cranial cavity 21 nerves 266 Crazy bone (funny bone) 355 Cremaster muscle 79 Crescent 106, 195 Crest iliac 83–85, 90–91 intertrochanteric 186 pubic 90 Cribriform fascia 92–93, 95, 180, 182 Cricoid 54 Cross section 117, 195, 357 striations 64, 65 Cruciate anastomosis 133 ligament 153, 192–194, 197, 201–202 Crutch palsy 307, 309 paralysis 307 Cubical 5 Cubital articulation 361 fossa 137, 287 292, 300, 302, 304–305, 312, 313–315, 325, 328, 331, 362 tunnel syndrome 347 vein 289–292, 313 Cuboid bone 162 Cuneiform 6 bones 162, 164, 215 cartilage 58 Curvature 83 Curve posterior 280 round 280 Cushion 46, 48, 195 Cusps 72 Cutaneous anaesthesia 270 branch 98, 112, 159, 164–165, 174, 266, 296, 301, 326 lymphatics 231 nerve of forearm 288, 295–296, 305 nerves 88, 147, 177–178 supply of dorsum of hand 335 supply of palm of hand 334 vein of thigh 182 Cytoplasm 47, 49–51, 59–62 Cytoplasmic 59–62 Cytoskeleton 43

Dark nucleus 48 staining band 28 zone 68 Dead space 105 Deep branch of the superior gluteal artery 132 cervical fascia 343, 348 external pudendal vein 182 external pudendal artery 92– 93, 94–100, 102, 110, 180– 183 fascia 183, 225–226, 243, 247, 250, 253, 281, 291, 295, 297, 313, 318, 323, 328, 332 fascia of lower limb 88, 89 fascial 253 flexor muscles of forearm 331

384 flexor tendons of digits 327, 343 inguinal lymph nodes 93, 99, 105 intramuscular injection 132, 160 lamina 91 layer 249 lymph vessels 118 lymphatics of the lower limb 105 muscles of calf 149 nodes 139 palmar arch 316, 320, 341, 342– 344, 345, 353, 377 parts of the leg and foot 139 pectoralis minor 240, 249–251, 253 perineal pouch 81 Deep branch of radial nerve 315 superior gluteal artery 132 transverse cervical artery 286 ulnar nerve 339, 341, 345, 348, 353 Deeper structures 90, 93, 175, 228 vascular layer 10 Deepest cells 39 Definition of brachial plexus 261 Deformed 374 Deformity of position of the hand 270 scapula 271, 282 the foot 211, 213, 216, 218 Degenerated tendon 235 Degeneration 11, 57, 376 Deltoid branch of acromiothoracic artery 288 ligament 205, 207, 208, 211, 212 region 277 tuberosity 277 Deep head of flexor pollicis brevis 348, 354 pronator teres 326 Deep layer formed by clavipectoral fascia 247 pectoralis minor 247 subclavius 247 suspensory ligament of axilla 247 Deep muscles clavipectoral fascia 227 pectoralis minor 227 subclavius 227 suspensory ligament of axilla 227 Deep muscles of calf 149 forearm 327 thigh 110 Deltopectoral groove 288 Dense bundle of collagen fibers 61 collagen bundles 45 connective tissue 45, 75 irregular connective tissue 45 matrix 54 regular connective tissue 45 Densely packed lymphocytes 75 stained 65 Denticulate 20–22 Depressed triangular 321 Depression of acromioclavicular joint 282 sternoclavicular joint 282 Dermis of skin 45 Descending artery 298, 361, 363 Descending branch of inferior gluteal artery 134 superior gluteal artery 85

Exam-Oriented Anatomy Descending genicular 110, 118, 139 Descent of scapula 271 Desmos band 22 Desmosome 67 Destroying cells 10 Detached 168, 271 Diabetes mellitus 116, 234 Diagnosis 106, 232 Dialysis machine 290 Diameter 4, 7, 16, 68–71, 75, 104 Diaphragm 359 Diaphysis 3, 9, 13, 17, 23, 62 Diarthrosis 354, 361, 370, 374 Diffusion of ions 66 nutrients 53 Digital branch of superficial palmar arch 343 ulnar nerve 331 Digital arteries 162, 342, 347 branches of median nerve 342 nerves 335, 341 tendons of lumbricals 335 vessels 173, 335, 341 Dimension 4, 338 Diminishes the friction 8 Dinner fork deformity 373 Direct trauma 156, 169, 267 Direction axis 25, 211, 365 Disability 53, 268, 285 Discrete internal elastic lamina 72 Dislocated head of humerus 255 Dislocation of hip joint 185 shoulder 282, 355 Dislodged thrombus 169 Displaced hand 374 laterally 367 medially 367 Disproportionate articular surfaces 359 Distal 2/3rd of forearm 316 border of flexor retinaculum 329 carpal bones 325 end of 1st metacarpal 12 foot 378 fragment 374 palmar crease 341 part of tibia 204 phalanx of the little finger 332 radioulnar 370 row of carpal tunnel 322 surface of trapezium 375 wings 337 Distinct ridge 94 Distorted injury 58 Distributing artery 69 Distribution of radial nerve 308 ulnar nerve 345 Division of axillary nerve 280, 281 obturator nerve 116–118, 135, 138–139, 197 upper trunk 267 Domains 43 Dome of axilla 246 Donors 290 Dorsal carpal arch 373 Dorsal digital expansion 336–338, 340 veins of the thumb 288 vessels and nerves 341

Dorsiflexed at ankle joint 140, 214 Dorsiflexion 151, 206, 208–210, 334 Dorsum of hand and finger 302 proximal phalanx 336 Downward direction 277 Drainage area 184 Drains lateral side of arm 287 forearm 287 hand 287 shoulder 287 Drooping of shoulder 287 upper eyelid 266 Droplets 46 Dry surface 40 Dupuytren’s contracture 335, 336 Dural venous sinuses 72, 169 Dynamic stability 31

Eccentric nucleus 48, 51 Edema premenstrual 334 Edge of anterior axillary fold 250 articulating surfaces 357 cervical rib 271 Efferent ductules 38, 42 lymphatics 88–89, 96, 101, 105 Effusion of joint 363 Elastic arches 215 artery 70, 71 cartilage 57, 58 connective tissue 20 fibers 57, 71 recoil of the vein 72 Elasticity 75 Elastin protein 75 Elbow at the wrist 354 extension 307 joint 137, 295, 299, 304, 313, 320, 328, 333–334, 345, 349, 360, 361–363 pain 376 wrist joint 316, 320, 328 Electron microscope 57 Elements of hip bone 126 Elevation of lower eyelid 266 sternoclavicular joint 282 Ellipsoid joint 27 Elongated shaft 18 Emboli 271 Embryo 289 external jugular vein 289 front of the clavicle 289 injured in fracture of clavicle 289 Embryonic limb buds 377 Eminence 187, 285, 333, 345, 348, 353, 354–355, 375 Empty compartment 104 End arteries 33 End of clavicle 282–283 dorsal venous arch 180, 287 Endocrine organ 46 Endomysium 65, 66 Endosteal 16, 62 Endothelial lining 73 Endothelium of blood vessel 38 Enlargement of bursa 34 Entrapment of ulnar nerve 347 Enzymes 50 Eosinophilic 57, 61 Eosinophils 51 Epicondyle 199, 291, 302, 305, 314, 345, 347, 350, 355, 360–363, 376, 377

Epiphyseal artery 13, 16, 347 cartilage 13, 16 end of diaphysis 13 line 9, 83 plate of cartilage 13 separation 16 Epiphyses of long bones 10 Epiphysis of long bone 23 Epithelial lining 231 Epithelium compound 42 cuboidal 229 lining 38 multilayered 39 pseudostratified 39 simple columnar 38, 39 simple squamous 37, 70 stratified squamous 39, 40 stratified squamous keratinized 40 stratified squamous nonkeratinized 40 transitional 40, 41 Erb’s palsy 260, 267–269 paralysis 260, 267–268, 295 point 260, 267 Erect posture 168 Erector spinae 84, 85, 128 Erosion 62 Erythropoiesis 13 Escape of synovial fluid 34 Esophagu 40, 42 Ethmoid 7 Etiology 333 Eustachian tube (medial part) 58 Eversion of foot 151, 207 Eversion 140, 209, 210–211, 368 sprains 211 Evolution 7, 12, 223 Excessive pulling 267 Exposing 270 Exposure of radial nerve 308 Extended elbow 295, 364, 368 knee 126, 129, 137, 156 position 269 Extension interphalangeal joint 339, 341 Extensor carpi radialis brevis muscle 309, 315, 350, 362, 376 carpi radialis longus 31, 301, 302, 305, 307, 362, 373 carpi ulnaris 31, 305, 310, 350, 362, 372–373 digiti minimi 305, 310, 350, 373 digitorum 29, 31, 150, 161–162, 206, 208, 305, 309, 350, 362, 372–373 fingers 270 hallucis brevis 164 hallucis longus 150–151, 161– 162, 164, 206, 208 indices 305, 309 indicis 350, 367, 372, 373 interphalangeal joints 341 metacarpophalangeal joints 337 mmuscles of forearm 287, 376 pollicis brevis 302, 305, 309, 318, 321, 351, 367, 371, 375, 376 pollicis longus 302, 305, 309, 318, 321, 350, 367, 371, 373 retinaculum 163, 288, 323–324, 371

Index Extensor expansion index finger 332 little finger 350 middle finger 337 ring finger 350 External acoustic meatus (lateral part) 57 ear 32, 57, 58 elastic lamina 71, 73 iliac group of lymph nodes 105 intercostal muscles 239 oblique 84, 227, 240–241 occipital protuberance 238 surface 9 Extra capsular 14 cellular link protein 43 cellular matrix 43 Extremely painful 11 Extremities of long bones 10 Extrinsic 120, 177, 355

Fabella (little bean)

9 Failure of descent of scapula 271 Falciform margin 92 Fallopian tube 38, 42 Fascia cribriform 92– 93, 95, 180, 182 deep 183–184, 225–226, 243, 247, 250, 252–253, 281, 291, 295, 297–298, 313, 318, 323–324, 328 iliaca 101 iliacus 95, 101 lata 79, 84, 90–91, 93, 102, 117, 121, 132, 137, 180, 184 superficial 76, 94, 102, 114, 137, 164, 225, 227, 241, 247, 252–253, 298, 317–318 tensor fascia lata 90, 190, 201– 202 thick fascia 91 thoracolumbar fascia 84 transversalis 79, 84, 101 Fascia covering flexor 323 gluteus medius 128 interossei 349 Fascial floor of lower part 237 Fascicles 64 Fasciculate 128 Fat cells 46, 48, 76 Fatal 99, 169 Fate of periosteum 11 Fatty connective tissue 103 stroma 226 Feathers 29 Femoral artery 32, 85, 92–96, 98–99, 101– 103, 107–111 branch of the genitofemoral nerve 87, 95, 98 canal 96, 100–105 condyles 137 hernia 99–100, 103–105 nerve 96, 98, 103, 112–116 pulse 116 ring 99–100, 103–104 sheath 92, 95, 98–99, 101–102, 104 tendon of popliteus 192 triangle 93, 96, 94–100 vein 96, 98–99, 101–103, 105 vessels 99, 101, 103 Femur 4, 11–15, 17–18, 81, 83, 109, 118, 121, 125, 132, 134–135, 141, 155, 186, 191, 193–194, 203–205, 378 Fenestrated elastic fibers 71

Fibers of connective tissue 64 deltoid 358 extensor carpi radialis brevis muscle 363 extensor 363 serratus anterior 236, 282, 283 sharpey 10 Fibro blast 76, 45, 47 cartilaginous articular disc 365 cytes 47, 52 cartilage 23, 53, 55–56, 187, 190, 357 osseous ring 367 osseous tunnel 333 Fibrofatty stroma 226, 231 tissue 96, 101–102, 105, 124, 229 Fibrosis 335 Fibrous capsule of the joints 9 Fibula 4, 11, 166–168, 204–205, 207, 378 Fibular collateral ligament 202 malleolus 207, 208 Filaments actin 28, 68 myosin 28, 68 Finger cleft 343 Fingers (C8) 269 Firm 55, 56, 235 First carpo metacarpal joint 374 condrosternal joint 23 dorsal interossei 375 dorsal interosseous 357 metacarpal 375 web space posteriorly 349 Fixators 31 Fixed vein 313, 315 Flat foot 213, 216, 218 nucleus 47 Flattened cells 229 tendons 275, 335 Flattening of the thenar eminence 285 Fleshy fibers 28–29 Flexed knee 137, 167, 193, 202 Flexibility 23, 58, 72, 75 Flexible 57 Flexion at metacarpophalangeal joint 341 elbow 30–31, 269, 367 of digit 31 of elbow joint 30, 269, 295 of interphalangeal joints 270, 347, 354 of metacarpophalangeal joint 307, 339, 343, 355 of thumb 30 of wrist joint 30, 31, 307 Flexor accessories 171 carpi radialis 31, 312, 315, 317– 318, 323, 327–328, 330–333, 360, 362, 371, 375 carpi ulnaris 9, 30, 272, 318, 320, 331–332, 345, 349, 362, 371, 373 compartment of arm 294 digiti minimi brevis 170 digitorum accessories 171 digitorum brevis 170–172, 175 digitorum longus 161, 169–170, 176–177, 206, 208, 213, 215, 218 digitorum profundus 272, 312, 318, 320, 323, 328, 331–333,

385 340, 342, 345, 347, 354, 360, 366, 371, 373–374 digitorum superficialis 31, 168, 304, 312, 315, 317–318, 323, 327–328, 330–333, 342, 347, 360, 362, 371, 374 muscles of the forearm 331 of elbow joint 293 retinaculum 147, 149, 175, 323– 324, 327–329, 332–335, 345, 352 Flooded 14 Floor of base of 1st metacarpal bone 321 carpal tunnel 349 Flying animals 242 Foetus 261 Follicles 42, 74–75, 231 Foot drop 151, 160 Forearm supinated 364 Formation of alveoli 228 ankle joint 202 arch 213 brachial plexus 257–258, 263 cephalic vein 288 hip joint 185–186 joint 12 ring 27 thrombosis 141 Forward rotation of the scapula 283 Fractional relaxation 30 Fracture of ankle joint 207 bone 9 clavicle 243, 267, 289 coronoid process 363 distal part of radius 374 fibula 207 medial malleolus of tibia 207 middle 1/3rd of the shaft of humerus 279, 309 proximal 1/3rd of radius 309 scaphoid 322 shaft of humerus 307, 309 surgical neck of humerus 275, 277, 282 tibia 207 upper end of humerus 282 Freedom 34, 103 Freely movable 20 Frequency 260 Frequently dislocating joint 359 Friction 8, 34, 53, 237 Front of arm 295, 331 elbow joint 313 lateral epicondyle of the humerus 360, 363 lower part of arm 301 median nerve 292 thigh 94, 98, 101, 112 Frontal 7 Frozen shoulder 359 Functional contractile unit of the muscle 28, 67 syncytium 66 unit of the sarcomere 28, 67 Funny bone 347, 355 sensations 347 Fusion of fascia iliaca 101 transversalis 101

Gallbladder 38 Gangrene of toes 164 Gap junctions 44, 66 Gastrocnemius bursa 198

Gastrointestinal tract 38 Gelatin 75 Gemelli 126, 188, 190 Gender 18, 46, 105, 334, 364 Genicular branch of femoral artery 191 popliteal artery 191 posterior division of obturator nerve 118, 135, 138–139, 197 Genicular branches to the knee joint 138 Genitofemoral nerve 87, 95, 98, 101–103, 108 Germ layer ectoderm 231 mesoderm 231 Gibbons 285 Girdle 185, 190, 259, 264, 282–283, 357, 387 Girth 62 Gland adrenal 47 moderate sized ducts of salivary 42 Glandular part 226 tissue 228, 229 Glans penis 103 Glenohumeral joint 356, 359 ligament 34, 357 Glenoid cavity 275, 356–357, 359 labrum 55, 357 process of scapula 293 Gliding movements 209 Glistening tendon of latissimus dorsi 302 Global brachial plexus birth palsy 260 Glomeruli 33 Gluteal line 81, 128, 132 muscles 127–128, 160 region 80, 90, 98– 99, 125, 128– 129, 132, 157–158, 160 surface of ilium 132 tuberosity 82, 128 Gluteus maximus 84, 90–91, 124–129, 130–131, 156–157, 188– 190, 202 medius 126–128, 131–133, 190 minimus 127, 132–133, 188, 190 Glycogen 67 Gomphosis 19–22 Gonococcal infection 25 Gorilla 285 Gracilis 120–121, 137, 141, 200, 203 Gradual 30 Graft surgically 11 Grasping and skilled movement 378 Grave yard of ulnar nerve 354 Gravity 30, 72, 91, 132, 206, 280, 283, 365 Great saphenous vein 88–89, 92, 96, 101–102, 114, 118, 180–183, 179, 184, 289 vessels 47, 313 Greater part of gluteus maximus 91 sciatic foramen 80–81, 156–157 sciatic notch 79–81 trochanter of femur 18, 126, 132 tubercle 275 tubercle of humerus 18, 282 Grey matter 260 Grip of the hand 335 Gripping 353

Exam-Oriented Anatomy

386 Groove humerus 241 Ground substance 45, 54, 56, 61 Groups of muscle 31, 318 Growing end of long bone 17 Growth of brain 21 Gunshot wounds 116, 267 Guyon’s canal 347

H band

68 Haematogenous spread of infection 14 Haemorrhage 72, 110, 298 Half of deltoid 280 Hamate 6, 320, 323, 333, 345 Hamstring muscles 124, 155–157, 189, 200 Hand adducted 330 ape-like 285 Haversian pad of fat 192 system 8, 16, 59–60, 62–63 Head of 1st, 2nd and 3rd metatarsals 215 4th and 5th metatarsal 217 femur 13, 85, 98, 110, 121, 133, 185–188 fibula 90, 159, 162, 167–168, 199 gastrocnemius 138, 145, 147 humerus 12, 255–276, 355, 359 metacarpal 335, 336 radius 27, 211, 361, 365–366, 368–369 rectus femoris 85,126, 133 talus 212, 214–215 triceps 275, 277–278, 280–281, 298, 301–302, 305, 308, 310–311, 345, 352, 358–359 ulna 365 Healing capacity 53 Heart function 66 wall 64 Heavy bleeding 238 Heel 147, 149, 184, 210–211, 213, 216, 218 Henson’s disease 347 Hepatic nodes 231 Herniorrhaphy 106 Heterophilic binding 43 High arched foot 174 Higher magnification 64 Highly dependent 46 Hilton’s law 113, 185, 188, 280, 282 Hinge 26, 153, 190, 204, 361, 366 Hip bone 79–81, 85, 92, 126, 185– 186, 221, 378 Hip joint 25, 26, 53, 79, 91, 98, 103, 112–114, 121, 123, 126, 128–130, 132–133, 155, 157, 160, 185, 186–190 Histamine 50 Hollow organs 64 Homogeneous 55 Homologous movements 368 vein 287 Homophilic binding 43 Hook of hamate 322–323, 345 Horizontal plane 235 Hormonal control 228 Horner’s syndrome 260, 266, 270 Horns 196, 260 House painting 376 Housemaid’s knee 34, 202 Howship’s lacunae 59 Human character 168 Humeral artery 248, 251, 280–281, 286, 299, 310, 356, 359

Humero radial joint 361 ulnar joint 361 Humidity 7 Hunterian perforator 118 Hunter’s canal 118 Hyaline cartilage 8, 12, 23–24, 52– 57 Hyaluronic acid 25, 61 Hyperextension at metacarpo phalangeal joint 270, 347, 354 Hypohydrosis 264 Hypothenar eminence 345, 353–354 muscles 323, 332, 353 spaces 348 surface 347

ICAMs (intercellular

cell adhesion molecules) 43 Iliac crest 83–85, 90–91, 128, 132, 256 Iliacus 87, 95, 101, 111–112, 114, 185, 189 Ilio femoral ligament 79, 85, 187 tibial tract 90–92, 128, 130, 191, 202 Ilium 79, 83, 126, 132, 133 Ill defined 92 Imaginary line 314 Immature bone 14 Immobilized patients 125 Immovable 20, 23 Immune mechanism 49 Impulse to relax 30 Impure blood 290 Incision 119, 141, 230, 347, 349 Inclined posteriorly 373 Incongruent 203 Incudomalleolar 26 Incudostapedial 26 Indispensable 202 Indistinguishable 70 Indwelling cannula 290 Infant’s head 267 neck 267 Infection of bone 13 pulp space 347 skin 99 sole 174 Inferior angle 147, 234, 236 angle of scapula 237, 283, 357 band 357, 362 belly of omohyoid 270 border of pectoralis minor 256 border of the piriformis 156 capsule of shoulder joint 280 dislocation 359 gemellus muscle 81, 124 glenohumeral ligament 34 gluteal artery 85, 127, 129, 134, 155, 159 gluteal nerve 125, 127, 129, 157 gluteal vessels 80, 157 lateral genicular 150 margin of the tibial condyles 90 radioulnar joint 26, 211, 293, 351, 364–366, 368, 369 side 356 surface of clavicle 243 surface of lower end of radius 366, 369 tibiofibular joint 20, 22, 148, 205 ulnar collateral artery 301, 361– 362 venae cavae 71

Inferiorly long head of triceps 358 Inferolateral to the pubic tubercle 100 Inferomedial quadrant 227 Inflamed joint capsule of the glenohumeral joint 359 Inflammation of bursa 34, 125, 363, 376 periosteum 11, 376 tissues 377 ulnar side of palmar aponeurosis 335 Influence of gravity 132, 283 Infraclavicular nodes 246, 288 part 258, 263, 270 Infrapatellar bursa of knee joint 34 Infraspinatus 31, 237, 238, 259, 268–269, 275–276, 278, 286, 352, 356, 358–359 Inguinal ligament 79, 83, 85, 87, 88–90, 94, 98, 100, 102–104, 107, 109, 110, 114, 117 region 231 Inhibited 30 Initial abductor of shoulder joint 269 Injected 116, 377 Injection in radial groove 309 Injuries 56, 156, 285 Injury dashboard 190 lathi 151 Injury of brachial plexus 260 lower roots 269 spinal accessory nerve 286 T1 nerve 270 upper trunk 260, 267 Inner chondrogenic 57 circumferential 59, 62 edge 255 medulla 75 side of palm 349 sloping area 84 surface of capsule 197, 356, 362 Innermost coat 70 Innervations 330 Inorganic element 61 Insertion palmar aponeurosis 335 tendon of lumbricals 337 Inspired air 7, 55 Instances 31 Insulation under the skin 46 Insulator 48 Intact ulnar nerve supply 355 Integrins 43 Integrity 47, 195, 218, 293, 306, 355 Intensification of sound 7 Inter calated disc 65, 67 cellular substance 37, 54 condylar ridge 191 Intercostal arteries 228, 234, 236 muscles 234, 239, 248, 250, 253 nerve 228 space 226–227, 242–243 vein 228 Intercostobrachial nerves 249 Intercondylar area of tibia 198 Intermediate cuneiform bones 6, 164 cutaneous nerve of thigh 96, 112–113 nodes 139 palmar septum 349

Intermittent attacks of pain 334 claudication 111 Internal elastic lamina 69–70, 72–73 fixation 374 iliac artery 80–81, 85, 104, 129, 134, 155, 157, 189 iliac vein 81 iliac vessels 80, 121 mammary artery 233, 234 mammary lymph nodes 232 oblique 84 pudendal 80, 85, 127 thoracic (mammary) artery 227 thoracic vein 227 venous plexus 228 Internus 127 Interossei 338–339 dorsal 29, 170–171, 332, 337– 339, 346, 350, 353–354 palmar 29, 171, 332, 337–339, 346, 350, 353–354 Interphalangeal joints 270, 307, 337, 339, 341, 343, 347, 354 of hand 53 Intersegmental tie or staples 218 Interstitial growth 13 lamellae 59, 62 matrix 54 Interterritorial matrix 53 Intertrochanteric crest 186 Intertrochanteric line 79, 186, 187 Intertubercular sulcus 248, 255, 275 vening fascia 239 Intestinal lipoproteins 46 mesentery 46 Intoxicated 307 Intra abdominal pressure 106 articular disc 26 articular structures of knee joint 192 cellular binding protein 43 muscular injection 132, 160, 288 tendon of long head of biceps 358 uterine life 6, 231 venous injection 290–291, 313 Intracapsular 14, 85, 152, 187, 352, 358–359 metaphysis 14 part of neck of femur 85 stabilize 352, 359 Intrinsic muscles of hand 345, 347, 353 Introduction of cardiac catheter 313, 315 Inversion 151, 209–210, 211, 216, 368 of foot 167, 207 sprain 210 Inverters of foot 213 Involuntary muscles 64 Involvement of proximal and middle phalanx 335 Ions 66 Irregular intervals 65 Irreversible deltoid palsy 275 Irritation of diaphragm 359 Ischial fibers of adductor magnus muscle 83, 124, 127, 155, 157, 160, 189, 199 spine 79, 80, 85 tuberosity 34 , 81, 90, 124–125, 129–131, 155–157

Index Ischio femoral ligaments 131–132, 187 pubic ramus 90 Ischium 124, 126, 157, 223 Iso metric 30 tonic 30 tropic (I band) 68

Jejunum 38, 42 Jerk 116, 151, 295 Joint capsule 7, 14, 16, 199, 359 cavity 25, 26, 34, 195 elbow 26, 30, 137, 293, 295, 299, 304, 313, 320, 328, 331–332, 345, 347, 360, 361–363, 365–367 hip 26, 53, 79, 91, 98, 103, 113– 114, 121, 123, 126, 128–129, 132–133, 155, 157, 160, 185–186 inferior radioulnar 351, 364– 366, 369 intercarpal 351, 370 interphalangeal 307, 337, 339, 354 knee 9, 18, 25–27, 34, 53, 55, 91, 98, 109, 112–114, 116, 121, 123, 135, 137–138, 140–142, 147 metacarpophalangeal 307, 336–337, 339, 341, 347, 354, 374 of skull 21 radioulnar 364, 369 shoulder 295, 299, 352, 355, 356–359 superior radioulnar 295, 360, 362, 364–365, 369 superior ulnar collateral 297 synovial 356, 361, 366, 370, 374 temporomandibular 26–27, 53, 55 wrist 307, 309, 316, 319–320, 331, 333, 347, 351, 360, 366, 369–374 Junction of neck and thorax 257, 260 Junctional complexes 43, 65 Juxtaepiphyseal artery 14 Klumpke’s paralysis

260, 269– 270 Knee jerk 116 joint 151–153, 155, 159, 190–194, 196–197, 199–204, 208 Knife fight 284 Krukenberg’s tumor 231, 234 Kupffer cells 48

Labial artery

32 Labium majus in female 110 Lactiferous duct 226, 230 sinus 226 Lacunae 53, 59, 61–62 Lambdoid suture 20, 21 Lamellae 59–60, 62–63 Lamina basal lamina (basement membrane) 38 discrete internal elastic lamina 72 external elastic lamina 71, 73 internal elastic lamina 69–70, 72–73 splendens 52 subchondral osseous lamina 53 Laminae 91 Langerhans cells 48

Large arteries of head and neck 71 lumina 229 nutrient branch to the femur 109 protein 28 spaces 75 Larger bony areas 378 bronchi 39 ducts 231 terminal branch of brachial artery 316 ulnar artery 312 Largest branch of the whole brachial plexus 302 joint 25 tributary of axillary vein 289 vein of the upper limb 290 Larynx 54 Lateral 3 digital branches 341–342 aspect of the forearm 295 axillary lymph nodes 256 common digital nerve 328, 331 cord of brachial plexus 252 cuneiform 6 cutaneous nerve of arm 281– 282, 305 cutaneous nerve of forearm 288, 295–296, 313, 315 deep slip 322 end of dorsal venous arch 287 epicondyle of humerus 362 epicondylitis 377 flange of trochlea 364 flexor digitorum superficialis 318 half of breast 256 head of gastrocnemius 135, 137, 143, 146, 161, 202 head of triceps 301, 305, 308, 310–311 incision 119, 141, 228, 345, 347 intramuscular septum 310 ligament 191, 205, 208, 375 lip of bicipital groove 241 longitudinal arch 174, 214, 217–218 longitudinal strip 261 lower border 240 margin of biceps tendon 315 pectoral nerve 240, 242, 246, 249, 253, 259, 265–266, 359 quadrant of the mammary gland 228 side of the elbow joint 365 strip 261 Lateral border of acromion process of scapula 273 dorsal digital expansion 340 foot 147, 184, 210 pectoralis major 227, 288 pronator teres 312–313, 314 scapula 278 Lateral branches of anterior rami 261 thyrocervical trunk 270 ventral rami 261 Laterally abductor pollicis longus 375 biceps 155, 223 crest of the trapezium 322 extensor pollicis brevis 351 median and medially the ulnar nerve 317 Laterally tendon of abductor pollicis longus 320, 321

387 extensor pollicis brevis 320, 321 tubercle of the scaphoid 322 Lathi injury 151 Latissimus dorsi 84, 242, 248–249, 260, 265, 268–269, 302, 352, 357, 359 Law of Sherrington 30 Lawn tennis 378 Laxity 356 Laxity of capsule 360 Layer adventitial 72 best-developed 71 concentric 71 subendothelial 70 vascular 10 Layer of hyaline cartilage 24 Layers of fascia 250 sole 175 Leg, sole and external genitalia 99 Length of biceps 30 cell 39 fibres 30 muscle 30 muscle fibre 30 myocyte 66 Lengthening 30 Leprosy 347 Leptin 46 Lesion axillary nerve 277, 282 musculocutaneous nerve 295 nerve 295 radial nerve 309 saphenous nerve 183 superficial radial nerve 309 Less ground substance 45 Leucocytes 43, 51 Levator scapulae 239, 283 Level of amputation of leg 164 lateral epicondyle 302, 305 Lever 3, 213 Liberation of malignant cells 250 Lifting a glass 376 Ligament arcuate 152, 198 arcuate popliteal 152 attachment to deltoid 212 avulsion of the deltoid 207 calcaneofibular 207–208, 210 capsular 79, 164, 375 collateral 162, 199, 205, 210, 376 coronary 192, 198 cruciate 153, 192–194, 202 deep tibio talar ligament 208 deltoid 205, 207–208, 211–212 fibular collateral 202 iliofemoral 79, 85, 187 inguinal 79, 83, 85, 87–90, 94, 98, 100, 102–104, 107, 109– 110, 114, 117 ischiofemoral 131–132, 187 lacunar 79, 87, 104, 106 long plantar 214, 218 medial margin of spring ligament 207 meniscofemoral 192, 196–197 oblique popliteal 135, 138, 191, 197 posterior cruciate 193–194, 195, 197 talofibular 208, 210 pubofemoral 121, 187 sacrospinous 85, 131 sacrotuberous 81, 85, 90, 124, 128, 131 short plantar 214, 218 spring 207, 211 superficial tibiotalar 208

tibial collateral 83, 196, 203 tibiocalcanean 208 tibionavicular 207–208 tibiotalar 208 transverse acetabular 186–188 transverse metacarpal 336, 338 Ligament anterior cruciate 193–194, 201 talofibular 207–208, 210 Ligament of ankle joint 164, 205 dorsal radiocarpal 370 head of the femur 121, 187, 188 hip joint 79 palmar radiocarpal 370 palmar ulnocarpal 370 radial collateral 370 shoulder joint 275 ulnar collateral 370 Lips 32, 82, 173, 175, 201, 245, 331, 335, 378 Ligamentum flava 75 nuchae 239 Light staining band 28 zone 68 Limb buds 261, 377 of the body 30 Limbus borders 22 Line of gravity 206 Lines of the cannula 290 Linea aspera of femur 82, 118 Lining epithelium 38 Link joint 372 Lip 32, 40, 82, 90, 239, 241, 273, 322– 323 Lipid storage 46 Lipoma 141 Little fingers 73, 99, 104, 156, 285, 305, 332, 336, 347, 350, 354–355, 368, 371 Liver 46, 48, 234 Lobes 50, 226 Local circulation 8 Location axillary lymph nodes 256 Locking 201, 203–204 Locomotion 210–211, 377 Long and medial heads of triceps 304 axis of the body 3 bone 3–5, 9–15, 17–18, 23, 63, 223 broad surface 29 distance runners 9 flexors 270 muscles of shoulder 352, 359 standing case of paralysis 270 Long head of biceps 124, 155, 157, 160, 248, 275, 352, 356, 358–359 biceps brachii 248 biceps femoris 124 triceps 275, 277–278, 280–281, 298, 301–302, 352, 358–359 Longitudinal arch 213, 218 axis 172–173 ligament blends 11 muscle iliac 71 ridges 324 section 65, 66 Longus and brevis 162, 206, 211, 373 Loop of Henle 38 Loose areolar connective tissue 76 tissue 75 Loss of abduction of shoulder joint 282 biceps tendon reflex 295 ciliospinal reflex 270

388 extension of wrist 309 flexion of forearm and wrist 272 sensation of radial side of dorsum of hand 309 strong flexion 295 Low cuboidal 230 lesion 354 nodes 232 Lower limb limit of the flank 84 lip of crest of spine of scapula 273 Lower lateral cutaneous nerve of arm 305 zpart of skin of deltoid 279 Lower margin of radial notch of ulna 365 ulnar notch of the radius 365 Lubrication 25 Lumen 39, 72–73, 183, 230 Lumina 38–39, 69, 71, 229 Luminal surface of the cells 39 Lump 114, 169, 231 Lunate 5, 366, 369–370 Lymph node 48, 74–75, 88–90, 95, 99, 101–102, 105, 230, 232, 246, 248, 256 nodes of the axilla 256 vessels 88, 93, 102, 105 Lymphatic compartment of femoral sheath 104 drain 234 drainage 232–234 of breast 256 system 74 Lymphocytes 49–50, 74–76 Lymphoid tissue 50–51 Lysosomal enzymes 59

Macrophages

48, 50, 76 Magnesium chloride MgCl2 61 Major of pectoralis 221, 224, 227, 230, 241–243, 247, 250, 252–253, 255, 265, 288, 295, 352, 357 Male urethra 39 Malignancy of fundus of uterus 99 Malignant cells 230–231, 246, 250 growth 89 Mammals 47 Mammary gland 225–231, 232–234, 241, 243, 246, 252, 255–256 Mandible 11 Manifestations Colles’ fracture 374 compression of median nerve 330 Erb’s paralysis 268 Horner’s syndrome 266 Manubriosternal 24 Marrow 10, 59, 85 Mast cells 49, 76 Mastectomy operation 272 Mastoid process 12 Maternal placental veins 72 Matrix dense matrix 54 extracellular matrix 43 interstitial matrix 54 interterritorial matrix 53 mineralized matrix 61 Maximum growth 14 pull 14

Exam-Oriented Anatomy Mechanical loading 53 Mechanism during movement 27 of action 368 Medial ½ of the calcaneum 217 head of gastrocnemius 135, 137, 141, 143, 146–148, 161, 198–199, 203 longitudinal arch 167, 211, 214– 216 rotator 126, 155, 269, 273, 352, 357 Medially 80, 89, 94, 104, 142, 200, 243, 278, 320–321, 323, 325, 333, 362, 366, 375, 377 Median antebrachial vein 291 atlantoaxial joint 27 cubital vein 289–291, 313, 315 nerve 249, 253, 259, 264, 271, 285, 292, 298–299, 308, 312, 315, 317, 325–331, 341, 362 trap 334 Medium nodes (level 2) 232 Medulla 74–75, 258 Medullary cavity 3, 4, 8, 16, 223 cavity of tibia 147 Membrane areolar 92 interosseous 19, 22, 148, 166, 304, 320, 328, 331, 351, 365–367 krause 68 mucous 51 plasma 43 ruffled 59 serous 37 Meniscofemoral ligament 192, 196–197 Meniscus 55, 152, 195–196, 198– 199, 201 Mesoderm 229 Metacarpal 4, 5, 12, 222, 316, 321, 338, 349, 355, 375 Metacarpals of medial four fingers 335 palmar and dorsal interossei 338 Metacarpophalangeal joint of middle finger 374 Metachromatic staining 55 Metaphyseal artery 16 Metaphysis 12–14, 16 Metatarsals 4 Methyl prednisolone 376 Metric measurement 30 Micro circulatory units 33 glia 48 organisms 50 scope 68 scopy 56, 64, 229 villi 38, 42 Mid axillary line 225, 234, 236 carpal joint 372 flexion of elbow joint 367 inguinal point 98, 107, 116 palmar 349 prone forearm 272 tarsal joints 214 Middle arm 297, 309, 324, 345 band 357 border of tibia 168 cells 39 collateral artery 310 distal phalanges of ring finger 332

fibers 206, 237, 239, 273 finger 285, 305, 330–331, 337– 338, 374 forearm 330, 378 front of the arm 331 genicular nerve 135, 138, 147, 194, 197 genicular vessels 135, 138, 194, 197 of sacrum 11 of shaft 16 part of the clavicle 271 radioulnar joint 22, 364, 365, 366, 369 supraclavicular nerve 223 trunk 263 1/3rd of forearm 304 1/3rd of shaft of humerus 273, 309 Middle fibres of deltoid (acromial) 357 Midline joints of body 23 Midpoint of the crest 84 Mild trypsin digestion 67 Milk ridge 231 Mineralized matrix 61 Miner’s elbow 34 Miniature long bone 4, 5, 12 Minor arteries 228 contents 315 muscles converge 278 Mitochondria 41, 67 Mitosis 40 Mnemonics 195, 268 Mobility 19, 378 Moderate sized ducts of salivary gland 42 Modifications 90, 243 Monocyte 48 Mononuclear cells of the bone marrow 59 Montgomery 226 Morphological 168, 223 Morphology 37, 39, 124, 174, 193, 273–274, 335, 338, 340 Morrant Baker’s cyst 34 Mosaic 37 Motile 42 Motor brachioradialis 305 extensor carpi radialis longus 305 loss 116, 151 nerve of flexor compartment of arm 294 twigs 114 Mouth of femoral canal 104 Movable joints 20 Movement of bone 367 hand 345 lateral end 282, 283 locking 203 medial end of the clavicle 282, 283 mid carpal joint 372 particles 38, 42 scapula 282 shoulder joint 275 unlocking 203 wrist joint 31, 372 Mucous membrane 51 Muller’s muscle 266 Multi axial 186, 356 layered epithelium 39 locular adipose tissue 41 nucleated 48, 61, 64 parous woman 106 pennate muscle 29, 168, 217, 273

Muscle 1st dorsal interosseous muscle 163 accessory 31, 201, 208, 242, 373 adductor magnus muscle 83, 118 adjacent 16 arm 299 biceps femoris 150 bulkiest 128 cremaster 79 cross the same site of axis of rotation 31 cubital fossa 303 deltoid 252, 273–274, 277, 281 extensor carpi radialis brevis 309 extensor compartment muscle 303 flexor digitorum superficialis 168, 327 gluteal 127–128, 160 hamstring 124, 155–157, 189, 200 hypothenar eminence 321, 332, 345, 353–354 inferior gemellus 81 inspiration 242 involved 330 obturator muscle 188 paralysed 130, 149, 268–269, 272, 309 peroneus longus 150, 214 producing movements 206 psoas major 121 quadrilateral 127 sole 29, 149, 170 superficial transverse 124 supinator 304, 307, 350 surrounding the joint 25 thenar 322, 328, 329, 334 thenar eminence 285, 326, 333, 348, 353, 354, 375 thenar space 348 Muscles of anterior compartment of thigh 88 medial compartment of thigh 94 Muscular branch to 1st lumbrical 328 brachioradialis 301 flexor carpi ulnaris 332 medial half of flexor digitorum profundus 332 median nerve 315 muscles of fossa 138 quadriceps 98, 112 sartorius 96 supinator 315 Muscular actions 3 artery 16, 69–70, 110, 312 dystrophy syndrome (Duchenne muscular dystrophy) 130 flexor carpi ulnaris 332 flexor carpi radialis 312, 332 palmaris longus 312, 315 veins 96 Musculo aponeurotic passage 117 cutaneous nerve 249, 259, 264, 269, 293–296, 297, 315, 363 tendinous cuff of shoulder joint 275 Musician’s nerve 345 Myocardial infarction 33 Myocyte 66–67 Myofibril 28, 65–68 Myoglobin 67

Index Myosin filament Myotropy 295 Myxedema 334

Nail

295

beds 33, 149, 353 crack 270 Narrow origin 28 strip 308 zone 270 Navicular bone 166, 207, 211, 216 Navy and nerve 237 NCAMs (neural cell adhesion molecules) 43 Neck of femur 13, 85, 109, 187–188, 190 fibula (postaxial bone) 150 humerus 223, 275, 277, 280, 282, 295, 356–357 radius 299 talus 208, 209, 210 Necrosis of head 13 Neighbouring arteries 33 mucosa 7 tendons of flexor digitorum profundus 340 Nelaton’s line 125 Neonates 267 Neoplasia 334 Nerve ascend 250 bell 234, 264 cells 43 entrapment 123, 355 especially vulnerable 284 extensor compartment of the arm 302 fibres 260 flexor muscles 345 impulse 30 injuries of upper limb 271 latissimus dorsi 249, 260, 265, 268, 269 median and ulnar 322 obturator 25, 80, 111, 116–118, 120–123, 127, 135, 138–139, 188, 197 palmar surface of hand 335 perforating cutaneous 127 piercing 295 plexus 257, 260, 279 pudendal (S2, S3, S4) 80, 127, 157 rhomboids 259, 264–265 roots serratus anterior 234 saphenous 98, 109, 112, 114, 116– 119, 157, 164, 180, 183 sciatic nerve (L4, 5, S1, S2, S3) 80, 127, 155 simulating ganglion 280 subclavius 238, 259, 264, 267, 379 superficial peroneal nerve 159, 162–163, 177 superior gluteal nerve (l4, 5, S1) 80, 126–127, 132 Nerve posterior branch of medial femoral cutaneous nerve 116– 117 cutaneous nerve of thigh (S2, S3) 127, 157 femoral cutaneous nerve 80, 137, 160 Nerve supply of hip joint 185 lumbricals 172, 339 muscles of thenar space 348

Nerve sural communicating nerve 137–138, 149, 159 obturator internus (L5, S1, S2) 80, 127 pectineus (L2, 3, 4) 98 pectineus 103 quadratus femoris (L4, 5, S1) 80, 127, 157 vastus medialis 113–114, 118 Network of nerves 257, 261 Neuroma of the femoral nerve 114 Neurovascular structures 282 Neutrophils 50 Nipple 226, 232, 233–234 Nodule 75 Nomenclature of brachial plexus 258, 263, 379 Nonarticular surface 8 Noncommunicating 34 Nonhealing ulcers 182 Nonmotile 42 Nonnourishment 53 Nonshivering thermogenesis 48 Nucleus 38, 40, 41, 47, 48, 49, 50, 51, 60, 61, 66 Number of bones 25, 26, 190, 204, 356, 361, 365, 370 fibrous 128 Nutrient artery 11, 13, 14, 63, 295, 310, 331 branch to humerus 299 humerus 299, 310 radius 319 ulna 319 Nutrient foramen of femur 83 fibula 11 Nutrition of the organ 33 Nutritional disturbances 33

Oblique

axis 209–210, 211 band 324 cord 365–366 fracture of the lower part of the fibula 207 head of adductor pollicis 343 popliteal ligament 135, 138, 191, 197, 204 Obliquity of superior articular surface 364 Obturator canal 121, 123 externus 120–121, 188 foramen 121 hernia 123 internus 80, 124, 127, 157, 188, 190 muscle 188 nerve 25, 111, 116–118, 120–123, 135, 138–139, 185, 188, 197 notch 121 Occipital bone 21 Occluding 44 Occurrence 54 Odontoid process of axis 27 Oedema of leg 141 Oesophagus 42 Oestrogen 228, 229 Oily secretion 226 Old age 53, 106 Olecranon bursitis 34 fossa 361 process of ulna. 34, 355 Omohyoid 243, 270 Opalescent appearance 55 Opaque appearance 56 Open reduction 374

389 Opening door 377 eye 266 Opponens digiti minimi 344–345, 353–354 pollicis 272, 285, 325, 329–330, 334, 348, 352, 375 Opposition movement of the thumb 285 opponens pollicis 375 thumb 285, 330 Optimum level 213 Oral cavity 40 Orangutan 285 Orcein 57, 75 Organic elements 61 Orthopaedic clinics 376 Ossei bone 338 Osseo fibrous ring 365 Ossification of sutural membrane 22 Osteoblast 10, 60 Osteoclasts 59–61 Osteocytes 59–63 Osteogenic 11, 60–61 Osteomyelitis 13, 17, 123, 141 Osteomyelitis children 14 Osteon (haversian system) bone 59, 62 Outer border 213, 216, 218, 247, 253 circumferential around bone 59 cortex 75 fibrous layer 10 layer all compact bones 63 lip of entire iliac crest 90 side of palm 351 sloping area 84, 128 table 7 Outstretched hand 235, 373, 374 Oval-shaped nodules 7 Ovary 81, 231, 234 Over head abduction 239, 282–283 lying skin 34, 146, 174, 231 use syndrome 156 Ovoid cells 49–51 Oxytocin 229

Packed fibres 10 Pad of fat 139, 192 Pain fibres 11 Paget’s disease 11 tenderness over lateral 363 Painful arc syndrome 355 Paired maxilla 7 spinal nerve 261 Palatomaxillary 21 Pale staining germinal center 75 Palm medial rotation 375 Palmar aponeurosis 174–175, 323, 335, 341, 349, 378 arches 32 aspect 340 branch 316, 323, 333, 341, 343 carpal arch 319, 343, 373 digital branches 327, 329, 341– 342, 353 fascia 322 interossei 29, 332, 337–339, 350, 353 longus 362 metacarpal arteries 341–343 spaces 349 Palmar cutaneous branch of median nerve 323, 333 ulnar nerve 318, 323, 333

Palmar and dorsal interossei 170, 272, 338, 350, 353–354 radiocarpal ligaments 370 Palmar surface lateral 3½ fingers 334 medial 1½ fingers 334 median nerve 334 ulnar nerve 334 Palmar surfaces of carpal bones 333 Palmaris brevis muscle 347 longus tendon 333 Palpable 163, 199, 271, 292 Palpating peripheral pulsations 30 Palpation 139, 292, 313, 330 Para cortical areas 74 Paralysed 130, 132, 149, 268–269, 272, 309, 330, 347 Paralysis bicep brachii 295 deltoid muscle 277 dilator pupillae muscle 266 extensors 309 interossei and lumbricals 347 muscles of thenar eminence 285 of extensor muscles of the wrist joint 309 serratus anterior muscle 237 Paralyzed patients 125 Paranasal sinuses 7 Parasternal group 233–234 Parenchyma 226, 233–234 Paresthesia 354 Parietal bone 21 suture 21 Part of anal canal below the pectinate line 89 capsule of the wrist and carpal joints 328 deltoid muscle 281 dermatome 307, 332 intercondylar area of tibia 194 vagina below the hymen 89 Partial flexion 91 paralysis of brachial plexus 260 tearing 376 Parts of brachial plexus 263 Passage of anterior interosseous vessels 366 Passing inwards 246 outwards 246 Patella 7–9, 34, 90, 116–117, 190–191, 197–198, 202 Patellar bursa 34 subcutaneous 202 Patent 73, 145 Pathology 89–90 Pearshaped 40 Peau d’orange 231 Pectin pubis 90 Pectineus 95, 98, 103–104, 109, 111– 112, 120–122, 185, 188 Pectoral fascia 227, 255 girdle 264, 283, 378 Pectoralis major clavicular head 221 sternal head 221, 352 Pectoralis minor muscle 232, 250, 253, 255 Peculiar to skull 20 Peculiarity 67, 350 Peg 20, 22

390 Pelvic girdle 185, 188, 378 Pelvis of the kidney 41 to knee joint 121 Pennate muscles 28–29 Percutaneous 374 Perforating arteries 109, 154, 338, 343 branches of profunda femoris 83, 94, 96, 99, 111, 155, 159 cutaneous nerve (S2, S3) 127 Perforator vein 291 Periaround 9 Perichondrium 52–57 Perineal region 93 Periodontal membrane 19 Periosteal artery 14, 16 Periosteal vascular plexus 11 Peripheral circulation 164 eye 330 heart 168 light band 28 margin of glenoid cavity 357 nuclei 65 oedema 146 Periphery (cortex) 74 Peritoneal branch to lateral pelvic wall 121 cavity 231 lymph plexuses 231 Peritonitis in the lateral pelvic 123 Permanently extended 284 Peroneus brevis 150, 161, 163, 207, 210, 214 longus 29, 150, 159, 161–163, 170, 177, 199, 206–207, 210–211, 214, 216, 218 tertius 29, 150–151, 161–162, 206, 208, 210–211, 214 Perpendicular 375 Pes anserinus (sebaceous cyst) 141 cavus 174, 213, 216, 218 planus 213, 216, 218 Phagocytize antigen 51 Phagocytose 50 Phagocytosis 48 Phalanges 4, 5, 10, 172–173, 175, 332, 347 Phalanx 173, 175–176, 224, 330, 332, 335–338, 340, 347 Pharynx 40 Phrenic nerve 238, 270, 359 Phylogenetically 7, 199, 335 Pial veins 72 Piece of bone 11 wood 21 Pigment cells 76 Pillar 215, 217 Pillars of carpal tunnel 333 Piriformis 80, 83, 85, 125–126, 156– 157, 159, 188, 190 Pisiform bone 320, 322, 323, 370 Pivot joint 27, 367 Plantar aponeurosis 173–175, 214–215, 218, 335, 378 fasciitis 174 flexion 151, 162, 168, 177, 206, 208–210 flexors of ankle joint 206 interossei of foot 173 Plantaris 135, 137–138, 143, 145– 147, 161, 169, 174, 201, 208 Plasma cells 49, 76 membrane 43

Exam-Oriented Anatomy Platysma 253 Plexus branches 263 Pliability 215 Pliable platform 213 Pneumatic bone 7 Pointing index finger 330 Poland’s syndrome 242 Policeman tip 269 Poliomyelitis 132 Pollicis abductor pollicis brevis 325, 330, 334, 348, 355, 367 abductor pollicis longus 321, 325, 351, 369 adductor pollicis longus 304– 305, 309, 320, 373 adductor 9, 272, 285, 343–344, 346–347, 349 artery 316 extensor pollicis brevis 304– 305, 309, 320, 321, 325 extensor pollicis longus 304, 305, 309, 320–321, 325, 350–351, 367, 372 flexor pollicis brevis 9, 272, 285, 325, 329, 330, 334, 344, 346, 348–349, 355 flexor pollicis longus 9, 29, 224, 323, 328, 330, 332–333, 348, 366, 371, 373 opponens 270, 285, 325, 329– 330, 334, 348–349, 355 Polygonal 37 Polyhedral 39 Poorly defined 73 Popliteal abscess 141 artery 107, 110–111, 119, 121, 135–136, 138, 140–141, 142–146, 149, 155, 169, 191 bursa 198 fossa 99, 134, 136–141, 142, 146– 147, 149–152, 159, 169, 183, 197 groove 152 lymph nodes 139, 141 nodes 89, 105 pulse 140, 145 vein 136, 138, 140–142, 147, 183 Popliteus 135, 138, 142–143, 146– 147, 151–153, 161, 177, 191–192, 196, 201–202, 204 Pores 66 Portal veins 71 Position arm 268 axis 367 bone 204, 367 forearm 368 hand 330 radius 367 Post fixed brachial plexus 261–262 menopausal age 232 Posterior arch of atlas 27 aspect 137, 151, 155–157, 169, 235, 265 axillary fold 247–248, 250 axillary nerve 249, 260, 268, 269, 274, 277, 280, 281, 302, 359 band 198, 362 boundaries of axilla 357 brachial artery 302, 361 brachialis 298 branches 297 branch of medial femoral cutaneous nerve 116– 117

carpal 319–320, 373 chest wall 235 circumflex humeral artery 248, 251, 280–281, 286, 299, 310, 359 cord of brachial plexus 240, 252, 274, 279–280, 302, 359 cruciate ligament 153, 193–195, 197 deep compartment of leg 161 dislocation (dashboard injury) of hip joint 190 femoral cutaneous nerve 80, 137, 160 fibers of deltoid 85, 352, 357, 358 flexor digitorum superficialis 304, 342 gluteal line 128 lamina 241, 245, 246 lateral to styloid process of radius 288 layer 243 ligament 375 long head of triceps 298 longitudinal strip 261 lymph nodes 232, 256 medial head of coracobrachialis 298 upper trunk 263, 267 vein of calf 182 Posterior border of deltoid 281 femur 81 lateral 1/3rd of clavicle 239 Posterior cord of brachial plexus 240, 252, 274, 279–280, 302, 359 Posterior cutaneous nerve of arm 304 forearm 305 thigh (S2, S3) 127 Posterior descending artery 361, 363 branch of the profunda brachii artery 361 Posterior intercostal arteries 228 lymph nodes 232 veins 228 Posterior interosseous artery 320, 361, 373 branch 304, 309, 315 nerve 302, 304, 305, 312, 325, 350, 351, 365, 367, 373 Potential arterial anastomosis 32 weakness 104 Pott’s fracture 207 Power of extension of wrist joint 307 Powerful rotator 235 Practical significance 290 Pre auricular sulcus 81 dominate 71 fixed 257, 261, 262 Pre-axial bone 377 border of the upper limb 287 superficial vein 287 Precise 30, 133, 330 Precisely aligned 28 Precursors of osteoblasts 60, 61 Preferential 33 Prefixed plexus 262 Presence of cartilage 25, 26 Pressure epiphysis 12 points 10 Primary cartilaginous joint (synchondrosis) 23

centre of ossification 18 osteon 62 Prime mover 30, 31, 206 Princeps pollicis artery 318 Process scapula 12, 221, 222, 275, 293 ulna 34, 355, 370 Profunda brachial artery 298, 311 vein 311 Profunda brachii artery 302, 310, 311, 361, 363 deep 310 vessels 279 Profunda femoris vein 96, 98, 108 Profundus 31, 272, 312, 318, 320, 323, 328, 331–333, 340, 342, 345, 347, 354, 360, 366, 371, 373–374 Profuse 57 Progesterone 228, 229 Prognosis 232, 284 Progressive flexion 335 Prolactin 229 Prolongation 7 Prominence of greater tubercle of humerus 282 Prominent nucleolus 50 Pronation of forearm 330, 364 Pronator quadratus 318, 328, 364, 366–367 Pronator teres humeral head 222 ulnar head 222 Proportional 30 Proprioceptive branch to brachialis 301 Propulsion of body 216 Protective structure 355 Protein accessory 28 elastin 57, 75 polysaccharides 61 Proteoglycans 55 Protraction 236, 259, 282 Protrusion of abdominal viscera 100 Proximal arm 378 attachments 128, 132, 162, 166– 167, 174–176, 234, 238– 240, 273, 292, 339 distal 3 bones 320, 321 distal interphalangeal joint 337 palmar crease 343 perforating arteries 338 row 322, 333 segment (femur) 378 thigh 378 Proximal end of 2nd metacarpal 12 5th metacarpal 12 exposure 271 index fingers 305 joint 31 lateral ½ of middle finger 305 Proximal Part of biceps brachii 249 dorsal surfaces of thumb 305 forearm 309, 334 Proximal phalanx of respective finger 338 thumb 330 Proximal surface of base of first metacarpal 375 scaphoid, lunate and triquetral 366 Pseudo ganglion 280, 281, 304, 349 ptosis 266 Pseudohypertrophy 130

Index Pseudostratified ciliated columnar 39 epithelium 39 non-ciliated 39 Psoas major 87, 95, 98, 102, 109, 114, 121, 185, 189 sheath 114 Puberty 225 Pubic branch of inferior epigastric artery 104 crest 90 symphysis 24, 55, 90, 104, 110 tubercle 79, 81, 90, 92, 100, 103, 106 Pubo-femoral ligament 12, 187 Pudendal canal 81, 125 nerve (S2, S3, S4) 80, 127, 157 Pull of the muscle 8 Pulmonary embolism 169 Pulp of fingers 270 little finger 332, 355 Pulpspace 347, 348 Pulsatile midline swelling 141 Pulsations brachial artery 300 in cubital fossa 300 of femoral artery 98, 99, 110 Punching 234, 235, 282 Puncture 290 Purified blood 290 Pus 99, 114, 174, 250 Pushing and punching movement 282 Pyramid shaped area 247

Quadrangular intermuscular

space 277 Quadratus femoris 80, 124, 126, 127, 133, 157, 185, 188, 190 lumborum 84 Quadriceps femoris 8, 9, 88, 111, 112, 114, 116, 117, 198, 199, 201, 204 Quadrilateral muscle 127 Quervain’s tenosynovitis 376

Radial

½ of flexor digitorum profundus 328 bursa 233, 349 deviation of hand 347 groove 298, 301–302, 304, 307, 309–310 lymphatics accompany 289 tendon of biceps 315 tuberosity 12, 366 2/3rd of the dorsum of the hand 304 Radial collateral artery 310, 360 ligament 362–363, 370, 376 Radial nerve 301–308 injury 271, 307 Radial notch of ulna 365–366, 369 on ulna 27 Radial recurrent artery 310, 316, 360–361, 363 branch of radial artery 360, 363 Radial side of index finger 327, 330 profundus tendon 340 Radial ulnar arteries 298, 299, 360, 373 bursa 323, 349 Radialis indicis artery 316 Radius 4, 12, 14–15, 17, 27, 211, 221–222, 288, 298, 304, 309,

319–320, 324, 331, 350–351, 361, 364–370, 373–374, 377–378 Ramus communicans 260, 270 Range of movements 23, 27, 209– 210, 368 RBC 73 Recessus sacciformis 370 Reciprocal innervations 30–31, 60 Reciprocating surface 26 Recording blood pressure 313, 315 Rectangular 38 Rectus femoris 29, 88, 98, 111–113, 116, 126, 133, 185, 188 Recurrent branches of anterior tibial artery 192 deep palmar arch 373 Recurrent anterior ulnar recurrent 320 genicular 150, 159 Redness of conjunctiva 266 Reduction 100, 255, 374 Referred pain 25, 123, 190, 359 Reflected head of rectus femoris 126, 133, 188 Reflex constriction of veins 72 inhibition of deltoid 282 Refractive index 68 Regeneration 57 Regenerative ability 56 Region bicipital groove 356 gluteal 80, 90, 98–99, 125, 128– 129, 132–133, 157–160 perineal 94 radial groove 307 Reiter’s lymph node 230, 246 Relation artery 240 axillary nerve 240 brachial plexus 240 flexor retinaculum 323 gravity 367 ulnar nerve 333, 345 Relations of 2nd part of axillary artery 251 ankle joint (taloc rural) 204 apex of femoral triangle 99 axillary artery 253, 254 axillary nerve 280 bicipital aponeurosis 291 brachial artery 297, 298 brachial plexus 258 carpal tunnel 333 cephalic vein 288, 289 clavi pectoral fascia 243 common peroneal nerve 150 cubital fossa 315 deep palmar arch 343 deep relations of the right mammary gland and its tail 225 dorsalis pedis artery 164 elbow joint 362, 363 femoral artery 108 femoral canal 104 femoral nerve 114 femoral sheath 102 femoral vessels 108 first carpometa carpal joint 375 flexor retinaculum 323 gluteus medius 132 great saphenous vein 180 hip joint 188 iintra-articular structures of right knee joint 193 interossei 338 interosseous membrane 366 ischial tuberosity 124 knee joint 199, 200 lumbricals 341 mammary gland 227

391 median cubital vein 291 median nerve 325 musculocutaneous nerve 294 nerve to serratus anterior 236 nerve to the subclavius 238 obturator nerve 122 pectoralis major 241 plantar aponeurosis 174 popliteal artery 142, 144 popliteal fossa 140 popliteus 152 profunda brachii artery 310 radial nerve 302, 303 right femoral artery 111 sciatic nerve 157, 158 shoulder joint or glenohumeral joint 358 soleus 169 superficial palmar arch 341 supra scapular nerve 237 tibial nerve 146 ulnar artery 316, 318 ulnar nerve 345 vessels 98 wrist joint (radiocarpal) 371, 372 Relaxation of the muscle 16 Renal arteries 33 veins 71 Resemblance 7 Resemble teeth 21 Resilience 215 Resistance 30, 94, 129, 132, 156, 242, 284, 292, 339, 341 Resistant 30, 94, 129, 132, 156, 242, 284, 292, 339, 341 Resonance 7 Respiratory passage 7 Rest 37, 111, 241, 377 Resting peacefully 354 Result of vasospasm 335 Reticular 50, 75, 111 Reticulin 75 Retinacula 187, 191 Retinal veins 72 Retraction scapula 283 shoulder girdle 259 Retroclavicular part 258, 263 Retroperitoneal tumours 123 Reverse of Colles fracture 274 Rheumatoid arthritis 334 Rhomboidal 129 Rich plexus of small veins 168 Riders bone 9 Right intermuscular space 277 Ring fingers 371 Robertson pupil 266 Roof anatomical snuff box 287, 303 cubital fossa 287, 292, 314 Root of brachial plexus 240, 260, 262, 265–266 coracoid process 357 cords 258, 262, 272 divisions 146, 149, 156, 159, 258, 262 lateral 3½ fingers 310 median nerve 249, 259, 264 neck of the tooth 20 spinal nerve 262 thumb 308 trunks 258, 262, 263 value of obturator nerve 112 Rostrum of sphenoid 20, 21 Rotation of knee joint 201 shoulder 368 Rotator cuff 31, 275–276, 352, 356, 359 Rotatory 368

Rounded follicles 74 lymphatic follicles 75 Roundness of shoulder 282 RTDC 262 Rubber catheter 290 Rudimentary 103, 223 Ruffled membrane 59 Runal 260, 265 Rupture of aneurysm of popliteal artery 119 brachial artery 313 transverse ligament of atlantoaxial joint 27

Sacral

joint 24 plexus 156 segments of the spinal cord 132 Sacro iliac joint 22, 85, 130, 378 spinous ligament 81, 85, 131 tuberous ligament 81, 85, 90, 124, 128, 131 Sacrum 11, 90, 126, 128 Saddle shape synovial joint 191, 217, 361, 374 type of synovial joint 362 Sagittal suture 21 Samples of blood 290, 313 Saphenous artery 110, 114, 118 nerve 98, 109, 112, 114, 116–119, 157, 164, 180, 183 opening 79, 90–93, 95, 100, 103, 106, 180 Sarcolemma 64 Sarcoma 141, 160 Sarcomere segments 67 Sarcoplasm of skeletal 28, 67 Sarcoplasmic reticulum 66 Sartorius 83, 85, 87–88, 94, 96, 111– 112, 117, 119, 133, 137, 141, 191, 200–201, 203 Saturday night palsy 307, 309 Scalenus anterior 258, 270 medius muscle 236–237, 258 Scaly skin 270 Scaphoid lunate 5, 366, 369–370 trapezium 320–321, 333, 370 triquetral bone 370 Scapula forward 235, 240 hypoplastic 271 laterally 235 Scapular anastomosis 278 instabilities 284 region 257, 277–278 Scapular 236, 255, 257, 259, 261, 264–265, 273, 277–278, 284, 286 Schindylesis 20–22 Sciatic nerve 80, 127, 156–160 Scissors gait 123 Screw driver 369 Scrotum in male 110 Seam 21 Sebaceous glands 226 Secondary cartilaginous joint 19, 23, 24 centre of ossification 12, 18 osteon 62 ovarian follicles 42 Secretion 38, 226, 230 Segmentally 168, 234, 236, 261 Segments of brachial plexus 269 Seldom due to tennis 376 Selectins 43

392 Sellar or saddle joints 26 Semi flexed 201, 368 flexion of the elbow joint 30 lunar 72, 195 membranosus bursa 34 tendinosus 124, 127, 135, 137, 141, 155, 157, 160, 189, 200–201, 203 Sensations pulp of little finger 355 skin 112, 279, 282 Sensory articular branch 304 interosseous membrane 351 radius 351 twigs 114 Separation of epiphyseal plate 13 upper end 13 Septic arthritis 14 Septum 54, 87, 104, 168, 226, 302, 310, 345, 349 Serous cavities 37 membrane 37, 51 Serrate 20, 21, 22 Serratus anterior 227, 234–237, 239–240, 242, 247–248, 253, 259–260, 264, 271, 282–284, 357, 379 posterior 265 Sesame seed-like 7 Sesamoid bone 7, 9–10, 162 Severe pain 146, 149, 377 Severity 260 Shaft of femur 133 humerus 248, 273, 278, 307, 309 long bone 13, 17, 63 metacarpal and interossei 343 radius and ulna 365–366 Shaking hands 377 Shallow groove 83, 302 pits 59 triangular fossa 313 Shape of articulating bones 26 bony margins 20 surfaces 20, 25 Shaped pear 40 umbrella 40 Sharpe’s fibers 63 Sheath axillary 243, 246, 271 connective tissue 65 fascial 349 femoral 92, 95–96, 98–99, 101– 102, 104, 108, 114, 182 fibrous 173, 347, 275 psoas 114 rectus 234 synovial 319, 323, 356 Shock absorbers 19 absorbing cushion 48 Short adductor pollicis 349 bones 5, 18 cells 39 flexor pollicis brevis 349 head of biceps femoris 82, 150, 159 muscles of thumb 349 opponens pollicis 349 plantar ligament 214, 218 Shortening of the palmar aponeurosis 174, 336 Shoulder dislocation 260 dystocia 267

Exam-Oriented Anatomy girdle 259, 357 joint 26, 31, 34, 237, 242, 255, 259, 269, 273, 275–277, 280–282, 293, 295, 299, 352, 355, 356–359 neck injuries 284 region 273, 275 tip pain 359 Shoulders pass 267 Shrugging 239, 282 Side of 2nd part of axillary artery 263, 345 Side of dorsum of hand 308–309 Signifies 115, 266, 281, 303, 306, 326, 329, 346 Signs benediction 330 Silver staining 75 Simple columnar epithelium 38, 39 squamous epithelium 37, 70 synovial 24, 365 Simulates 271, 280 Simultaneous contraction 31 Simultaneously 30, 153 Single bone in the proximal segment (humerus) 378 epiphysis 12 large droplet 46 Sinking of eyeball 266 Sinus tarsi 209–211 Site of ligation of femoral artery 119 Skeletal muscles 64, 66 Skeleton 3, 4, 7, 54, 223–224, 378 Skilled movements 353 Skin of digital pads 33 dorsal surface of 1 ½ finger 332 hypothenar eminence 345 lateral side of forearm 295 limbs 261 medial one and half fingers of 345 medial side of thigh 112, 121 palmar aponeurosis 349 shaft of penis over 89 thenar muscles 328 upper limb 261 Skull 19–21, 55 Slight degree of movement 20, 22 dorsiflexion 334 Slightly movable 20 Slings 216 Slogan 15, 17 Small aponeurosis 336 area of anesthesia 310 blood vessels 65 isolated lymph nodes 315 minor trauma 376 muscles of hand 269, 271, 345 saphenous vein 179, 182–183 sensory loss 308 veins 72, 168 Smaller bony areas 378 radial artery 312 Smallest branch of brachial plexus 297 Smith’s fracture 374 Smooth involuntary muscle 64 muscles 64, 71 unstriped 64 Socket 20, 22, 26, 186–187, 215, 355–356, 361 Socket joint 20 Sole of foot 113, 140, 149, 170, 177

Soleal arch 167, 169 line of the tibia 168 sinuses 168, 169 Soleus 138, 143, 145–147, 161, 167– 169, 206, 208 Somatic nerves 11 Source of blood supply 85, 111 hormone 46 Space lined 34 Sparse 56 Spasm of adductors of thigh 123 Spastic paraplegia 123 Specialized 33, 61, 65, 67 Sphenoid 7, 20, 21 Spheno-occipital 23 Spherical nucleus 41, 48, 50 Spheroidal joints 26 Spina bifida 213–214, 216, 218 Spinal cord 31, 38, 42, 150, 167, 169, 260 nerve of the respective region 261 part of accessory nerve 239 Spindle shaped 47 Spine 79–80, 83–85, 103, 106, 109– 110, 125, 160, 187, 237–239, 273 Spines of C7 to T12 vertebrae 239 tibia 202 Spinous anastomosis 109 Spiral line 82 muscle 240 Spiraling 75 Spirally twisted 367 Spleen 33, 74–75 Splinting of the wrist 334 Spongy bone 16 substance 7 Spontaneous 284 Sprain of radial collateral ligament 363, 376 Sprengel’s deformity 371 Spring ligament 207, 212, 214, 216 Squamous cells 37 Squaring of the shoulder 283 Stab injury 236 wounds 99, 160 Stability of knee joint 202 patella 202 shoulder joint 352, 356, 359 Stable condition 374 movement 203 Staining methods (orcein stain) 57 Staples 211, 216, 218 Steadies head of humerus 276 scapula 239 Stellate cells 50 Stepwise fashion 65, 67 Stereocilia 42 Sternal fibres 242, 296, 357 head of pectoralis major 352 Sternocostal head 240 part 242 Sterno clavicular joint 26, 55, 238, 282, 378 cleidomastoid 270 xiphisternal 23 Sternum 23, 221, 224, 225, 240–241, 243 Sticks to capsule of shoulder joint 276

Stiff door handle 376 Stillbirth 18 Stimuli 66 Storehouse of energy 48 Straight 21, 65, 75, 85, 176, 305, 307, 354, 377 Strain 14, 216, 376 Strain of the muscle 14 Strangulated hernia 104 Stratified squamous epithelium 39–40 keratinized 39 non-keratinized 40, 42 Stratified columnar 42 cuboidal 42 multi-layered epithelium 39 Strength greater 367 less 338 Stress fracture 9 strain and tension 14 Stretch reflex 31 Stretching of the periosteum 11 Striated cross-striped 64 involuntary muscle 64, 66 voluntary muscle 64 Strip of skin 305 Stroke 235, 237, 284 Strong binding 45 fascia 117, 152, 248 fibrous band of deep fascia 323 protractor 235 Structural end arteries 33 Structure cubital fossa 315, 326, 362 deep 103 going to gluteal region 80 of ring 27 passing 80, 92, 169, 277, 278– 279, 325 piercing 93, 102, 174, 246 Students elbow 34 Styloid process of fibula 198 radius 288, 370 ulna 370 Sub acromial bursa 355, 358–359 chondral osseous lamina 53 clavius 227, 238, 242–243, 245– 247, 255, 259, 264, 267, 289, 379 coracoid dislocation of humerus 272 deltoid bursae 275 diaphragmatic 231 fascial 34, 94 luxation of superior radioulnar joint 27, 369 muscular 34 talar joint 163, 167 tendinous 34 Subclavian artery 70, 227, 253, 271, 286, 359 groove of clavicle 242 nerve 238 trunk 256 vein 228 vessels 238, 250 Subcutaneous arteriovenous fistula 290 bone 85 fat 347 infrapatellar 202 tissue 287 Subsartorial canal 117 plexus 116, 117, 121

Index Subscapular artery 248, 278, 359 bursa of shoulder joint 34 circumflex 255 fossa 286 nerve 253, 269, 359 space 75 vessels 256 Subscapularis anterior 280 front 277 muscle 248 teres major 268, 302, 352–353, 356–357, 359 Subendothelial connective tissue 71 layer 70 Substance of opponens digiti minimi 345 peroneus longus muscle 150 psoas major muscle 121 scalenus medius 236 Successive z bands 28, 67 Summit 215, 217 Superficial branch of radial nerve 319, 321– 322 branch saphenous artery 118 branches of femoral artery 92, 94, 102 cells 39, 40 circumflex iliac artery 92–94, 102 compartment of leg 150, 162, 168 group of muscles 318 inguinal lymph nodes 89, 95 lamina 91 major part (3/4th part) 128 palmar arch 317, 319–320, 341– 342 palmar branch of radial artery 323, 333, 341 palmaris longus 371 peroneal nerve 159, 161–163, 177 radial nerve at wrist 309 temporal artery 32 tendons of index and little fingers 369 terminal branch of radial nerve 302 tibiotalar ligament 208 veins 168, 183 Superficial deep branches of radial nerve 308 clavipectoral fascia 250 groups of flexor muscles of forearm 331 head of pronator teres 326 lateral cutaneous nerve of forearm 288, 313 layer of fascia lata 79 muscles of forearm 327, 331 Superficial epigastric artery 92, 94, 102 vein 92, 94 Superficial extensor muscles 376 retinaculum 288 Superficial external pudendal artery 92, 93 vein 92, 93, 94 fascia 94 Superficial flexor carpi radialis 371, 373 ulnaris 371, 373 Superficial flexors of forearm flexor carpi radialis 331 flexor carpi ulnaris 331 flexor digitorum superficialis 327, 331

palmaris longus 331 pronator teres 331 Superficialis muscle of the forearm 168, 331 flexor digitorum 318, 323, 327, 328, 330–331, 333, 342, 347 Superior angle 147, 159, 232 articular surface 364 band 357 border of scapula 245 crus of saphenous opening 79 fibres 130 gluteal nerve 80, 126, 127, 132 gluteal vessels 80 gluteus minimus 188 hand 335 iliac spine 83–85, 103, 106, 109– 110, 125, 160, 187 lateral genicular 150, 159 nuchal line 238 radioulnar joint 26–27, 360, 362, 364–366, 369 reflected head of rectus femoris 188 surface of calcaneum 217 surface of talus 204, 205 talus 204–206, 208 thoracic 228, 251, 255 tibiofibular joint 147 ulnar collateral artery 298–299, 345, 361 ulnar collateral branch 361 vena cava infusion 288 wall 248 Supernumerary breast 231 nipples 232 rib 271 Supero lateral part of uterus 89 medial margin of glenoid cavity 357 Supination pronation 27, 363, 367–369 pronation movements 367 Supinator 269, 293, 304–305, 308– 309, 314–315, 350, 362, 364, 367 Supine position 330 Support of knee joint 91 Supra clavicular lymph nodes 233 nerve 221, 253, 261, 359 part 258, 270 Suprascapular foramen 237 ligament 237 nerve 237–238, 248, 257, 269, 359 Supra condylar fracture of humerus 299, 313, 315 glenoid tubercle 275, 293, 356 patellar bursa 198 spinatus 237–239, 259, 268–269, 275–276, 352, 355–357, 359 spinous fossa 238, 286 Sural arteries to gastrocnemius 136, 138 branch of popliteal artery 169 communicating nerve 137–138, 149, 159 cutaneous artery 145 nerve 137–138, 147, 159, 164, 177, 184 Surface anatomy 83, 84 concave 53 convex osseous 53

393 dry 40 long bones 3 tautened tendon of extensor pollicis longus 302 Surface of arm 305 body of atlas 27 clavicle 240, 243, 247 forearm 296, 333 interosseous membrane 304 lower end of radius 369 subclavius 238 talofibular ligament 210 wet 40 Surgeon 18, 104, 290 Surgery cancer of breast 290 Surgical approach 119, 270, 295, 308 intervention 83, 284 neck of humerus 275, 280, 282, 356 procedure 271 removal of axillary lymph nodes 284 Surrounding muscles 352, 359 tissues 53, 72 Suspensory ligament of axilla 227 cooper 233 Sustantaculum tali of calcaneus 211, 216 Suture stitch 21 Suturing material 91 Sweat gland 225 Sweating 266 Swelling 34, 103, 106, 141, 260 Swimmer’s palsy 235, 239, 284 Swimming 235, 284 Symmetrical 206, 297 Sympathetic branch 331 contribution 266 filaments 328 ganglion 270 innervation 266 nerve 260, 266 nervous system 47, 266 Symphysis 19, 23 Symptoms 169, 376 Synarthroses 19 Synchondrosis 19, 23 Syncytium 66 Syndesmosis 19–20, 365–366, 369 Syndrome 123, 130, 149, 156, 159, 160, 169, 242, 266 Synergistic muscles 31 Synergists 31 Syn-fusion 22 Synonymous 69, 70, 271, 273, 279, 355 Synovial cavity 198 fluid 8, 19–20, 25, 34, 52, 197 joints 19–20, 24–25, 27, 53, 186, 204, 215, 217, 356, 361, 366, 369, 374 lining 376 membrane of knee joint 141, 197 membrane of subscapular bursa 356 recess sacciformis 365 Synovial articulation 355 System central nervous 48 lymphatic 74 sympathetic nervous 47, 266 haversian’ s 8, 16, 59, 60, 62–63

T tubules T1

66

large 255, 262 reduced 262 root 262 Talipes calcaneovalgus 211, 214 calcaneovarus 210, 211 calcaneus 213, 216, 218 club foot 210 equinovarus 210–211, 213–214, 216, 218 equinus 213, 216, 218 valgus 213, 216, 218 varus 213, 216, 218 Talo calcaneonavicular 209, 211, 215 navicular 26 Talus 6, 12, 18, 164, 166, 204–210, 212, 214–215 Tarsal bones 6, 18, 164, 166, 207 tunnel syndrome 149 Tautened tendon of extensor pollicis longus 304 Tear of common extensor 376 Tearing of the fibres 376 Temperature 7 Temporary nature 23 Temporo mandibular joint 26–27, 53, 55 parietal suture 20 Tenderness 11, 363, 374, 377 Tendinous arch connecting 347 Tendo achilles 177, 206 calcaneus 167–169, 180, 183 Tendon of 4 superficial flexor 327 adductor magnus 83 arising 376 biceps brachii 295 brachioradialis 304 coracobrachialis 300 digits 327, 343 extensor pollicis brevis 320– 321, 376 flexor carpi radialis 327 flexor digitorum longus 170, 176, 218 flexor digitorum profundus 332 flexor digitorum superficialis 332 long head of biceps 356, 358 palmaris longus 323, 327, 335 pollicis longus 9, 320 radial side of wrist 327 Tennis elbow 363, 376–377 players 376 Tensile forces 54 strength 55 Tensor fascia lata 90, 91, 190 201– 202 Tent intact 248 Teres major muscle 248, 253, 268, 277–278, 280, 295, 297, 302, 353, 357 minor muscle 31, 268, 275–281, 352, 356, 358–359 Terminal arterioles 32, 148 branches 80, 158, 171, 305, 310, 316, 320, phalanx 330, 347 Terminal branches of anterior and posterior tibial artery 142, 169

394 medial and lateral plantar 148 posterior cord of brachial plexus 279 radial and ulnar arteries 299, 360 sciatic nerve 138, 146, 150, 158– 160 superficial and deep peroneal nerve 159 superficial and deep terminal 302 ventral rami 261 Termination of cephalic vein 287, 289 Territory of the hand 353 Testing finger 339 Texture of cloth 330 Thenar eminence 285, 333, 348, 353–354, 375 Therapeutic purposes 291 Thick fascia of thigh 91 Thickness of the wall 73 Thoracic aorta 228 duct 256 nerve 234–235, 237, 248, 264, 284 region 261 side 250 Thoracoacromial artery 242, 246, 286 Thoracolumbar fascia 84 Thoracotomy 236 Thorax 72, 257, 260, 284 Throbbing pain 347 Thrombosis 141, 146, 169 Thumb 27, 30, 285, 287, 304–305, 307, 321, 329–330, 341, 347–348, 367, 375 Thymus 74 Thyroid 54 Tibia 12–18, 91, 141, 147, 152–153, 155, 166–167, 180, 190–191, 193–195, 198–199, 201– 204, 207–208, 376, 378 Tibial collateral ligament 83, 196, 203 head 168 nerve 136–138, 140, 142, 146– 149, 152–153, 159, 167, 169, 177, 199, 206–207 tuberosity 12, 191, 198 Tibialis anterior 29, 184, 206, 208, 213– 214, 216 posterior 166, 170, 177, 184, 206, 208, 212–214 Tibio calcanean ligament 208 navicular ligament 207 Tie beam 174, 214–215, 218 Timbre 7 Tingling sensations 355 Tip of the little finger 104 Tissue fibers of connective 64 fibrous 7, 19–21, 27, 56, 129 multilocular adipose 41 subendothelial connective 71 vascular 53 Titin 28 Tone 30, 156 Tone of the muscle 30 Tongue 40 Tonic contraction of triceps surae 206 Tonsil 74 Tooth 20, 22 Tortuous 16 Tough 19, 55, 90, 174 Toughness 75 Toxins 40 Toxoid injections 284

Exam-Oriented Anatomy Trachea 39, 55 Tract gastrointestinal 38 upper respiratory tract 39 Traction epiphysis 12, 124 on the arm 267 Transmembrane protein 43 Transient condition 307 Transitional epithelium 40 relax state 41 stretch state 41 Transmission 12, 23, 55, 58, 64, 195, 217 Transmit arteries 16, 188 force 367 weight 3 Transplanted 11 Transversalis fascia 101 Transverse acetabular ligament 186–188 axis 189–190 branch 109, 154 cervical artery 263, 276, 284 head of adductor pollicis 349 humeral ligament 357 ligament 192, 197 Transversus abdominis 84 Trapezium 6, 321–323, 333, 370, 375 Trapezius 235, 237–239, 247, 261, 282–283 Trapezoid 6, 225 Trauma 156, 169, 267, 284, 334, 376 Traumatic 58 Treatment of aneurysm of popliteal artery 119 Trendelenburg’s operation 99 sign 133 Triangular bone 12 facet 205 space 278–279 Tributaries of femoral vein 92, 94 Triceps lateral head 221, 301, 305, 308, 310–311 long head 221, 275, 278, 280– 281, 298, 301–302, 352, 358–359 medial head 221, 301, 304, 345 surae 168, 206 Triglycerides (fatty acids and glycerol) 46 Triquetral 5, 324, 366, 369–370 Triquetrum 370 Trochanter of femur 18, 126, 132 Trochanteric anastomosis 86, 109, 111, 127 bursa of the gluteus medius 132 fossa 85 Trochlear notch of ulna 361 surface of humerus 361 surface of talus 206 Trophic 177, 268 Tropocollagen 75 Trunk axillary nerve 281 brachial plexus 238, 258, 260, 263 Tubercle of humerus 12, 18, 282 iliac crest 91 scaphoid 322–323 Tubercles 226, 274, 357 Tuberculosis 25 Tuberosity of radius 365 ulna 365

Tubular extension 356 Tubuloalveolar gland 229 Tumors retroperitoneal 115, 123 Tunica adventitia 69, 71, 73, 101, 141 intima 69, 71, 73 media 69, 73 Tunnel 117, 323 Twigs 114, 121 Type of synovial joint joints 20, 24–25, 53 plane 25, 209 variety 26, 204, 209, 361, 366, 369, 370, 374 Type birth paralysis 267 fibers 75, 187, 273 muscular dystrophy 284 synovial joint 186, 215, 217, 356, 361, 365–366 Typical claw hand (ulnar claw) 347 long bone 4 synovial joint 24

U-shaped manner

241 Ulnar ½ of the flexor digitorum profundus 354 artery 315, 316–318, 323, 326, 341–342, 344–345, 353, 361, 363 border of arm 271 border of forearm 270, 354 border of hand 270 bursa 323, 333, 349 collateral ligament 362, 370 collateral nerve 304 flexors of the wrist 269 groove 347 head of pronator teres 317 lumbricals 354 nerve 259, 264, 269, 271, 272, 341, 344–347, 353, 356, 344, 359, 360, 363 nerve entrapment 347, 355 notch of radius 369 side of palmar aponeurosis 335 side 272, 335 vessels 333 Ultrasound 110 Umbrella shaped 40 Undue abduction of the arm 269 Unduly palpable 271 Uniaxial 25, 27, 190, 204, 359, 365 Uniaxial pivot variety of synovial joint 366, 369 Unilocular 41, 48 Unipennate 28, 176, 338, 340 Unlocking 153, 201, 203–204 Unpaired 7 Upper part of bicipital groove 241 fibrous capsule 357 front of thigh 94 long head of triceps 281 mammary gland 252 medial head 308 median nerve 298 serratus anterior 248 shaft 275 Upward dislocation of shoulder 355 downwards 261 Ureter 41, 81 Urinary bladder 41, 81 Upper 2/3rd of forearm 345 border of ilium 83 border of vomer 20 compartment 26, 196

end of femur 16, 18, 134 end of humerus 274, 282 end of lesser tubercle 357 end of tibia 16, 18, 141, 194, 198 eyelid 266 fibers of trapezius 282, 283 half of the forearm 298 intercostals 255 intermuscular traingular space 278 limb adducted 269 limb in Erb’s palsy 269 lip of the crest 239 lower fibres 239 lower nerves 260 respiratory tract 39 ribs 250 subscapular 249, 253, 260, 265, 268–269 surface of the coracoid process 240 triangular space 278 trunk 237, 260, 263–264, 267– 269 Ulnaris 9, 30–31, 272, 303, 310, 318, 320, 325, 331–332, 345, 347, 350, 362, 367, 371–373 Ulna 4, 15, 17, 27, 34, 211, 222, 292, 319–320, 324, 331–332, 355, 360–361, 364–367, 369– 370, 378

Vacuoles

41, 59 Vagina 40, 89 Vaginal deliveries 267 Valve flaps 72 Valves 72, 179–180, 182–184 Variable degree of demyelination 355 Varicose ulcer 182 veins 179, 182 Varicosities of saphenous veins 99 Varicosity 182 Variety of synovial joint 204, 209, 361, 370, 374 Various position of hand 330 Vas deferens 39 Vascular branch of the anterior division of obturator nerve 118 branch to posterior circumflex 281 layer 10, 57 necrosis 16, 17, 347 part of bone 14 plexus 11 tissue 53 Vaso active 50 motor changes 270 occlusive diseases of the lower limb 164 Vastus intermedius 81, 88, 98, 112, 114, 116 lateralis 79, 81, 88, 98, 112, 114, 116, 118, 130, 131 medial 79, 82–83, 88, 98, 111– 114, 116–118, 202 Vein anterior cutaneous 182 cephalic 246, 256, 287–291, 313, 321–322 circumflex iliac 92, 182 deep external pudendal 182 epigastric 92, 94,182 external pudendal vein 182 femoral 87, 96, 98–99, 101–103, 105, 108–110, 118, 180, 184 great saphenous 88, 92, 96, 101– 102, 114, 118, 179–184, 289 marginal 180, 183

Index muscular 96 popliteal 136, 138, 140–142, 147, 183 profunda femoris 96, 98, 108 small saphenous 179, 182–183 Veins of abdomen 72 leg 71, 168 thorax 72 trabecular bone 72 Venesection 183 Venous anastomosis 32 blood flow 72 compartment 101–104 drainage of lower limb 183–184 drainage 129, 183, 226 line 290 perforators of lower limb 179 pump 168 spaces of erectile tissue 72 thrombosis 146 Ventral division 5th cervical nerve 267 division 6th cervical nerve 267 division C5, C6, C7, C8 and T1 257 dorsal roots of the spinal nerve 260 part of thorax and upper limb 258 primary rami 111–112, 121, 146, 149–150, 156, 159, 167, 185, 188, 261–262, 269, 271, 280 roots 261, 302 segment 83 Ventrally 339 Verhoeff-Van Gieson stain 57 Vertebral type 20 vein 228 Vertical axis 27, 201, 211 curvature 83

disposition of clavipectoral fascia 244 height 92 septa 103 Vertically 3, 38, 121, 224, 225, 324, 326 Very low-density lipoprotein (VLDL) 46 Vesicular nucleus 47 Vessels arm 250 bleed 11 blood 50 Cloquet lymph 103 common iliac 121 deep lymph 118 femoral 99, 101, 103, 108, 118 inferior gluteal 80, 157 internal iliac 80 internal pudendal 127 limb 271 lower limb 99 lymph vessels 88, 93, 102, 103, 105 middle genicular 135, 138, 194, 197 narrower 105 smaller 80, 103 superficial circumflex iliac 100, 103 superficial epigastric 100 superior gluteal 100 tourniquet popliteal 119 Vestibular 42 Viable 18, 40 Vicinity of cartilage cells 56 Violinists 376 Viral illnesses 284 infection 284 Viscera 37, 100 Viscosity of fluid 25 synovial fluid 25 Visible 56, 64, 182

395 Visualize 270 Vocal cords 75 Volar 322, 347 Volkmann’s canal 60, 63 ischemic contracture 315, 363 Voluntary muscles 64

Wall

299, 313,

62, 69, 71–73, 75, 183, 233– 234, 247, 282, 288, 302 Walls of blood vessel 75 Warmer 270 Wasting interossei 354 small muscles of hand 271, 285, 354 thenar eminence 285 thenar muscles 334 Weak flexor of shoulder joint 293 flexor of knee joint 153 upper part 365 Weakening of protraction of scapula 234 Weakness flexion of elbow 295 muscles of the thenar eminence 333 serratus anterior 284 Weapons 284 Weaver’s bottom 34, 125 Weight bearing and locomotion 193, 195, 378 transmission 12, 23, 55, 195, 217 Well defined 73, 92 Wet surface 40 White adipose tissue 46, 48 fibrocartilage 56, 173 matter 260 ramus 260, 270 Whitlow 347

Wide bored needle 288 Wider pelvis 103, 105 Width 38, 66 Wilhelm Erb 267 Wing distal 337 proximal 337 tendons 337 Winged scapula 235, 283 Winging of scapula 260, 271, 283– 284 Withdrawal arterial blood 313, 315 blood 289, 313, 315 Wound gunshot 116, 260, 267 stab 99, 160, 260 Woven bone 62 Wrist carpal joints 307, 328 drop 271, 278, 307 extensors 377 joint 26–27, 30–31, 55, 307–310, 316, 319–320, 331, 333, 349, 366, 369–374 radiocarpal 373

X-ray

Xiphoid

18 23

Yellow elastic fibers Z

57

disc (Krause's membrane) 68 line 28, 67 Zona orbicularis 187, 188 Zone 1 (superficial or tangential stratum) 52 2 (transitional or intermediate stratum) 52 3 (radiate stratum) 53 4 (calcified stratum) 53 Zonulae occludentes 37