Anatomy for Generic Surgical Sciences Examination (Gsse) 9789811038822, 9789811038839, 9811038821

Table of contents :
Preface......Page 5
Contents......Page 6
Question 1......Page 7
Question 2......Page 9
Question 4......Page 10
Question 5......Page 12
Question 6......Page 13
Question 8......Page 14
Question 10......Page 15
Question 12......Page 16
Question 13......Page 17
Question 16......Page 18
Question 18......Page 20
Part Two: Answers......Page 21
Question 1......Page 33
Question 2......Page 34
Question 3......Page 35
Question 4......Page 36
Question 5......Page 38
Question 6......Page 39
Question 7......Page 40
Question 8......Page 41
Question 9......Page 42
Question 10......Page 43
Question 11......Page 44
Question 12......Page 45
Question 13......Page 46
Question 14......Page 47
Question 15......Page 48
Question 16......Page 49
Part Two: Answers......Page 50
Question 1......Page 62
Question 2......Page 64
Question 3......Page 65
Question 4......Page 67
Question 5......Page 68
Question 6......Page 69
Question 7......Page 70
Question 8......Page 71
Question 9......Page 72
Question 10......Page 73
Question 11......Page 74
Question 12......Page 75
Question 13......Page 76
Question 14......Page 77
Question 15......Page 78
Question 16......Page 79
Part Two: Answers......Page 80
Question 1......Page 89
Question 2......Page 91
Question 3......Page 92
Question 4......Page 93
Question 5......Page 94
Question 6......Page 95
Question 7......Page 96
Question 8......Page 97
Question 9......Page 98
Question 10......Page 99
Question 11......Page 100
Question 12......Page 101
Question 14......Page 102
Part Two: Answers......Page 103
Question 1......Page 106
Question 2......Page 108
Question 3......Page 109
Question 4......Page 110
Question 5......Page 111
Question 6......Page 112
Question 7......Page 113
Question 8......Page 114
Question 9......Page 115
Question 10......Page 116
Question 11......Page 117
Part Two: Answers......Page 118
Question 1......Page 127
Question 2......Page 128
Question 4......Page 129
Question 5......Page 130
Question 7......Page 131
Question 9......Page 132
Question 10......Page 133
Question 11......Page 134
Question 13......Page 135
Question 14......Page 136
Part Two: Answers......Page 137
Question 1......Page 140
Question 2......Page 142
Question 3......Page 143
Question 4......Page 144
Question 5......Page 145
Question 6......Page 146
Question 7......Page 147
Question 8......Page 148
Question 9......Page 149
Question 10......Page 151
Question 11......Page 152
Question 12......Page 153
Part Two: Answers......Page 154

Citation preview

Anatomy for the Generic Surgical Sciences Examination (GSSE)

S. Ali Mirjalili Editor

123

Anatomy for the Generic Surgical Sciences Examination (GSSE)

S. Ali Mirjalili Editor

Anatomy for the Generic Surgical Sciences Examination (GSSE)

Editor S. Ali Mirjalili Department of Anatomy and Medical Imaging University of Auckland Auckland New Zealand

Jointly published with People’s Medical Publishing House ISBN 978-981-10-3882-2    ISBN 978-981-10-3883-9 (eBook) DOI 10.1007/978-981-10-3883-9 The print edition is not for sale in China Mainland. Customers from China Mainland please order the print book from: People’s Medical Publishing House. Library of Congress Control Number: 2017940034 © Springer Nature Singapore Pte Ltd. and People’s Medical Publishing House 2017 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Printed on acid-free paper This Springer imprint is published by Springer Nature The registered company is Springer Nature Singapore Pte Ltd. The registered company address is: 152 Beach Road, #21-01/04 Gateway East, Singapore 189721, Singapore

Preface

Passing the milestone of the Generic Surgical Sciences Examination (GSSE) is an unforgettable experience for any surgeon. Learning enough to “get through” the anatomy component while juggling work on busy surgical units, and maintaining sanity, is mission near impossible. This collection of questions and answers is intended to assist junior doctors in successfully sitting the GSSE. The questions are specifically designed to highlight key surgical anatomy, and are supplemented by images that replicate “spot-test” type questions in the GSSE. Illustrations are used to highlight particular anatomical relationships that are difficult to grasp. The reader can be assured that all anatomical details are in concert with the recommended textbook for the GSSE, e.g., the sternal angle is described at the level of T4 posteriorly (recommended reference) as opposed to other major anatomical textbooks that describe it as T4/5 intervertebral disc. Beyond the GSSE, this resource will be invaluable for those undertaking study for specialty-specific anatomy examinations, or the anatomy component of the fellowship examination. Dr. Kiarash Taghavi, Dr. Simon Richards, and Dr. Omid Yassaie are surgical trainees with the Royal Australasian College of Surgeons (RACS) and have a strong interest and foundation in clinical and surgical anatomy. They have contributed the thorax, abdomen, pelvis and surgical embryology chapters. We would like to thank Professor Spencer Beasley for his supervision in the production of the surgical embryology chapter. Furthermore, We would also like to acknowledge Dr. Jane Zuccollo (Fetal Pathologist) and Louise Goossens (Senior Medical Photographer) for providing the clinical images for the surgical embryology chapter, Robbie Mcphee for the anatomical illustrations, Chris Smith for photographing the specimens, and Shilpan Patel, Sebastien Barfoot, and Joshua Kirkpatrick for assisting with production of the electronic app version (which includes short notes). The short notes are intended as a quick aide-de-memoir that can be read “between patients” or referred to while waiting for surgery. Auckland, New Zealand

S. Ali Mirjalili

v

Contents

1 Upper Limb����������������������������������������������������������������������������������������������    1 S. Ali Mirjalili 2 Lower Limb����������������������������������������������������������������������������������������������   27 S. Ali Mirjalili 3 Thorax������������������������������������������������������������������������������������������������������   57 S. Ali Mirjalili and Kiarash Taghavi 4 Abdomen��������������������������������������������������������������������������������������������������   85 S. Ali Mirjalili and Simon Richards 5 Pelvis��������������������������������������������������������������������������������������������������������   103 S. Ali Mirjalili and Omid Yassaie 6 Head and Neck ����������������������������������������������������������������������������������������  125 S. Ali Mirjalili 7 Surgical Embryology ������������������������������������������������������������������������������  139 Spencer Beasley and Kiarash Taghavi

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1

Upper Limb S. Ali Mirjalili

Part One: Questions Question 1 An elderly lady suffers a fall on her shoulder. Her radiograph shows a fracture (white arrow).

S.A. Mirjalili Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand e-mail: [email protected]

© Springer Nature Singapore Pte Ltd. and People’s Medical Publishing House 2017 S.A. Mirjalili (ed.), Anatomy for the Generic Surgical Sciences Examination (GSSE), DOI 10.1007/978-981-10-3883-9_1

1

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S.A. Mirjalili

1.1 Identify the lateral and medial head of the clavicle. 1.2 Describe the sternoclavicular joint and acromioclavicular joint (type and structure), and their ligaments. 1.3 Name two ligaments providing much of the weight bearing support for the upper limb and their attachments (from lateral to medial). 1.4 Which part of the clavicle is commonly fractured and why?

A B

3

1  Upper Limb

Question 2 Following a motor accident, a young man is unable to move his right arm. His radiograph shows a fracture (white arrow).

2.1 Name structures A, B, C and D. 2.2 What important structure(s) runs behind the label D? What clinical features would be present if the structure(s) was damaged? 2.3 What structure runs between B and C and where does it attach proximally? 2.4 What muscle(s) is attached at the site B and C? 2.5 What muscle(s) is attached at the site E (from lateral to medial)? A

B

C

D E

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S.A. Mirjalili

Question 3 A patient is referred to hospital 2 days after mountain biking accident. His radiograph shows a fracture at the site labeled A on the image. 3.1 What muscle(s) is attached to the label A and what nerve(s) innervates them? 3.2 Name structure B, what muscle(s) is attached around its border and what nerve(s) innervates it? 3.3 Name structures C and D, what muscles attach at these sites and what nerves innervate them? 3.4 What muscle attaches at the site E and what nerves innervate it? 3.5 What muscles attach at the site F and what nerves innervate them?

A B

C

E D

F

Question 4 A young man is playing rugby and is tackled landing on his shoulder tip. His radiograph shows a dislocation of the glenohumeral joint.

1  Upper Limb

5

4.1 Name structures A, B, C and D (X-ray).

C B

D A

4.2 Name structures A, B and C and their innervation?

A D

B

C

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S.A. Mirjalili

4.3 Name D, what is its function and what structure(s) connect to it? 4.4 What features maintain the stability of the shoulder joint? 4.5 Name the rotator cuff muscles and describe their innervations, attachments, and function? 4.6 What type of the dislocation of the glenohumeral joint is most common and why?

Question 5 A newborn suffers shoulder dystocia during delivery and consequent brachial plexus injury. Following the injury the newborn is not flexing his arm. 5.1 Which part of the brachial plexus is held by the forceps? What nerve root(s) is likely to be damaged following this injury?

Sup Med

Lat Inf

le

vic

Cla

E

A

D

C B

5.2 Name structures A, B, C, D and E?

1  Upper Limb

7

5.3 What sensory disturbances may you see in this injury? 5.4 Describe the different parts of the brachial plexus, their branches and their surface markings. 5.5 Describe the axillary artery; its beginning and termination, parts and branches. 5.6 Describe the course of the musculocutaneous nerve and what structure(s) is innervated by musculocutaneous nerve?

Question 6 A university student is referred to the orthopedic outpatient clinic with weak abduction and flexion of the shoulder together with a small sensory loss over his lateral upper arm. 6.1 Name structures A, B, C, D, E, F, G, H and I. G E F

D

B

1

C

2

A

I

Posterior view

Anterior view

6.2 Name gateways 1 and 2 and what structure(s) runs through each? 6.3 What are the borders of the gateways from the anterior and posterior views? 6.4 Describe the course of the radial nerve and axillary nerve in the arm. 6.5 What does the radial nerve supply in the arm? 6.6 What is the function of the axillary nerve?

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Question 7 A young man is referred to the emergency department after being stabbed in the lower third of his anterior arm. 7.1 Name structures A, B and C. 7.2 What are the distal attachments of biceps brachii? 7.3 Explain the course of the median nerve in the arm.

A

C

B

Question 8 A 45 years old woman suffers an iatrogenic injury after having a venous puncture performed. 8.1 Name structures A, B, C and D. 8.2 Describe the borders of the cubital fossa. 8.3 Which structures lie in the roof of the cubital fossa? 8.4 Name the contents of the cubital fossa (from lateral to medial). 8.5 What muscle(s) form the floor of the cubital fossa? C B A

D

1  Upper Limb

9

Question 9 A patient is referred because of weak flexion of the wrist, sensory loss of the medial side of his hand (one and half fingers) and weakness of the muscle of the intrinsic muscles of the hand following a medial epicondyle fracture. I.   Name the structures A, B, C, D, E, F and G. II.  What muscle(s) attaches to the medial and lateral epicondyle? III. Describe the attachment of supinator, flexor carpi ulnaris and pronator teres. IV. What important structure(s) runs through supinator, flexor carpi ulnaris and pronator teres? V.  Describe the muscles of the anterior compartment of the forearm and their innervation. A B C

D E

G

F

Question 10 A 3 year-old girl presents to the emergency department because she is not able to supinate or pronate her forearm. This occured after she was pulled up by her hand. 10.1 Name structures A, B, C, D and E. 10.2 Describe the attachment of the annular ligament. 10.3 Describe the attachment of the lateral and medial collateral ligaments. 10.4 What muscles attach to the radial and ulnar tuberosity?

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S.A. Mirjalili B C

A

E

D

Question 11 A factory worker is referred to the emergency department after an accident that cut the posterior and distal aspects of his forearm. On examination, he was not able to extend his fingers. 11.1 Name structures A, B, C and D. 11.2 Describe the muscles of the extensor compartment and their innervation. 11.3 Describe the extensor retinaculum and its compartments. C A

D B

Question 12 A factory worker is seen in the emergency department after an accident, which cut the dorsal side of his thumb (over the snuff box). On examination, he has some sensory loss distal to the cut. 12.1 Name structures A, B, C, D, E, F, G and H. 12.2 What tendons form the snuffbox (its borders) and what are the contents of the snuffbox? 12.3 What are the distal attachments of the extensors (longus and brevis) and abductor of the thumb?

1  Upper Limb

11

C A

H

B

G

D F

E

Question 13 A tennis player is referred to the orthopedic outpatient clinic because of recurrent pain over the lateral side of his elbow. 13.1 Name structures A and B. 13.2 Describe the course of the radial nerve in the forearm and its branches. 13.3 What structure(s) is innervated by the radial nerve in the forearm (sensory, muscular)? 13.4 Describe the course of the ulnar nerve in the forearm and its branches. 13.5 What structure(s) is innervated by the ulnar nerve in the forearm (sensory, muscular)? 13.6 Describe the course of the median nerve in the forearm and its branches. 13.7 What structure(s) is innervated by the median nerve in the forearm (sensory, muscular)?

A B

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Question 14 A young man is brought to the emergency department after a fight in the pub. He has suffered a laceration over his anterior wrist from sharp glass between the proximal and distal crease. 14.1 Name the structure shown by the probe. 14.2 Name structures A, B, C, D and E. B

A

C

E

D

Question 15 A patient suffers a large hematoma after having an arterial-blood gas done by a house-officer on the ward. 15.1 Name structures A, B, C and D. 15.2 Describe the course of the radial artery and its branches in the forearm and hand. 15.3 Describe the course of the ulnar artery and its branches in the forearm and hand. A

B

C

D

Question 16 A skier requires emergency treatment after he falls on the palm on an outstretched hand. On examination, she feels pain and tenderness in the snuffbox.

1  Upper Limb

13

16.1 Name structures A, B, C and D.

D

B

C A

16.2 Name the first and second rows of the wrist bones from lateral to medial. 16.3  What muscle(s) attaches to the first metacarpal, proximal and distal phalanges? 16.4 Describe the attachments of the adductor of the thumb, its innervation and what structure runs through it.

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Question 17 A farmer is referred to a neurologist because of poor grip and wasting of the thenar muscles. 17.1 Name structures A and B. 17.2 What structures run in the carpal tunnel? 17.3 What tendon runs through the flexor retinaculum? 17.4 Describe why this patient has spared sensation at the medial side of the base of his hand despite a suspected median nerve neuropa

A

B

hty.

Question 18 A patient presents to the emergency department after cutting the proximal part of his index finger. After examination, she has some sensory loss distal to the cut. 18.1 Name structures A, B, C, D and E. 18.2 Describe the sensory and muscular innervation of the hand. 18.3 Describe the attachments, function and innervation of the palmar and dorsal interossei. 18.4 Describe the attachments, function and innervation of the lumbricals. C

B

E D

A

1  Upper Limb

15

Part Two: Answers Question 1 1.1 The acromial end (lateral) is flat (A) whereas the sternal (medial) end is more robust (quadrangular shape) (B). 1.2 Sternoclavicular joint is an atypical synovial joint with features of a ball and socket and is separated into two cavities by a cartilaginous disc. Acromioclavicular joint is an atypical synovial joint between the overhanging lateral end of the clavicle and the under-hanging medial border of the scapula. It is surrounded by a sleeve like capsule. 1.3 Trapezoid (lateral) and conoid (medial). 1.4 The clavicle is most commonly fractured at the junction between the middle and lateral thirds. This is because of (1) the strong coracoclavicular ligament laterally holding the lateral third and (2) the lateral third is flatter whilst the medial two thirds are circular in cross-section. Question 2 2.1 A: Anatomical neck, B: Lesser tubercle, C: Greater tubercle, D: Surgical neck. 2.2 Posterior humeral circumflex artery (haematoma) and axillary nerve (sensory loss over a small part of the lateral upper arm). 2.3 Tendon of the long head of the biceps brachii. It attaches to the superior glenoid tubercle. 2.4 Subscapular (B) and supraspinatus, infraspinatus and teres minor (C). 2.5 Pectoralis major, latissimus dorsi and teres major (“Lady between Two Majors”). Question 3 3.1 Pectoralis minor (medial pectoral nerve), coracobrachialis (musculocutaneous nerve) and short head of biceps brachii (musculocutaneous nerve). 3.2 B = Acromion, Trapezius (spinal accessory nerve) and deltoid (axillary nerve). 3.3 C = Supraglenoid tubercle, D = Infraglenoid tubercle, tendon of the long head of the biceps brachii (musculocutaneous nerve) is attached to C and tendon of the long head of the triceps brachii (radial nerve) to D. 3.4 Subscapularis (upper and lower subscapular nerves). 3.5 Teres major (lower subscapular nerve) and serratus anterior (long thoracic nerve). Question 4 4.1 A: Head of humerus, B: Coracoid process, C: Clavicle and D: Glenoid cavity. 4.2 A: Pectoralis minor, B: Subscapularis, C: Long head of triceps brachii. 4.3 D: Glenoid labrum. The glenoid labrum (fibrocartilage ring) deepens the fossa and stabilises the joint. The long head of biceps brachii attaches to it. 4.4 Articular surface, glenohumeral ligaments, joint capsule, rotator cuff muscles, long head of biceps and triceps and negative intra-articular pressure. 4.5 Rotator cuff muscles provide dynamic stability and include: the supraspinatus, infraspinatus, teres minor and subscapularis. Their tendons fuse with lateral part of the joint capsule.

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4.6 The most common dislocation is anterior dislocation which typically occurs when the arm is abducted and externally rotated. The joint is least stable inferiorly when the shoulder is abducted. Question 5 5.1 Lateral cord (C5, 6 and 7). 5.2 A: Musculocutaneous nerve, B: Median nerve, C: Ulnar nerve, D: Coracobrachialis muscle, E: Axillary artery. 5.3 Loss of sensation in the lateral side of the forearm and also of the 1 and ½ dorsal and palmar sides of the hand medially. 5.4 Brachial plexus is described as below: Surface anatomy Posterior triangle Roots Trunks C5 Superior C6 C7 Middle C8 T1

2nd part of axillary (posterior to pectoralis minor) Terminal branches Musculocutaneous & Median Radial & Axillary

(posterior to subclavian artery)On 1st rib Divisions Cords Anterior branch of S Lateral (C5, 6, 7) &M Posterior branch of S, M & I Anterior branch of I

Inferior

Posterior (C5-T1) Medial (C8, T1)

Ulnar & Median

S Superior, M Middle, I Inferior, A Anterior, P Posterior, C Cervical, T Thoracic. 5

A

1

4

C5 *

B

C6 2**

C

C7 D 9

10

11 C8

E

T1 6

7

8 3

* Contribution to phrenic nerve (C3, 4, 5); ** Nerve to subclavius reportedoriginates from the root or from the trunk.

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• Branches from the roots (Supraclavicular part) –– Dorsal scapular nerve C5 (passes behind the rhomboids) (1) –– Nerve to subclavius C5 & C6 (passes in front of the subclavius) (2) –– Long thoracic nerve C5, C6 & C7 (passes behind the serratus anterior) (3) • Branches from the trunks –– Suprascapular nerve (4) • Branches from the lateral cord –– Lateral pectoral (innervates pectoralis major together with medial pectoral nerve) (5) –– Musculocutaneous perforates the coracobrachialis (innervates coracobrachialis, biceps brachii, brachialis and ends as lateral cutaneous nerve of the forearm) (A) –– Lateral contribution of median nerve (C) • Branches from the medial cord –– Medial pectoral arises behind the axillary artery (deep surface of pectoralis minor then pectoralis major) (6) –– Medial contribution of the median nerve (C) –– Medial cutaneous nerve of the arm (runs down on the axillary vein and gives sensory to the medial arm skin) (7) –– Medial cutaneous nerve of the forearm (runs between artery and vein and gives sensory to the medial forearm skin) (8) –– Ulnar nerve (runs between artery and vein behind medial cutaneous nerve of the forearm) (E) • Branches from the posterior cord –– Upper subscapular (small nerve to subscapularis) (9) –– Thoracodorsal (large nerve to latissimus dorsi) (10) –– Lower subscapular (supplying the lower part of subscapular muscle and teres major) (11) –– Axillary nerve (passes backwards through quadrangular space, behind the surgical neck of the humerus and innervates the deltoid, teres minor and gives sensory to a small patch on the lateral side of the upper arm) (B) –– Radial nerve (largest branch and passes down through the triangular space into the radial groove between the lateral and medial heads of the triceps) (D)

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5.5 The subclavian artery becomes the axillary artery at the lateral border of the 1st rib and the axillary artery becomes the brachial artery at the lower border of teres major. It is divided into three parts by pectoralis minor (above, behind and below). Its branches: 1st part one branch (Superior thoracic artery), 2nd part two branches (Thoracoacromial artery and lateral thoracic artery) and 3rd part three branches (subscapular artery, anterior and posterior circumflex humeral artery). C5 C6 C7 C8 T1 2nd part of axillary artery

5.6 Musculocutaneous nerve perforates coracobrachialis, runs between biceps brachii and brachialis and terminates as the lateral cutaneous nerve of the forearm (innervates coracobrachialis, biceps brachii, brachialis and ends as the lateral cutaneous nerve of the forearm). Question 6 6.1 A: Latissimus dorsi, B: Triceps brachii (its long head), C: Teres major, D: Subscapularis, E: Infraspinatus, F: Teres minor, G: Supraspinatus, H: Pectoralis minor, I: Brachialis. 6.2 Quadrangular space transmits the axillary nerve, posterior circumflex humeral artery and veins which lie inferiorly. Triangular space transmits the radial nerve and profunda brachii vessels. 6.3 Quadrangular space lies between subscapularis, teres major, humerus and long head of triceps (anterior view) and teres major, teres minor, humerus and long head of triceps (posterior view). Triangular space lies below teres major between the humerus and long head of triceps. 6.4 Axillary nerve passes backwards through the quadrangular space, behind the surgical neck of the humerus. Radial nerve passes down through the triangular

1  Upper Limb

19

space into the radial groove between the lateral and medial heads of triceps brachii. 6.5 Radial nerve innervates the triceps brachii muscle. 6.6 Axillary nerve innervates deltoid, teres minor and gives sensory supply to a small patch on the lateral upper arm (Regimental patch). Question 7 7.1 A: Median nerve, B: Biceps brachii, C: Brachial artery. 7.2 The tendon of the biceps brachii attaches distally to the radial tuberosity and its bicipital aponeurosis to the deep fascia. 7.3 The median nerve is formed at the lower border of the axilla by union of the contribution of the medial and lateral cords and then runs between the biceps brachii and brachialis along its course. The nerve lies in front of the brachial artery crossing from lateral to medial in the cubital fossa. Question 8 8.1 A: Pronator teres, B: Bicipital aponeurosis, C: Median nerve, D: Brachioradialis. 8.2 Brachioradialis muscle, pronator teres and an imaginary horizontal line between the medial and lateral epicondyles. 8.3 Superficial fascia, the lateral and medial cutaneous nerve of the forearm and the median cubital vein. 8.4 Tendon of the biceps brachii muscle (with its aponeurosis), the brachial artery and median nerve. 8.5 Brachialis muscle. Question 9 9.1 A: Lateral epicondyle, B: Olecranon, C: Trochlea, D: Medial epicondyle, E: Coronoid process, F: Capitulum, G: Radial fossa. 9.2 The medial epicondyle is the major papable landmark on the medial side of the elbow and on its surface it bears a large oval impression for the attachment of muscles in the anterior compartment of the forearm (pronator teres, flexor carpi radialis, flexor digitorum superficialis, palmaris longus and flexor carpi ulnaris). The lateral epicondyle is much less pronounced and has an irregular impression for the attachment of muscles in the posterior compartment of the forearm (brachioradialis, extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, extensor carpi ulnaris and anconeus). 9.3 Pronator teres (humeral head: medial epicondyle, medial supracondylar ridge and medial intermuscular septa and, ulnar head: medial border of coronoid process), flexor carpi ulnaris (humeral head: common flexor origin and, ulnar head: aponeurosis from the medial olecranon and upper 3/4 ulna) and supinator (deep part: from the supinator crest and fossa of the ulna and, superficial part: from the lateral epicondyle and lateral ligament of the elbow and annular ligament).

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9.4 The median nerve passes between the two heads of pronator teres, the ulnar nerve passes between the two heads of the flexor carpi ulnaris, and the radial nerve passes between the two heads of supinator. 9.5 The superficial and deep muscles of the anterior compartment of the forearm are summerised in Table 1.1 and Table 1.2 shown as below.

Table 1.1  Superficial Muscles (5 muscles) Pronator teres

Flexor carpi radialis

Flexor digitorum superficialis

Palmaris longus

Flexor carpi ulnaris

Origin

Insertion

Action

Nerve

Humeral head: medial epicondyle, medial supracondylar ridge and medial intermuscular septa Ulnar head: medial border of coronoid process CFO

Posterior to the most prominent part of lateral convexity of radius

Pronates forearm and flexes elbow

Median nerve (C6, 7)

Bases of 2nd and 3rd MC via groove in trapezium Tendons split to insert onto sides of middle phalanges of medial four fingers

Flexes and abducts wrist

Median nerve (C6, 7)

Flexes proximal IP joint and MCP/wrist

Median nerve (C7, 8, T1)

Flexor retinaculum and palmar aponeurosis Pisiform, hook of hamate, base of fifth MC via pisometacarpal and pisohamate ligaments

Flexes wrist and tenses palmar aponeurosis Flexes and adducts wrist and fixes pisiform during action of hypothenar muscles

Median nerve (C7, 8)

Humeral head: Medial epicondyle of humerus and medial ligament of elbow Ulnar head: sublime tubercle & fibrous arch Radial head: whole length of anterior oblique line Medial epicondyle of humerus

Humeral head: Medial epicondyle of humerus Ulnar head: aponeurosis from medial olecranon and upper ¾ ulna

Ulnar nerve (C7, 8, T1)

Important Median nerve passes between its two heads

Median nerve runs under surface of muscle

Ulnar nerve passes between two head

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1  Upper Limb Table 1.2  Deep Muscles (3 muscles) Flexor digitorum profundus

Flexor pollicis longus

Pronator quadratus

Origin

Insertion

Action

Upper 3/4 of anterior and medial surface of ulna as far around as subcutaneous border and narrow strip of interosseous membrane Anterior surface of radius below anterior oblique line and adjacent interosseous membrane Lower 1/4 of anteromedial shaft of ulna

Distal phalanges of medial four fingers

Flexes distal IP joints then 2° flexes IP and MCP joints and wrist

Base of distal phalanges

Flexes distal IP joint

Median nerve (Anterior interosseous) (C7, 8)

Lower 1/4 of anterolateral shaft of radius and some interosseous membrane

Pronates forearm and maintains radius and ulna opposed

Median nerve (Anterior interosseous) (C7, 8)

Nerve Medial half by ulnar nerve (C8, T1) Lateral half by median nerve (Anterior interosseous)

CFO Common Flexor Origin, MC Metacarpal, MCP Metacarpophalangeal, IP Interphalangeal

Question 10 10.1 A: Tendon of biceps brachii, B: Lateral collateral ligament, C: Radial tuberosity, D: Medial collateral ligament, E: Interosseous membrane. 10.2 Annular ligament is attached to the margins of the radial notch of the ulna and slings around the head and neck of the radius. 10.3 Ulnar collateral (medial collateral) ligament is triangular. (1-Anterior band – passes from medial epicondyle of humerus, 2- Posterior band – from medial border of olecranon, 3- Middle band – connects anterior and posterior bands and lodges the ulnar nerve.) Radial collateral (lateral collateral) ligament is a single flattened band from below the common extensor origin to the annular ligament. 10.4 The tendon of the biceps brachii attaches to the radial tuberosity of the radius. The tendon of the brachialis attaches to the ulnar tuberosity of the ulnar. Question 11 11.1 A: Abductor pollicis longus, B: Extensor retinaculum, C: Superficial branch of the radial nerve, D: Extensor digitorum. 11.2 The superficial and deep muscles of the posterior compartment of the forearms are summerised in Table 1.3 and Table 1.4 shown as below.

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Table 1.3  Superficial muscles (7 muscles) Origin

Insertion

Action

Brachioradialis

Upper 2/3 of lateral supracondylar ridge of humerus and lateral intermuscular septa

Base of styloid process of radius

Extensor carpi radialis longus

Lower 2/3 lateral supracondylar ridge of humerus and lateral intermuscular septa

Posterior base of 2nd MC

Flexes arm at the elbow and brings the forearm into the mid-prone position Extends and adducts the hand at the wrist

Extensor carpi radialis brevis

CEO

Posterior base of the 2nd MC

Extensor digitorum

CEO

Extensor digiti minimi

CEO

Extensor carpi ulnaris

CEO and aponeurotic sheath from the ulna

Extensor expansion of all four fingers, 3 and 4 normally fuse with five only getting a slip Extensor expansion of the little finger, usually two tendons which are joined by extensor digitorum Base of 5th MC via groove by ulnar styloid

Anconeus

Smooth surface at the lower extremity of posterior aspect of lateral epicondyle of humerus

Lateral side of the olecranon

Extends and adducts the hand at the wrist Extends all joints of fingers

Nerve Radial nerve (before division into superficial and deep)

Radial nerve (before division into superficial and deep) Radial nerve (deep branch)

Radial nerve (posterior interosseous nerve)

Extends all joints of the little finger

Radial nerve (posterior interosseous nerve)

Extends and adducts the hand at the wrist Weak extensor of the elbow

Radial nerve (posterior interosseous nerve) Radial nerve (via branch to medial head of triceps brachii)

11.3 Extensor retinaculum; • Ribbon like band (2.5 cm wide) lying obliquely across the extensor surface of the wrist joint. • Proximally is attached to the radius above the styloid process and distally attached to pisiform and triquetral bones. • Not attached to the ulna. • Is a thickening of the deep fascia of the forearm.

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1  Upper Limb Table 1.4  Deep muscles (5 muscles) Supinator

Abductor pollicis longus

Extensor pollicis brevis

Extensor pollicis longus

Extensor indicis

Origin

Insertion

Action

Nerve

Deep part from the supinator crest and fossa of the ulna Superficial part from the lateral epicondyle and lateral ligament of the elbow and annular ligament Upper posterior surface of the ulna and middle 1/3 of the posterior surface of the radius and interosseous membrane Lower 1/3 posterior shaft of radius and interosseous membrane

Neck and shaft of the radius

Supinate the forearm and only acts alone when the elbow is extended

Radial nerve (posterior interosseous nerve)

Important Radial nerve passes between its two heads

Over tendons of radial extensors and brachioradialis to base of 1st MC and trapezium

Abducts and extends thumb at the CMC joint

Radial nerve (posterior interosseous nerve)

Forms the radial side of the snuff box

Over tendons of radial extensors and brachioradialis to base of the proximal phalanx of thumb Base of distal phalanx of thumb

Extends MPC joint of the thumb

Radial nerve (posterior interosseous nerve)

Forms the radial side of the snuff box

Extends IP and MCP joints of thumb Extends all joints of the index finger

Radial nerve (posterior interosseous nerve)

Forms ulnar side of snuff box

Middle 1/3 of posterior ulna and interosseous membrane Lower posterior shaft of the ulna and interosseous membrane

Extensor expansion of the index finger

Radial nerve (posterior interosseous nerve)

CEO Common Extensor Origin, MC Metacarpal, MCP Metacarpophalangeal, IP Interphalangeal, CMC Carpometacarpal

• Maintains a constant tension throughout pronation/supination and holds down the extensor tendons. • From the extensor retinaculum, fibrous septa pass to the bones of the forearm with the extensor tunnel and divide into 6 compartments: 1- abductor pollicis longus, 2- extensor pollicis brevis, 3- extensor pollicis longus, 4- extensor digitorum and extensor indicis, 5- extensor minimi digiti and 6- extensor carpi ulnaris.

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Question 12 12.1 A: Radial artery, B: The deep palmar branch of the radial artery, C: The superficial palmar branch of the radial artery, D: Abductor pollicis longus, E: Extensor pollicis brevis, F: Extensor pollicis longus, G: Superficial branch of the radial nerve, H: First dorsal interosseous. 12.2 Anatomical snuffbox. The anatomical snuff box is a concavity between the extensor pollicis longus (ulnar side) and, extensor pollicis brevis/ abductor pollicis longus (radial side). • Cutaneous branch of the radial nerve (superficial division) crosses over these tendons. • Cephalic vein begins in the box. • Radial artery lies deep to all three tendons. • Floor (proximal to distal); radial styloid, scaphoid, trapezium and base of the 1st metacarpal bone. 12.3 The distal atachment of the extensor pollicis longus is to the base of the 1st distal phalanx, the extensor pollicis brevis to the base of the 1st proximal phalanx and the abductor pollicis longus to the base of 1st metacarpal bone and trapezium. Question 13 13.1 A: Radial nerve, B: Brachioradialis. 13.2 The radial nerve passes through the two heads of the supinator muscle, divides into superficial and deep branches of the radial nerve and these then appear in the extensor compartment. The deep branch runs in the extensor (posterior) compartment of the forearm and it continues as the posterior interosseous nerve. The superficial branch runs under brachioradialis and then over abductor pollicis longus, extensor pollicis longus and extensor pollicis brevis at the distal end of the forearm to reach the lateral side of the dorsum of the hand. 13.3 Radial nerve supplies all muscles of the extensor compartment: brachioradialis, extensor carpi radialis longus, the muscles arising from the common extensor origin, deep muscles of the extensor compartment and sensory to interosseous membrane and periosteum. It has no cutaneous branch in the forearm. 13.4 The ulnar nerve enters the forearm by passing between the two heads of flexor carpi ulnaris and lies under flexor carpi ulnaris along its course in the forearm and does not till the wrist. It passes over the flexor retinaculum and supplies skin over the hypothenar eminence (palmar branch) as well as 1½ fingers (palmar side) and it also gives off a dorsal branch at the distal end of the forearm to innervates the dorsum of the hand and ulnar 1½ fingers. 13.5 The ulnar nerve supplies flexor carpi ulnaris and the medial half of flexor digitorum profundus and has no cutaneous branch in the forearm. 13.6 From the cubital fossa, the median nerve runs between the two heads of pronator teres and then runs between flexor digitorum superficialis and flexor digitorum profundus. At the distal end of the forearm, it runs superficially between the tendons of flexor carpi radialis and palmaris longus before it continues

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through the carpal tunnel under the flexor retinaculum. Before the flexor ­retinaculum, the median nerve gives a palmar branch which crosses the wrist over the flexor retinaculum. 13.7 The median nerve supplies all the muscles of the forearm (except flexor carpi ulnaris and the medial half of flexor digitorum profundus), the interosseous membrane and periosteum. It has no cutaneous branch in the forearm. Question 14 14.1 Median nerve. 14.2 A: Flexor digitorum superficialis, B: Flexor carpi ulnaris, C: Flexor carpi radialis, D: Brachioradialis, E: Palmaris longus. Question 15 15.1 A: Superficial palmar branch (of the ulnar artery), B: Carpal tunnel, C: Ulnar artery, D: Radial artery. 15.2 The radial artery passes distally medial to the biceps tendon, across supinator, over the insertion of pronator teres, the radial origin of flexor digitorum superficialis, the origin of flexor pollicis longus, the insertion of pronator quadratus and the lower end of the radius. At the distal forearm it divides into the superficial and deep palmar branches and the deep palmar branch passes deep to the tendons of abductor pollicis longus/extensor pollicis brevis to enter the snuff box. • In the upper part of the forearm it is overlapped by brachioradialis. • In the middle third of the forearm it has the radial nerve lateral to it. Surface marking: along a line (slightly convex laterally), from medial side of the biceps tendon in the cubital fossa to the styloid process of the radius. 15.3 From the cubital fossa, it passes deep to pronator teres and flexor digitorum superficialis near the median nerve, then lies on flexor digitorum profundus. The ulnar nerve lies medial to it. Surface marking: from medially at the biceps brachii tendon to the radial side of the pisiform. Question 16 16.1 A: Scaphoid, B: Hook of hamate, C: 1st metacarpal, D: 1st proximal phalanx. 16.2 Proximal row (lateral to medial): scaphoid, lunate, triquetrum and pisiform. Distal row (lateral to medial): trapezium, trapezoid, capitate and hamate. 16.3 Metacarpal I: abductor pollicis longus and opponens pollicis. Proximal phalanx: 1st palmar interosseous, adductor pollicis, abductor pollicis brevis, flexor pollicis brevis and extensor pollicis brevis. Distal phalanx: extensor pollicis longus and flexor pollicis longus. 16.4 Origin: Transverse head: metacarpal III and oblique head: capitate and bases of the metacarpals II and III. Insertion: base of the proximal phalanx and extensor hood of the thumb. Innervation: ulnar nerve (palmar branch).

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The deep palmar arch runs between the oblique and transverse heads of adductor pollicis. Question 17 17.1 A: Palmar aponeurosis, B: Thenar muscles. 17.2 NINE tendons and ONE nerve in total; flexor digitorum superficialis (four tendons), flexor digitorum profundus (four tendons), flexor pollicis longus (one tendon) and the median nerve. 17.3 Flexor carpi radialis runs through the flexor retinaculum. 17.4 Palmar (cutaneous) branch of the median nerve runs over the flexor retinaculum. Question 18 18.1 A: Ulnar nerve, B: Hypothenar muscles, C: Digital nerve (median branch), D: Flexor digitorum superficialis, E: Flexor digitorum profundus. 18.2 All muscles of the hand are innervated by the ulnar nerve EXCEPT the thenar muscles and two lateral lumbricals. Dorsum of the hand; cutaneous innervation is by radial nerve (3½ ) and ulnar nerve (1½) with the distal phalanges supplied by the median and superficial ulnar nerves. Palm of the hand; cutaneous innervation is by superficial (palmar) branches of the ulnar nerve and the median nerve (digital and palmer branches) with the radial nerve over the thenar eminence. 18.3 Palmar interossei are smaller and arise from their own metacarpal bone, these muscles adduct toward the middle finger (which has no adductor). Dorsal interossei are larger and arise from the adjacent sides of the metacarpal bone of the space in which they lie. These muscles abduct and are more powerful. There is no distal attachment to the 1st and 5th proximal phalanges and there is one on each side of 3rd proximal phalanx. • Action: palmer interossei adduct towards the middle finger (PAD) and the dorsal interossei abduct (DAB). • All supplied by the palmar (deep) branch of the ulnar nerve. 18.4 Lumbricals originate from the tendons of flexor digitorum profundus and insert into the extensor hoods of the index, ring, middle and little fingers. The medial two are innervated by the ulnar nerve (palmar branch) and the lateral lumbricals by the median nerve (digital branch). • Action: Flex the metacarpophalangeal joints while extending the interphalangeal joints.

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Lower Limb S. Ali Mirjalili

Part One: Questions Question 1 Three weeks after a minor motor vehicle accident a young woman presents to hospital with radicular pain and tingling in her buttocks. She is diagnosed with piriformis syndrome.

F E

C A

D B

1.1 Name structures A, B, C, D, E and F. 1.2 Describe what neurovascular structures emerge from the pelvis above and below piriformis. 1.3 What are the nerve roots of the inferior and superior gluteal nerves, sciatic nerve and pudendal nerve? 1.4 What forms the boundaries of the lesser and greater sciatic foraminae? 1.5 Which structures run through the lesser sciatic foramen? S.A. Mirjalili Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand e-mail: [email protected] © Springer Nature Singapore Pte Ltd. and People’s Medical Publishing House 2017 S.A. Mirjalili (ed.), Anatomy for the Generic Surgical Sciences Examination (GSSE), DOI 10.1007/978-981-10-3883-9_2

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Question 2 A patient is referred to hospital after a motor vehicle accident. His trauma series pelvic x-ray is shown below.

2.1 Name structures A, B, C, D, E and F. 2.2 Name the intrinsic and extrinsic ligaments of the hip joint together with their position? 2.3 What are the anterior, posterior, superior and inferior relations of the hip joint? 2.4 What is the blood supply and lymphatic drainage of the hip joint? 2.5 What is the nerve supply of the hip joint? E F

B

D

C A

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Question 3 A patient is referred to the on-call surgical team with a hematoma on the anterior aspect of the thigh following a percutaneous coronary procedure.

B

A

C D

E

3.1 Name structures A, B, C, D and E. 3.2 What forms the borders, floor and roof of the femoral triangle? 3.3 What are the contents of the femoral triangle (lateral to medial)? 3.4 What forms the femoral sheath and what are its contents? 3.5 What is the adductor canal, its boundaries and its contents?

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Question 4 An elderly man presents for vascular work-up. Femoral artery angiography was performed below the inguinal ligament and is demonstrated below.

4.1 Name structures A, B and C. 4.2 Describe the course of the femoral artery and its branches. 4.3 Name the two arterial anastomotic networks around the hip. Which one is the most important and where are their sites? 4.4 Describe the saphenofemoral junction and its tributaries.

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4.5 Describe the course of the femoral nerve above and below the inguinal ligament and the structures innervated by the femoral nerve. 4.6 What is the surface marking of the femoral artery?

A

C B

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Question 5 A middle-aged man was admitted following myocardial infarction and was planned for coronary bypass surgery. After his operation he complains of a burning sensation over the lateral aspect of his leg.

D

C

E

A B

F

5.1 Name structures A, B, C, D, E and F. 5.2 What nerve was damaged? Describe its course and origin. 5.3 What is the course of the small saphenous vein? 5.4 What is the course and origin of the saphenous nerve? 5.5 What is the course of the great saphenous vein and what nerve accompanies the vein? 5.6 What is the surface marking of the saphenofemoral junction?

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Question 6 A patient is seen in the orthopedic outpatient clinic with a muscular mass of the medial thigh thought to be a sarcoma.

B

A

C D E

6.1 Name structures A, B, C, D and E. 6.2 Describe the medial compartment of the thigh and its innervation. 6.3 What are the nerve roots of the obturator nerve? Describe its course in the medial compartment of the thigh. 6.4 What is the blood supply of the medial compartment of the thigh?

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Question 7 On the ward round an elderly lady is found to have weak extension of the hip and leg with sensory loss over her lateral leg following a gluteal intramuscular injection.

D

A C

B

7.1 Name structures A, B, C and D. 7.2 Describe the boundaries of the posterior compartment of the thigh and the components of the hamstrings, their attachments and innervation. 7.3 Where does the posterior compartment of the thigh derive its innervation and blood supply?

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Question 8 A young man presents to the emergency department after suffering a penetrating injury to his posterior knee following a motorbike accident. Examination reveals a foot drop.

B

A E

C

F

H

G

I D

8.1 Name structures A, B, C, D, E, F, G, H and I. 8.2 What are the boundaries, floor and roof of the popliteal fossa? 8.3 What are the contents of the popliteal fossa? 8.4 Describe the course of the middle genicular artery. 8.5 What are the functions of the popliteus muscle?

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Question 9 A rugby player is taken out of the game after being tackled. He is limping with pain in his knee. Examination shows a positive anterior draw test and his radiograph is shown below. L

9.1 What injury did he suffer? 9.2 Name structures A and B and, what structures attach to C, D and E? 9.3 What are the attachments of the anterior and posterior cruciate ligament? 9.4 What are the differences between the lateral and medial menisci? 9.5 What is the blood supply, lymphatic drainage and innervation of the knee? B

C

E

A

D

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Question 10 A young man is brought to the emergency department after suffering a deep circumferential burn around his leg. He has severe pain and sensory disturbance in his foot.

A C

B D

10.1 What is the possible diagnosis? 10.2 Name the structures A, B, C and D. 10.3 Describe the boundaries and muscles of the anterior and lateral compartments of the leg. 10.4 Describe the blood supply and innervation of the lateral and medial compartments of the leg. 10.5 Describe the attachments of the extensor retinacula.

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Question 11 A 75 year-old man presents to the emergency department following strenuous exercise. Examination shows a palpable gap in his Achilles tendon. When squeezing the calf with the patient lying prone no plantar flexion is observed.

B

A

C

11.1 Name structures A, B and C. 11.2 Describe the blood supply and innervation of the posterior compartment of the leg. 11.3 Which muscles are superficial and deep to the neurovascular bundle in the posterior compartment of the leg? 11.4 Describe the sensory innervation of the leg.

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Question 12 A factory worker is brought to the emergency department after an accident that resulted in a deep laceration posterior to his medial malleolus. On examination he is not able to invert his foot.

B A

C

12.1 Name structures A, B and C. 12.2 What muscle is likely to be damaged? 12.3 Describe the tarsal tunnel and its contents (from anterior to posterior). 12.4 Describe the attachments of the flexor retinaculum.

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Question 13 A young man is seen in the emergency department following a motorbike accident. He has swelling and tenderness over his ankle. Plain ankle radiograph demonstrates a distal fibula fracture.

B

A

C

13.1 Name structures A, B and C. 13.2 What ligament is likely to be damaged? 13.3 Describe the medial and lateral ligaments of the ankle. 13.4 What is the blood supply and innervation of the ankle? 13.5 Name the structures that pass over the ankle anteriorly.

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Question 14 A young man is brought to the emergency department after falling from a height onto his foot. His radiograph shows a fractured calcaneus (Lover’s fracture).

14.1 Name structures A, B, C, D, E and F. 14.2 Describe the subtalar joint and what stabilises it. 14.3 Describe the talocalcaneonavicular joint and what stabilises it. 14.4 Describe the calcaneocuboid joint and what strengthens it. 14.5 Describe the arches of the foot.

E

D

C

B

A F

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Question 15 A patient presents to the emergency department after injuring the sole of her foot. On examination she has sensory loss distal to the laceration with pulsatile bleeding.

B

A

15.1 Name structures A and B. 15.2 Describe the layers of the foot. 15.3 What is the course of the medial and lateral plantar nerves and what structures are innervated by them? 15.4 Which muscles are most likely to be injured?

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Question 16 A patient presents to the emergency department after sustaining a laceration to the dorsum of his foot. On examination he has sensory loss over the dorsal aspect of the foot sparing the first web space.

C

B

A

16.1 Name structures A, B and C. 16.2 What nerve is likely to be damaged? 16.3 What nerve innervates the first web? 16.4 What structures are present on the dorsum of the foot? 16.5 What is the surface marking for palpation of dorsalis pedis?

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Part Two: Answers Question 1 1.1 A: Sacrospinous ligament, B: Sacrotuberous ligament, C: Greater sciatic notch, D: Lesser sciatic notch, E: Sciatic nerve, F: Piriformis muscle. 1.2 Emerging from the pelvis through the greater sciatic foramen above the upper border of piriformis are the: superior gluteal nerve and vessels. Emerging from the pelvis through the greater sciatic foramen below the lower border of piriformis are the: 1- inferior gluteal nerve and vessels, 2- sciatic nerve, 3- posterior cutaneous nerve of the thigh, 4- pudendal nerve and internal pudendal vessels, 5- nerve to obturator internus, 6- nerve to quadratus femoris. 1.3 Superior gluteal nerve (L4, 5, S1) Inferior gluteal nerve (L5, S1, 2) Sciatic nerve (L4, 5, S1, 2, 3) Pudendal nerve (S2, 3, 4) 1.4 The greater sciatic foramen is bounded superiorly and anteriorly by the greater sciatic notch of the hip bone, posteriorly by the sacrotuberous ligament, and inferiorly by the sacrospinous ligament and ischial spine. The lesser sciatic foramen is bounded anteriorly by the lesser sciatic notch of the hip bone, posteriorly by the sacrotuberous ligament, and superiorly by the ischial spine and sacrospinous ligament. 1.5 It transmits the tendon of obturator internus together with the nerve to obturator internus, the pudendal nerve and internal pudendal vessels. Question 2 2.1 A: Obturator membrane, B: Acetabular labrum, C: Ligament of head of femur (ligamentum teres/foveal ligament), D: Lesser trochanter, E: Greater trochanter, F: Neck of the femur. 2.2 Ligaments of the hip joints include: Two intrinsic ligaments of the hip joint, the ligament of the head of the femur (runs between the head of the femur and the acetabulum) and the transverse acetabular ligament (crosses the acetabular notch). Three extrinsic ligaments (which reinforce the fibrous capsule), the iliofemoral ligament lies anterosuperiorly, the pubofemoral ligament inferiorly and the ischiofemoral ligament posteriorly. Each of which arises from a separate component of the hip bone and blends with the joint capsule and spiral around the femoral neck. 2.3 Anteriorly from medial to lateral: pectineus and the overlying femoral vein, the tendon of psoas major and the overlying femoral artery, iliacus with the femoral nerve in the groove between it and the tendon of psoas major, and the straight head of rectus femoris together with the deep layer of the iliotibial tract fascia. Superiorly from medial to lateral: the reflected head of rectus femoris and gluteus minimus. Inferiorly: obturator externus.

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Posteriorly from above downwards: piriformis, the tendon of obturator internus with the gemelli separating the joint from the sciatic nerve, the tendon of obturator externus and an ascending branch of the medial circumflex femoral artery separating the joint from quadratus femoris and the sciatic nerve. 2.4 The hip joint receives an arterial supply from several sources: 1. The trochanteric anastomosis (which supplies the head and intracapsular part of the neck of the femur), 2. A small arterial branch (which usually originates from the obturator artery, runs through the ligament of the head of the femur and is more important in young children than adults because it supplies the epiphysis) and 3. A relatively minor intramedullary supply after osseous union of the femoral head and neck (which is complete in both sexes by 18 years). Lymphatics drain to the inguinal and internal iliac lymph nodes. 2.5 The anterior capsule of the hip joint is innervated by the femoral and obturator nerves and the posterior capsule by the sciatic and superior gluteal nerves, and nerve to quadratus femoris. Question 3 3.1 A: Femoral nerve, B: Inguinal ligament, C: Femoral artery, D: Adductor longus muscle, E: Sartorius muscle. 3.2 Femoral triangle is an inverted triangle and its boundaries are: The base is the inguinal ligament. The lateral border is the medial border of sartorius. The medial border is the medial border of adductor longus. The apex is the point where sartorius overlaps adductor longus. The floor is formed by the following muscles (medial to lateral): adductor longus, small portion of the adductor brevis, pectineus, psoas major, and iliacus. The roof is formed by fascia lata, subcutaneous tissue and skin. 3.3 The contents (lateral to medial) are: femoral nerve, femoral artery, femoral vein (receiving the great saphenous vein), and femoral canal containing lymphatics. 3.4 Femoral sheath is formed by the transversalis fascia anteriorly and the iliacus fascia posteriorly, which both fuse with the adventitia of the femoral vessels a few centimeters distal to the inguinal ligament. There are three compartments within the femoral sheath: Lateral – contains the femoral artery, Intermediate – contains the femoral vein, Medial (the femoral canal) contains fat, lymph node(s) and lymphatics. The femoral branch of the genitofemoral nerve also lies within the sheath adjacent to the femoral artery but pierces the sheath just distal to the inguinal ligament and medially, the sheath is pierced by the great saphenous vein and lymphatics. 3.5 The adductor canal (subsartorial or Hunter’s canal) is an intermuscular gutter on the medial aspect of the thigh extending from the apex of the femoral triangle to the adductor hiatus, which is an opening in the tendon of adductor magnus adjacent to the femur just above the knee. The canal is bounded: Posteriorly by adductor longus above and adductor magnus below,

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Anterolaterally by vastus medialis, Anteromedially (the roof of the canal) by a strong layer of fascia under sartorius. The adductor canal contains the: Femoral artery (with its descending genicular branch), femoral vein, nerve to vastus medialis and saphenous nerve. Question 4 4.1 A: Tensor fascia lata, B: Femoral vein, C: Lateral circumflex femoral artery. 4.2 The external iliac artery becomes the femoral artery as it passes beneath the inguinal ligament. The femoral artery runs distally, initially within the femoral sheath, to enter the adductor canal at the apex of the femoral triangle. It gives off numerous branches in the femoral triangle: A. Four branches arise just beyond the inguinal ligament: superficial epigastric artery, superficial circumflex iliac artery, superficial external pudendal artery and deep external pudendal. B. A large profunda femoris artery (deep femoral artery) is given off just beyond the termination of the femoral sheath. The profunda femoris usually gives off the lateral and medial circumflex femoral arteries (although these may arise directly from the femoral artery), numerous muscular branches, and several perforating arteries along its course. C. The femoral artery also gives off muscular branches and, just proximal to the adductor hiatus, a descending genicular branch that contributes to the arterial anastomosis around the knee. 4.3 Trochanteric and cruciate anastomosis. The most important one is the trochanteric anastomosis which lies near the trochanteric fossa of the femur, creating an extracapsular arterial ring around the femoral neck. The cruciate anastomosis lies posteriorly at the level of the lesser trochanter near the lower edge of the femoral attachment of quadratus femoris. 4.4 Great saphenous vein drains into the femoral vein at the saphenofemoral junction. The great saphenous vein receives multiple tributaries in the region of the saphenofemoral junction (superficial epigastric vein, superficial circumflex iliac vein, and external pudendal vein) but there is considerable individual variation and one or more of these superficial veins may drain directly into the femoral vein. 4.5 The femoral nerve (L2, 3, 4) is formed in the lumbar plexus within psoas major. It emerges from the lateral border of psoas major a few centimetres above the inguinal ligament lying beneath the fascia on iliacus. It enters the thigh lateral to the femoral sheath and within a few centimetres below the inguinal ligament divides into an anterior and posterior division which are often separated by the lateral circumflex femoral artery. The anterior division gives off two muscular branches (to sartorius and pectineus) and two sensory branches (the intermediate and medial cutaneous nerves of the thigh), whilst the posterior division

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supplies quadriceps femoris and articularis genus via multiple branches and gives off the saphenous nerve. 4.6 The femoral artery is best palpated midway between the anterior superior iliac spine and the pubic symphysis; this is the mid-inguinal point rather than the midpoint of the inguinal ligament. Question 5 5.1 A: small (short) saphenous vein, B: sural nerve, C: Biceps femoris muscle/ tendon, D: Semitendinosus muscle, E: Semimembranosus muscle, F: Achilles tendon/ calcaneal tendon. 5.2 The sural nerve. The sural nerve forms from branches of the tibial nerve and common fibular nerve. The sural nerve lies close and lateral to the short saphenous vein throughout its length, and is at risk during stripping of the short saphenous vein and dissection of the saphenopopliteal junction. 5.3 The small (short) saphenous vein originates from the lateral side of the foot behind the lateral malleolus and ascends the calf posteriorly in the midline. It usually perforates the popliteal fascia and passes alongside the tibial nerve to terminate in the popliteal vein in the popliteal fossa. In some cases, it terminates in a tributary of the great saphenous vein. The small (short) saphenous vein is accompanied by the sural nerve from about the mid-calf distally. 5.4 The saphenous nerve emerges from the adductor canal and perforates the fascia lata to join the great saphenous vein behind the medial aspect of the knee. It lies adjacent to the vein as it descends and passes just anterior to the medial malleolus. 5.5 The great saphenous vein originates from the medial marginal vein of the dorsal venous arch of the foot, passes just anterior to the medial malleolus, and runs up the medial side of the leg. It lies a hand’s breadth behind the medial border of the patella, travels up the medial side of the thigh and pierces the cribriform fascia covering the saphenous opening in the femoral triangle to enter the femoral vein on its anteromedial aspect. The great saphenous vein is accompanied by the saphenous nerve. 5.6 The surface marking of the saphenofemoral junction is about 2–3 cm lateral to and just below the pubic tubercle. Question 6 6.1  A: Sartorius muscle, B: Adductor longus muscle, C: Gracilis muscle, D: Semimembranosus muscle, E: Tendon of semitendinosus muscle. 6.2 The medial compartment of the thigh is separated from the anterior compartment by the medial intermuscular septum. There is no intermuscular septum between the medial compartment and the posterior compartment. The nerve of the medial compartment is the obturator nerve (Table 2.1).

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Table 2.1  Medial compartment of the thigh Muscle Gracilis

Origin

Insertion

Action

Outer surface of the ischiopubic ramus

Medial surface of proximal tibia

Adductor longus Adductor brevis

Body of pubis

Lower 2/3 of linea aspera

Inferior ramus and body of pubis Adductor portion: ischiopubic ramus Hamstring portion: ischial tuberosity

Upper 1/3 of linea aspera

Adducts hip. Flexes knee and medially rotates the flexed knee Adducts the hip Adducts the hip

Adductor magnus

Posterior surface of proximal femur, linea aspera and upper part of medial supracondylar line Adductor tubercle and lower part of medial supracondylar line

Nerve Obturator nerve (L2-4)

Adducts hip

Extends hip

Sciatic nerve: tibial part (L5, S1, 2)

6.3 The obturator nerve (L2, 3, 4) is formed within psoas major. It emerges on the medial side of psoas and exits the pelvis through the obturator foramen. In this region it divides into anterior and posterior branches: 1. the anterior branch passes in front of obturator externus above and adductor brevis below before running down behind pectineus and adductor longus. It sends a branch to the hip joint and supplies most of the adductor muscles. It then communicates with cutaneous branches of the femoral nerve in the adductor canal and supplies skin on the medial aspect of the thigh. 2. the posterior branch passes through obturator externus which it supplies and then descends behind adductor brevis on adductor magnus which it also supplies. It enters the popliteal fossa via the adductor hiatus and sends a twig to the knee joint. 6.4The medial compartment is largely supplied by branches of the profunda femoris artery. Question 7 7.1 A: Biceps femoris muscle, B: Semitendinosus muscle, C: Semimembranosus muscle, D: Gracilis muscle. 7.2 The posterior (hamstring) compartment of the thigh extends from the gluteal region to the back of the knee. It is separated from the anterior compartment by the lateral intermuscular septum but there is no septum dividing it from the medial compartment since adductor magnus has both adductor and hamstring components. The components, attachments and innervations are summerised in the posterior compartment of the thigh section (Table 2.2).

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2  Lower Limb Table 2.2  Muscles of the posterior compartment of the thigh Muscle Semimembranosus

Origin

Insertion

Action

Ischial tuberosity (superolateral facet)

Posterolateral surface of medial tibial condyle, fascia over popliteus and oblique popliteal ligament Medial surface of proximal tibia

Flexes and medially rotates the knee; extends hip

Semitendinosus

Ischial tuberosity (medial facet)

Biceps Femoris

Long head: ischial tuberosity (medial facet) Short head: lateral lip of linea aspera

Head of fibula (around lateral collateral ligament of knee)

Flexes and medially rotates the knee; extends hip Flexes and laterally rotates the knee Long head extends the hip

Nerve Sciatic nerve: tibial component (L5, S1, 2)

Sciatic nerve: common fibular component (L5, S1, 2)

7.3 The nerve of this compartment is the sciatic nerve and the muscles are supplied mainly by the profunda femoris artery via its perforating branches (supplemented by branches of the inferior gluteal artery above and the popliteal artery below). Question 8 8.1 A: Biceps femoris muscle, B: Semitendinosus muscle, C: Semimembranosus muscle, D: Medial head of gastrocnemius muscle, E: Sciatic nerve, F: Popliteal vein, G: Tibial nerve, H: Common fibular nerve, I: Head of Fibula. 8.2 The popliteal fossa is a diamond-shaped depression behind the flexed knee and its boundaries are: Medial border: superiorly, semimembranosus and the overlying semitendinosus; inferiorly, the medial head of gastrocnemius. Lateral border: superiorly, biceps femoris; inferiorly, the lateral head of gastrocnemius with the underlying plantaris muscle. Floor (from above downwards): the posterior surface of the distal femur, the capsule of the knee joint reinforced by the oblique popliteal ligament, and the posterior aspect of the proximal tibia covered by popliteus and its fascia. Roof: the popliteal fascia which emerges with the fascia lata proximally and the fascia cruris distally. 8.3 The contents (from superficial to deep) are: tibial and common fibular nerves, popliteal vein, popliteal artery and popliteal lymph nodes. 8.4 The middle genicular artery pierces the oblique popliteal ligament and posterior joint capsule to supply the cruciate ligaments.

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8.5 The functions of the popliteus muscle are: (1) When the knee is fully extended and the foot is planted, popliteus rotates the femur laterally on the tibia, (2) When the knee is flexed and non-weightbearing, popliteus medially rotates the leg and, (3) Unlocks the knee at the beginning of flexion. Question 9 9.1 Anterior cruciate ligament injury. 9.2 A: Superior articular surface of tibia (medial facet), B: Tibial tuberosity, C: Attachment of horns of medial meniscus, D: Attachment of posterior cruciate ligament, E: Attachment of anterior cruciate ligament. 9.3 The two cruciate ligaments lie inside the capsule of the knee joint but outside the synovial membrane. The anterior cruciate ligament (ACL) is attached to the anterior part of the intercondylar area of the tibia and ascends posteriorly in the intercondylar fossa to attach to the lateral femoral condyle. The posterior cruciate ligament (PCL) is attached to the posterior part of the intercondylar area of the tibia and a small adjacent area on the posterior surface of the tibia and ascends anteriorly in the intercondylar fossa to the medial femoral condyle. 9.4 The lateral meniscus is C-shaped and its posterior horn attaches to the tendon of popliteus which is attached to its periphery and separates it from the lateral collateral ligament and to the medial femoral condyle. These attachments cause the lateral meniscus to be more mobile than the medial meniscus. The medial meniscus is comma-shaped and its horns attach to the tibial plateau. Posteriorly, its periphery is attached to the knee joint capsule and medial collateral ligament, therefore it is much less mobile than the lateral meniscus. As a result of this, it is much more prone to injury. 9.5 Blood supply of the knee is by a rich arterial anastomosis around the knee. The network receives contributions from (1) the genicular branches of the popliteal artery, (2) the descending genicular branch of the femoral artery, and (3) a recurrent branch from the anterior tibial artery. The middle genicular artery supplies the cruciate ligaments. Lymphatic drainage is to popliteal lymph nodes. Innervation of the joint capsule and ligaments are supplied by articular branches of nerves supplying the muscles acting on the joint (Hilton’s law); the femoral, sciatic (tibial and common fibular nerves) and obturator nerves. Question 10 10.1 Compartment syndrome 10.2 A: Superior extensor retinaculum, B: Superficial fibular nerve, C: Tibial tuberosity, D: Medial malleolus. 10.3 The anterior (extensor) compartment is bounded by the tibia, interosseous membrane, fibula, anterior intermuscular septum and deep fascia. The lateral (fibular/evertor) compartment lies between the anterior and posterior intermuscular septa and the deep fascia and fibula. The components, attachments and innervations are summarised in the section of the anterior and lateral compartments of the leg, respectively (Tables 2.3 and 2.4).

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2  Lower Limb Table 2.3  Muscles of the anterior compartment of the leg Origin

Insertion

Function

Upper half of the lateral shaft of tibia and interosseous membrane and overlying deep fascia Middle half of anterior shaft of fibula and interosseous membrane

Medial cuneiform and adjacent base of first metatarsal

Dorsiflexion of ankle and inversion of the foot

Dorsal aspect of base of distal phalanx of great toe

Deep fibular nerve (L5)

Extensor digitorum longus

Lateral condyle of tibia, proximal anterior surface of fibula, interosseous membrane and overlying deep fascia

Peroneus tertius

Lower third of anterior surface of fibula and interosseous membrane

Extensor hoods over proximal phalanges with slips to base of middle and distal phalanges of lateral four digits Dorsum of base of fifth metatarsal

Extension of great toe and dorsiflexion of ankle Extension of lateral four toes and dorsiflexion of ankle Dorsiflexion of ankle and eversion of foot

Deep fibular nerve (L5, S1)

Muscle Tibialis Anterior

Extensor Hallucis longus

Innervation Deep fibular nerve (L4, 5)

Deep fibular nerve (L5, S1)

Table 2.4  Muscles of the lateral compartment of the leg Muscle Fibularis Longus

Fibularis Brevis

Origin

Insertion

Function

Head and upper two-thirds of lateral side of fibula Lower two-thirds of lateral side of fibula

Base of first metatarsal and adjacent medial cuneiform Tuberosity on lateral side of base of fifth metatarsal

Eversion of foot and weak plantarflexion of ankle Fibularis longus helps to maintain the lateral longitudinal and transverse arches of the foot

Innervation Superficial fibular nerve (L5, S1)

10.4 The deep fibular nerve innervates the muscles of the anterior compartment. The superficial fibular nerve innervates the muscles of the lateral compartment. The anterior tibial artery supplies the muscles in the anterior and lateral compartments and the fibular artery contributes to both compartments. 10.5 There are two extensor retinacula: superior and inferior. The superior extensor retinaculum is attached to the anterior borders of the tibia and fibula above the ankle. The inferior extensor retinaculum is Y-shaped. It is attached laterally to the upper surface of the calcaneus and diverges medially as two limbs, one of which is attached to the medial malleolus and the other to the medial side of the plantar aponeurosis. Question 11 11.1 A: Lateral malleolus, B: Fibularis longus, C: Calcaneus. 11.2 The tibial nerve innervates the muscles of the posterior compartment. The popliteal and posterior tibial arteries supply the muscles in the posterior compartment, and the fibular artery also contributes to the compartment.

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11.3 The posterior (flexor) compartment is bounded by the posterior intermuscular septum, fibula, interosseous membrane, tibia, and deep fascia; it has superficial and deep parts separated by the deep aponeurosis of soleus and a transverse layer of fascia (Tables 2.5 and 2.6). Superficial muscles of the calf  Table 2.5  Muscles of the posterior compartment of the leg (superficial muscles) Muscle Gastrocnemius

Soleus

Origin

Insertion

Function

Lateral head: lateral surface of lateral femoral condyle Medial head: posterior surface of medial femoral condyle Head and upper quarter of fibula, soleal line and middle third of medial border of tibia, and fibrous arch between tibia and fibula

Posterior surface of calcaneus via Achilles tendon

Plantarflexion of ankle Flexion of knee

Innervation Tibial nerve (S1, S2)

Plantarflexion of ankle

Deep muscles of the calf  Table 2.6  Muscles of the posterior compartment of the leg (deep muscles) Muscle Flexor digitorum longus Flexor hallucis longus

Tibialis posterior

Origin

Insertion

Function

Medial part of posterior surface of tibia below soleal line Distal posterior surface of fibula and adjacent interosseous membrane

Base of distal phalanges of lateral four digits Base of distal phalanx of great toe

Flexion of lateral four toes Plantarflexion of ankle

Posterior surface of tibia below soleal line, interosseous membrane and adjacent fibula

Tuberosity of navicular, medial cuneiform, and bases of metatarsals 2-4

Flexion of great toe (important in ‘toe-off’ in the gait cycle) Plantarflexion of ankle Supports medial longitudinal arch of foot Inversion and adduction of foot Plantarflexion of ankle Supports medial longitudinal arch of foot

Innervation Tibial nerve (S1, 2)

Tibial nerve (S1, 2)

Tibial nerve (L4, L5)

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11.4 The leg is innervated by the sensory branches of the common fibular and tibial nerve (sural nerve) except the medial side which is innervated by the sensory branch of the femoral nerve (saphenous nerve). Question 12 12.1 A: Flexor retinaculum, B: Tibialis posterior tendon, C: Flexor digitorum longus tendon. 12.2 Tibialis posterior muscle. 12.3 The tarsal tunnel is a gutter covered by flexor retinaculum between the tibia and calcaneus and transmits the following structures (from front to back); the tibialis posterior tendon, flexor digitorum longus tendon, posterior tibial artery and vein, tibial nerve, and flexor hallucis longus tendon. 12.4 The flexor retinaculum extends posteroinferiorly from the medial malleolus to the medial side of the calcaneus. Inferiorly, it blends with the plantar aponeurosis. Question 13 13.1 A: Medial malleolus, B: Lateral malleolus, C: Talus. 13.2 Deltoid ligament injury. 13.3 The ankle joint is strengthened by strong collateral ligaments. Medial (deltoid) ligament is a large, strong triangular ligament with deep (anterior tibiotalar) and superficial parts. The latter fans out from the medial malleolus to the medial tubercle of the talus posteriorly, the navicular tuberosity anteriorly, and the edge of the sustentaculum tali and spring ligament between. Lateral ligament has three parts and includes the anterior and posterior talofibular and calcaneofibular ligaments. 13.4 Blood supply is from anterior and posterior tibial and fibular (peroneal) arteries and nerve supply is from the deep fibular and tibial nerves. 13.5 (1) Anteriorly from medial to lateral: tibialis anterior tendon, anterior tibial vessels, deep fibular nerve, extensor hallucis longus tendon, extensor digitorum longus tendon and fibularis tertius. (2) Branches of the superficial fibular nerve cross the joint anterolaterally. (3) The great saphenous vein and saphenous nerve cross the ankle just anterior to the medial malleolus. Question 14 14.1 A: Calcaneus, B: Talus, C: Navicular, D: Medial cuneiform, E: 1st metatarsal bone, F: Sustentaculum tali. 14.2 Subtalar joint (talocalcaneal joint) is between a large concave posterior facet on the undersurface of the talus and a corresponding convex facet on the superior surface of the calcaneus. The joint is stabilised by several talocalcaneal ligaments including an interosseous talocalcaneal ligament lying in the tarsal sinus (a tunnel inferior to the neck of the talus).

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14.3 Talocalcaneonavicular joint is between the rounded head of the talus and, from front to back, the navicular, plantar calcaneonavicular (spring) ligament, and the superior surface of the sustentaculum tali of the calcaneus. Numerous ligaments reinforce the joint including the bifurcate ligament running from the upper medial surface of the calcaneus to the dorsal surfaces of the cuboid and navicular bones and the strong plantar calcaneonavicular ligament between the sustentaculum tali behind and the navicular in front. 14.4 Calcaneocuboid joint is between the anterior surface of the calcaneus and the posterior surface of the cuboid. It is strengthened by the bifurcate ligament and the long and short plantar ligaments. 14.5 The bones of the foot do not lie flat on the ground but are organized into two medial and lateral longitudinal arches and a transverse arch. 14.6 The medial and lateral longitudinal arches extend from the posteroinferior part of the calcaneus to the heads of the metatarsals. The medial longitudinal arch is higher than the lateral and supported by the plantar calcaneonavicular ­ligament, tibialis anterior and posterior. The lateral longitudinal arch is supported by the long and short plantar ligaments and the tendon of fibularis longus. Both arches are strengthened by the plantar aponeurosis and the long and short flexors of the toes. 14.7 The transverse arch lies in the coronal plane and is formed by the cuneiforms, cuboid and the bases of the metatarsals which are linked together by ligaments. The arch is strengthened by the tendon of fibularis longus which passes obliquely across the sole. Question 15 15.1 A: Flexor digitorum brevis, B: Abductor hallucis. 15.2 The foot comprises of four layers and a neurovascular plane: 1st layer lies immediately deep to the plantar aponeurosis and comprises three short muscles (flexor digitorum brevis and abductors of the big and little toes). The neurovascular plane (the medial and lateral plantar vessels and nerves) lies between the 1st and 2nd layer. 2nd layer consists of the quadratus plantae muscle, the tendon of flexor hallucis longus and four lumbrical muscles. 3rd layer comprises three short muscles (two of which are connected to the great toe). 4th layer comprises the four dorsal and three plantar interossei together with the tendons of fibularis longus and tibialis posterior. 15.3 The medial and lateral plantar nerves (S1, 2, 3) originate from the tibial nerve under the flexor retinaculum, lie between the first and second layer of the foot and innervate structures in the foot. The medial plantar nerve is the major sensory nerve of the sole of the foot including the plantar aspect of the medial three and a half toes via its digital branches. It also supplies four intrinsic muscles: abductor hallucis, flexor digitorum brevis, flexor hallucis brevis and the first lumbrical. All of the other intrinsic muscles of the foot are innervated

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by the lateral plantar nerve, which also provides sensation to the lateral aspect of the anterior sole and plantar surface of the lateral one and a half toes. 15.4 Three short muscles (flexor digitorum brevis and abductors of the big and little toes) which lie immediately deep to the plantar aponeurosis. Question 16 16.1  A: Deep fibular nerve, B: Extensor hallucis longus, C: Inferior extensor retinaculum. 16.2 The superficial fibular nerve innervates most of the skin of the dorsum of the foot except for the web space between the first and second toes. It runs over the extensor retinacula. 16.3 The web space between the first and second toes is supplied by the deep fibular nerve, which runs under the extensor retinacula. 16.4 The long tendons of extensor digitorum longus and extensor hallucis longus; extensor digitorum brevis; and neurovascular structures (the dorsalis pedis artery and deep and superficial fibular nerves). 16.5 The dorsalis pedis artery is the continuation of the anterior tibial artery after it crosses the ankle joint midway between the malleoli. It runs forward across the dorsum of the foot between the tendons of extensor hallucis longus and extensor digitorum longus.

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Thorax S. Ali Mirjalili and Kiarash Taghavi

Part One: Questions Question 1 You are inserting an emergency chest drain for a traumatic haemopneuomothorax. 1.1 Name muscles A, B and C.

B

C

A

S.A. Mirjalili (*) Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand e-mail: [email protected] K. Taghavi Department of Paediatric Surgery, Starship Hospital, Auckland, New Zealand e-mail: [email protected] © Springer Nature Singapore Pte Ltd. and People’s Medical Publishing House 2017 S.A. Mirjalili (ed.), Anatomy for the Generic Surgical Sciences Examination (GSSE), DOI 10.1007/978-981-10-3883-9_3

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1.2 What landmarks will you use for placing the chest drain? What structures are avoided by placing the chest drain here? 1.3 Will you place the chest drain directly above or below the rib and why? 1.4 What is the arrangement of structures within the intercostal neurovascular bundle and between which muscular layers does this lie? 1.5 The patient requires an emergency lateral thoracotomy, which muscles may be divided/retracted?

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Question 2 A patient with anastomotic leak needs a peripherally inserted central catheter (PICC) for parenteral nutrition (PN). 2.1 Name structures A and B in the venogram. A

B

2.2 The catheter is inserted via the right cephalic vein. Name each sequential venous structure the tip will pass through before entering the right atrium. 2.3 What is the anatomical structure that marks the beginning of B. 2.4 Name labeled structures A and B in the prosection below. A

B

2.5 What is the anatomical landmark that marks the beginning of A. 2.6 What is the surface landmark for the formation of B? 2.7 Name at least three venous structures that drain directly into B? 2.8 What is the surface landmark for the formation of the superior vena cava and where it enters the right atrium?

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Question 3 A pancoast tumour from apical lung cancer has caused thoracic outlet syndrome affecting structures travelling between the anterior and middle scalene muscles.

B A C 3.1 Above is a typical rib, what defines ‘typical’? Name structures A, B and C in the image above. Which ribs are atypical? 3.2 Describe the borders of the superior thoracic inlet. 3.3 Describe characteristic bony landmarks of the first rib and the relevant attachments and structures passing over it. 3.4 Name structures A, B and C in the image above.

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B C

3.5 Name all the structures entering the superior thoracic aperture and their relations.

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Question 4 Following cardiac surgery your patient suffers from persistent chylothorax (lymph fluid collection within the pleural cavity) as evidenced by high levels of triglycerides and lymphocytes.

4.1 What forms the thoracic duct and how does it enter the thoracic cavity. 4.2 The image above is a percutaneous thoracic ductography which was done to rule out chyle leak. Describe the course and relations of the thoracic duct through the posterior and superior mediastinum. 4.3 Where does the thoracic duct ultimately drain and what are its relations at the superior thoracic inlet? 4.4 Which areas are NOT drained by the thoracic duct? How are these areas drained and where do these lymphatic vessels ultimately empty?

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Question 5 You are performing a gastroscopy for investigation of melaena. Clinical images are shown below. a

b

c

d

e

f

g

h

i

5.1 Where does the oesophagus commence and terminate? What is the average length of the oesophagus? 5.2 Name the narrowest portion of the oesophagus and describe other potential areas of anatomical constriction. 5.3 In the superior mediastinum the oesophagus is perforated. Name its anatomical relations and therefore structures at risk of damage. 5.4 In the posterior mediastinum there is sudden and large amounts of bleeding – name the vascular relations of the oesophagus here. 5.5 Name the arterial supply of the thoracic oesophagus. 5.6 At what level does the oesophagus pass through the diaphragm? What structures travel with it?

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Question 6 Following the surgical ward round you notice that a patient has a newly raised hemidiaphragm on chest x-ray and you suspect iatrogenic phrenic nerve palsy.

6.1 Describe the motor and sensory distributions of the phrenic nerves. 6.2 The patient had undergone a brachial plexus nerve block in the neck. Describe the course and relations of the phrenic nerve in the neck. 6.3 Below is a view of the mediastinum from the right hemithorax. Name structures A, B, C, D and E.

A D B E C

6.4 The patient had undergone mediastinoscopy. Describe the relations of the left phrenic nerve to the hilum of the lung and superior intercostal vein (lateral).

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6.5 As the left phrenic nerve travels along the fibrous pericardium what structures run with it. 6.6 The patient had undergone diaphragmatic repair after traumatic rupture – where do the left and right phrenic nerves penetrate the diaphragm? Describe their distribution.

Question 7 A female fencing Olympiad was training and she got hit in the 7th intercostal space in the right mid-axillary line in a vertical manner.

Expiration Inspiration

7.1 What are the levels of pleural reflection in the – lower sternal edge at the left and right? Mid-clavicular line? Mid-axillary line? 7.2 Name each layer and structure you would expect the sabre to pierce from superficial to deep before reaching the lung parenchyma 7.3 Would you clinically anticipate a liver or renal injury?

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Question 8 Joseph is a long term smoker and is undergoing a bronchoscopy. He is undergoing investigation for haemoptysis. A prosection of the larynx and trachea is attached. 8.1 What is the name of the internal ridge located at A?

A

8.2 At what level do the main bronchi form and what are the anterior and posterior landmarks? 8.3 What other significant structures also lie in this plane? 8.4 What is the surgical significance of a bronchopulmonary segment? What structures lie between bronchopulmonary segments? 8.5 You enter the left main bronchus – describe the arrangement of the bronchopulmonary segments of the left lung. 8.6 What are the anatomical reasons that foreign bodies tend to enter the right main bronchus?

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Question 9 A young woman presents to a surgical clinic with a breast lump. Mammography showed dense breast tissue only. However tissue core biopsy of the lump confirmed a lobular carcinoma of the breast.

9.1 Name muscles A and B.

A

B

9.2 What are the landmarks that define the limits of the breast. 9.3 Describe the anatomical structure of the breast.

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9.4 Name the main arterial supplies of the breast. 9.5 Describe the lymphatic drainage of the breast. 9.6 What is the posterior limit of the breast, what constitutes this fascia? 9.7 What structures penetrate the clavipectoral fascia and describe their branches.

Question 10 After blunt trauma to the chest your patient is suffering significant blood loss from their chest drain. 10.1 Name the structure labeled A.

A

10.2 Where does this structure originate and what are its’ surface landmarks? 10.3 Describe the branching pattern of this structure. 10.4 Describe the divisions and branches of the subclavian artery. 10.5 Name the arterial supply of the posterior thoracic wall and its origin. 10.6 The blood in the drain appears venous - where does the azygos vein form, what does it drain, and where does it terminate?

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Question 11 A patient is referred to the surgical outpatient clinic with bilateral palmer hyperhidrosis. 11.1 What are the structures labeled A and B?

B

A

11.2 Describe the thoracic sympathetic trunk; its’ major ganglia, communications and what it supplies. 11.3 What are the named splanchnic nerves, how do they enter the abdomen and where do they synapse? 11.4 What is the landmark for the cervicothoracic ganglia (stellate) and what are its’ important relations? 11.5 What is the key step in a cervical sympathectomy?

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Question 12 Your patient suffers a perioperative myocardial infarction following a right hemicolectomy. 12.1 Name structures A, B, C, D, E and F.

B A

C

D

E F

12.2 Name the main branches of the left coronary artery and the myocardial regions they supply. 12.3 Name the branches of the right coronary artery and myocardial regions they supply. 12.4 What is meant by a right or left dominant heart? And what proportions of individuals fall into each group. 12.5 Your patient develops atrial flutter. What is the blood supply of the sinoatrial node? If there are variations to this, in what proportion of patients do these occur?

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Question 13 A post-surgical patient on the ward undergoes sudden decompensation overnight that results in death. Post-mortem findings are of a large saddle embolus at the bifurcation of the pulmonary artery. 13.1 Name structures A, B, C, D, E and F.

B E A

C

D

F

13.2 What is the relationship of the right pulmonary artery and right main bronchus at the root of the lung? 13.3 The ductus arteriosus serves as a right-to-left shunt in fetal circulation to circumvent the pulmonary circulation. Name another right-to-left shunt in fetal circulation. 13.4 What structure hooks around the ligamentum arteriosus (the fibrous remnant of the ductus arteriosus) and what does this supply?

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Question 14 You wish to access the pericardium during cardiac surgery.

14.1 Name the layers and coverings of the heart you would pass through if you inadvertently penetrated the myocardium. 14.2 What provides sensory supply to these layers? 14.3 With regards to the two sinuses within the pericardial cavity: 14.3.1 If you put your finger between the two left and two right pulmonary veins which sinus would you be in? 14.3.2 If your finger lies between the aorta and pulmonary artery in front and the superior vena cava behind which sinus would you be in?

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Question 15 You are scrubbed in theatre and your consultant gives you the scalpel to perform a thoracotomy at the right 5th intercostal space spanning the lateral aspect of the chest wall. 15.1 Name structures A, B, C and D.

A

C

B

D

15.2 Name the muscles of the external chest wall you would cut or retract and their attachments. 15.3  Name the intercostal muscles you would incise and describe their attachments. 15.4 Intercostal muscles fibres are seen to run from lateral to medial (top to bottom). What intercostal muscle is this? 15.5  Which other muscles lie in the same plane as the innermost intercostal muscles?

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Question 16 You are studying the 3D volume rendered image of an infant skeleton in the Radiology Department. 16.1 Name structure A, B, C and D.

A B

C

D

16.2 What are the costochondral joints, interchondral joints and sternocostal joints? 16.3 Where does the second rib attach anteriorly and posteriorly? 16.4 What type of joint is the sternoclavicular joint? 16.5 What type of joint is the xiphisternal joint? 16.6 What type of joints are the costochondral joints?

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Part Two: Answers Question 1 1.1 A- Serratus anterior, B- External intercostal muscle, C- Internal intercostal muscle. 1.2 Anterior to mid-axillary line, 4th IC space. Avoiding: long-thoracic nerve, liver and spleen. 1.3 Directly above as this avoids the dominant neurovascular bundle that lies directly below each rib in the costal groove. 1.4 Intercostal vein, artery and nerve (superior to inferior), between the internal intercostal and innermost intercostal muscles. 1.5 Latissumus dorsi, serratus anterior, external oblique, external intercostal, internal intercostal and innermost intercostal. Question 2 2.1 A- Right cephalic vein, B- Right subclavian vein. 2.2 Right cephalic vein, right subclavian vein, right brachiocephalic vein and superior vena cava. 2.3 The lateral edge of the 1st rib. 2.4 A-Right axillary vein, B- Left brachiocephalic vein. 2.5 Inferior border of teres major. 2.6 Sternoclavicular joint. 2.7 Vertebral veins, internal thoracic veins, inferior thyroid veins, left superior intercostal vein and thymic vein. 2.8 It forms at the lower border of the 1st right costal cartilage and enters the right atrium at the lower border of the 3rd right costal cartilage. Question 3 3.1 Head is beveled by two articular facets. A- Head, B- Neck, C- Tubercle. Atypical ribs are the first, eleventh and twelfth, each of which make a single synovial joint with only its own vertebra. 3.2 T1 posteriorly, pair of 1st rib laterally, costal cartilage of 1st rib and manubrium anteriorly. 3.3 The scalene tubercle provides attachment of the scalenus anterior. Behind this is the “subclavian groove” occupied by the lower nerves of the brachial plexus in close proximity to the subclavian artery. In front of the scalene tubercle lies a poorly defined groove for the subclavian vein. The thoracic sympathetic trunk passes over the neck of the rib. 3.4 A- Right clavicle, B- Left first rib, C- Left 3rd costal cartilage. 3.5 Midline: The oesophagus lies against T1 (thoracic duct to the left) and the trachea anterior to this (right recurrent laryngeal nerve runs in the tracheo-­esophagela groove). Laterally (from anterior to posterior): The subclavian vein, scalenus anterior with the phrenic nerve on its fascia, subclavian artery and vagus nerve. Posteriorly: The sympathetic chain.

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Question 4 4.1 It is formed by the cisterna chyli (T12) between the aorta and azygos vein and it enters the thoracic cavity from behind the right crus. 4.2 It passes upwards to the right of the aorta, and then comes to lie against the right side of the oesophagus. At the sternal angle it passes behind the oesophagus to the left side in the superior mediastinum. 4.3 At the superior thoracic inlet it lies anterior to the intercostal branches of the aorta before arching forwards across the dome of the left pleura, to enter the point of confluence of the left internal jugular and subclavian veins (via 2–3 branches). 4.4 Lymph from the posterior right thoracic wall enters the right lymphatic duct. The right upper limb drains via the right subclavian trunk and the right head and neck via the right jugular lymph trunk. These three trunks enter at the confluence of the right internal jugular and subclavian veins. Question 5 5.1 It extends from the cricoid cartilage (level of C6 vertebra) to the cardiac orifice of the stomach (T10 at the left seventh costal cartilage) with a total length of 25 cm. 5.2 The narrowest part of the Oesophagus is at its commencement (cricopharyngeal sphincter of the cricopharyngeus muscle). Other slight constrictions occur where it is crossed by the aortic arch (22 cm from incisors), by the left main bronchus (27 cm from incisors) and where it passes through the oesophageal hiatus of the diaphragm (38 cm from incisors). The left atrium lies anteriorly and can indent if enlarged. 5.3 In the superior mediastinum the oesophagus is crossed by the aortic arch on the left and azygos vein on the right. The thoracic duct lies to the left. The trachea is immediately anterior. The recurrent laryngeal nerves lie in the tracheo-­esophageal groove. 5.4 In the posterior mediastinum, the oesophagus is crossed anteriorly by the left main bronchus and the right pulmonary artery. Also an important anterior relation is the left atrium. 5.5 The upper oesophagus is supplied by the inferior thyroid arteries. The middle portion by oesophageal branches from the aorta and the lower portion by oesophageal branches of the left gastric artery. 5.6 T10 at the seventh costal cartilage on the left. Anterior and posterior vagal trunks (from predominantly left and right vagi respectively). Oesophageal branches from the left gastric artery. Oesophageal tributaries of the left gastric vein. Lymphatics to the preaortic nodes of the coeliac group. Question 6 6.1 Each phrenic nerve is the sole motor supply to its half of the diaphragm (including the crus). Sensory to: the diaphragm (except the most peripheral parts which receive intercostal afferent fibres), mediastinal pleura, fibrous pericardium, parietal layer of serous pericardium, and central portions of the diaphragmatic pleura and peritoneum.

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6.2 Arising principally from C4 (C3-C5) in the neck, it passes down over the anterior scalene muscle, across the dome of the pleura and behind the subclavian vein. 6.3 A- Right common carotid artery, B- Left brachiocephalic vein, C- Superior vena cava, D- Right brachiocephalic, E- Right phrenic nerve. 6.4 The left phrenic nerve is anterior to the hilum of the lung and lateral to the superior intercostal vein (whereas the vagus nerve is posterior to the hilum of the lung and superior intercostal vein). 6.5 The pericardiophrenic artery (a branch of the internal thoracic) with companion veins. 6.6 Right phrenic nerve passes through the diaphragm via the vena caval foramen (T8) in the central tendon. The left phrenic nerve pierces the muscular part of the diaphragm at the apex of the left ventricle. On the under surface of the diaphragm, each phrenic nerve splits into three main branches (anterior, lateral, posterior) which radiate from the point of entry. Question 7 7.1 Tracing the pleura inferiorly from the sternoclavicular joint, it meets its fellow at the 2nd rib level (sternal angle). It passes vertically down behind the sternum down to the 4th costal cartilage, the left then moves more laterally following this. Each crosses the mid-clavicular line at the 8th rib, and mid-axillary line at the 10th rib. 7.2 Skin, Subcutaneous tissue (misses the breast that ends at the 6th rib), serratus anterior and/or external oblique muscle (long thoracic nerve at risk posterior to mid-axillary line), external intercostal muscle, internal intercostal muscle, (neurovascular plane), innermost intercostal muscle, endothoracic fascia, parietal pleura, pleural fluid and visceral pleura. 7.3 On the right the liver apex reaches the 5th rib and the right border ranges from ribs 7 to 11 in the mid-axillary line and so is at risk of injury. The upper pole of the left kidney may overly the 11th rib, but the right kidney seldom gets so high. Question 8 8.1 The carina. 8.2 Sternal angle/angle of Louis. Anteriorly 2nd costal cartilage and manubriosternal joint, and posteriorly the lower T4 vertebrae. 8.3 Besides passing through the bifurcation of the trachea, it passes through the concavity of the arch of the aorta, and just above the bifurcation of the pulmonary trunk, the azygos vein enters the subclavian vein at this level, the thoracic duct passes behind the oesophagus from the right to the left side, the ligamentum arteriosum and the superficial and deep parts of the cardiac plexus are also present. 8.4 It represents the portion of the lung supplied by a segmental bronchus. The pulmonary and bronchial arteries run through the center of the segment while the pulmonary veins are formed from tributaries which do not closely follow the bronchi but tend to run in the intersegmental septa.

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8.5 Bronchopulmonary segments: LEFT Upper (3)

Middle (2) Lower (5)

Apicoposterior Apicoposterior Anterior Superior Lingual Inferior Lingual Apical (superior) Medial (cardiac) Anterior basal Lateral basal Posterior basal

8.6 The carina lies to the left of midline. Also the right main bronchus is slightly more vertical, wider and short than the left main bronchus. Question 9 9.1 A- Pectoralis major. B-Pectoralis minor. 9.2 The breast lies in the subcutaneous tissue from the midline to the mid-axillary line, overlying ribs 2–6. The axillary tail may extend into the medial wall of axilla however. 9.3 It is composed of modified apocrine glands. 15–20 lactiferous ducts converge in a radial direction to open into the nipple. Suspensory ligaments of Cooper connect the dermis of skin to the posterior capsule. 9.4 Blood supply: (a) Lateral thoracic artery (branch from 2nd part of axillary artery) important contributor. (b) Intercostal branches from internal thoracic artery (2nd and 3rd spaces are the largest). (c) Pectoral branches from the thoracoacromial artery (a branch of 2nd part of the axillary artery) supply the upper breast. 9.5 Lateral breast drains to axillary and infraclavicular lymph nodes and medial breast drains into the internal (parasternal) nodes. Important: Lymph flows between these areas and also across the midline. Lymph nodes of the axilla, 35 to >50 in number, grouped into: (a) Anterior or pectoral group, along the medial wall of the axilla with the lateral thoracic artery, receive major part of the breast lymphatic drainage. (b) Posterior or subscapular group, along the posteromedial wall of the axilla, it receives lymph from the axillary tail of the breast (c) These then drain to the central and apical groups. 9.6 The posterior limit is the superficial fascia, an upward continuation of Scarpa’s fascia, and is condensed to form the posterior capsule of the breast. Between this capsule and the fascia over pectoralis major is the relatively avascular retro-­ mammary space (see image below).

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Deep layer

Breast lies within the superficial fascia

Superficial layer

Non-lactating breast

Submammary space Pectoralis major Lactating breast

Secretory lobule containing alveoli Rib

9.7 Two passing inwards and two passing outwards; namely the thoraco-acromial trunk (branches are clavicular, humeral, acromial and pectoral) and the lateral pectoral nerve passing outwards, and the cephalic vein and lympathics passing inwards. Question 10 10.1 Right internal thoracic artery (formerly the internal mammary). 10.2 It originates from the first part of the subclavian artery and passes vertically downwards a finger’s breadth from the border of the sternum. 10.3 It gives off two anterior intercostal arteries in each intercostal space. It also gives off a pericardiophrenic branch which runs with phrenic nerve to supply the nerve, pleura, fibrous pericardium and parietal pericardium. At the costal margin it divides into the superior epigastric and musculophrenic arteries. 10.4 The subclavian is divided into three parts with five branches: (a) The first part (before passing behind scalenus anterior) has three branches: the vertebral artery, thyrocervical trunk (gives off the inferior thyroid, transverse cervical and suprascapular arteries), and the internal thoracic artery. (b) Second part (behind scalenus anterior) has the costocervical trunk (gives off the superior intercostal and deep cervical arteries).

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(c) Third part (lateral to scalenus anterior) lies behind the prevertebral fascia on the floor of posterior triangle and gives off the dorsal scapular artery (sometimes this arises from the second part). 10.5 The upper two spaces are supplied by the superior intercostal artery (from the costocervical trunk). The descending thoracic aorta gives nine posterior intercostal arteries and a subcostal artery. Each posterior intercostal artery gives off a small collateral branch. 10.6 Azygos vein: (a) Forms by confluence of ascending lumbar and subcostal vein on the right and then passes through the aortic opening under the right crus. (b) Drains: (i) The lower eight spaces (the first space is drained by the supreme intercostal vein which goes to either vertebral or brachiocephalic vein) (ii) The second and third spaces are drained by the superior intercostal veins. On the right it drains into the azygos and on the left it runs forward over the arch of the aorta (important: relation to the phrenic and vagus nerves) to empty to the left brachiocephalic. (iii) The two hemiazygos veins join it at T8 and T9. (iv) Also drains right bronchial veins and veins of the middle oesophagus. (c) Terminates at the sternal angle (T4) arching forward to drain into the superior vena cava. Question 11 11.1 A Right thoracic sympathetic trunk (lying on neck of ribs, continues inferiorly by passing behind the medial arcuate ligament), B. Left cervicothoracic (stellate) ganglion. 11.2 It consist of 12 discrete ganglia, each receives a white ramus from the corresponding anterior ramus of the spinal nerve. After a post-ganglionic relay the grey ramus is given to each thoracic nerve. It delivers autonomic sympathetic supply to the heart (cervical and upper thoracic ganglia via cardiac plexus), lungs, trachea and oesophagus. 11.3 Three splanchnic nerves arise from lower eight ganglia; greater, lesser and least. Each pierces the ipsilateral crus to relay in the coeliac ganglia. 11.4 Classically the first thoracic and inferior cervical ganglia are fused as a single mass overlying the neck of the first rib, posteromedial to the vertebral artery. The first thoracic nerve passes more laterally. Between these two lies the supreme intercostal vein medially and superior intercostal artery laterally. 11.5 The cervical sympathectomy involves excision of the second and third thoracic ganglia and the intervening trunk. Question 12 12.1 A- Brachiocephalic trunk, B- Left common carotid artery, C- Left subclavian artery, D- Ligamentum arteriosum, E- Pulmonary trunk, F- Anterior interventricular artery. 12.2 The left coronary arises from the left aortic sinus (behind the pulmonary trunk) and divides into two main branches:

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(a) Circumflex branch (i) Within the first few mm it gives off the SA nodal artery (in 40%) (ii) In essence it is a continuation of the left coronary artery posteriorly in the atrioventricular groove (iii) It gives off ventricular branches (iv) It anastomoses with right coronary. (b) Anterior interventricular artery (i) It runs down the interventricular groove to anastomose with the posterior interventricular branch of the right coronary. (ii) It gives off several large ventricular branches (diagonal or obtuse marginal vessels). 12.3 The right coronary arises from the right aortic sinus: (a) It gives off branches to both the atrium and ventricle (b) The largest atrial branch is given off early, the SA nodal artery, in 60% of individuals. (c) At the inferior border the right marginal artery passes along the right ventricle, this gives off the AV nodal artery. (d) On the diaphragmatic surface the posterior interventricular branch is given off. 12.4 Dominance refers to which coronary gives the posterior interventricular artery. In 90% of hearts the posterior interventricular comes from the right coronary, thus ‘right dominant’. In 10% of hearts the posterior interventricular artery is given off a large anterior interventricular from the left coronary, thus ‘left dominant’. 12.5 It is supplied via the SA nodal artery which arises from the right coronary artery in 60% and left coronary artery in 40%. Question 13 13.1 A- Right pulmonary veins, B- Right main bronchus, C- Right lower lobe of lung, D- Left atrium, E- Left main bronchus, F- Descending aorta. 13.2 The right pulmonary artery passes below the carina, anterior to the oesophagus, and at the lung root is kept anterior to the right main bronchus by the upper lobe bronchus. 13.3 Foramen ovale. 13.4 The left recurrent laryngeal nerve (branch of vagus) hooks around the ligamentum arteriosum and passes superiorly on the right side of the aortic arch, and continues up the tracheoesophageal groove. Both recurrent laryngeal nerves supply the whole trachea, the adjacent oesophagus and supplies the cardiac branches. They are of utmost importance because of their supply to the muscles of the larynx (supplies all laryngeal muscles except the cricothyroid and sensation to laryngeal mucosa below the vocal fold). They are also important due to their relationship with the thyroid gland.

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Question 14 14.1 Fibrous pericardium, parietal serous pericardium, visceral serous pericardium, myocardium. 14.2 Fibrous pericardium (phrenic nerve) and parietal layer of the serous pericardium (phrenic nerve). The visceral layer of serous pericardium has no sensation. 14.3: 14.3.1 The oblique sinus is a cul-de-sac resulting from the wide separation of the four pulmonary veins and the inferior vena cava. 14.3.2 The transverse sinus. It is useful in occluding the pulmonary trunk and aorta during pulmonary embolectomy and other cardiac operations. Question 15 15.1 A- Pectoralis major, B- Pectoralis Minor, C- Latissmus dorsi, D- Rectus abdominis 15.2 Latissimus dorsi (arising from: T7-lumbosacral spinous processes, central ridge of the posterior iliac crest; inserts into the floor of the intertubercular groove) and serratus anterior (arising from a series of digitations with the upper eight ribs; inserts into the inferior angle of scapula). 15.3 External intercostal (fibres pass obliquely downward from the sharp lower border of the upper rib to the smooth upper border of the lower rib), internal intercostal (fibres run downwards and backwards from the costal groove to the upper border of the rib below) and the innermost intercostal (crosses more than one intercostal space and lies on the lateral part of the thoracic wall). 15.4 External intercostal. 15.5 The transversus thoracic group includes subcostal muscles, innermost intercostal muscles, and transversus thoracis, and is morphologically identical to the transversus abdominis inferiorly. Question 16 16.1 A- Right brachiocephalic vein, B- Left brachiocephalic vein, C- Superior vena cava, D- Ascending aorta. 16.2 (a) Costochondral joints; each rib makes a primary cartilaginous joint (no movement takes place) with its unossified costal cartilage. (b) Interchondral joints; small synovial joints between adjacent costal cartilages (6 and 7, 7 and 8, and 8 and 9). (c) Sternocostal joints; between the sternum and costal cartilages. The first rib with the manubrium is exceptional (primary cartilaginous) and it gives stability. The next six are synovial joints. 16.3 Anteriorly, the sternocostal joint has two seperate synovial joints with the manubrium and sternal body. Posteriorly, the costovertebral joints (two articular facets on each rib head articulate via small synovial joints with the demifacet of the vertebral body of its own vertebrae and the one above) and the costotransverse synovial joint (between the tubercle of the rib and the transverse process of its own vertebra).

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16.4 Atypical synovial joint (articulating surfaces are covered by fibrocartilage). It contains an intervening disc of fibrocartilage. 16.5 A symphysis between the sternal body and xiphoid process. 16.6 Primary cartilaginous joints.

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Abdomen S. Ali Mirjalili and Simon Richards

Part One: Questions Question 1 You are a surgical registrar assisting your consultant in an elective abdominal aorta repair. 1.1 Identify structure A.

A

S.A. Mirjalili (*) Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand e-mail: [email protected] S. Richards Department of General Surgery, Christchurch Hospital, Christchurch, New Zealand e-mail: [email protected] © Springer Nature Singapore Pte Ltd. and People’s Medical Publishing House 2017 S.A. Mirjalili (ed.), Anatomy for the Generic Surgical Sciences Examination (GSSE), DOI 10.1007/978-981-10-3883-9_4

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1.2 At what vertebral level does it originate? 1.3 Where does the vein associated with A drain into? 1.4 Name two of its branches? 1.5 What is the significance of this vessel in aortic aneurysm repair?

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Question 2 A 68 year old man presents to your clinic with early satiety and weight loss. Gastroscopy shows a tumour in the antrum of the stomach and biopsies confirm it as a gastric adenocarcinoma. After discussion you plan to perform a subtotal gastrectomy.

2.1 What is the blood supply of the stomach? 2.2 The local spread of this tumour may lead to lymphadenopathy in what location? 2.3 At the end of the procedure you decide to put a drain through the anterior abdominal wall in the left lower quadrant. You notice brisk arterial bleeding from the abdominal wall. What structure have you injured?

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Question 3 You are assisting your consultant in an open cholecystectomy. 3.1 Identify structure A.

A B

3.2 What is its anatomical significance? 3.3 Identify structure B. 3.4 Structure B is found in the transpyloric plane. Define this plane and name three other structures you would find at this level.

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Question 4 A 76 year old man presents with a mass in his liver. Imaging shows that it is confined to a single segment of the liver. 4.1 Identify structure A. A

B

4.2 What is unique about this segment of the liver? 4.3 Identify B and briefly describe its embryological relevance. 4.4 What structures are at risk when performing a percutaneous biopsy of this organ (name 2)?

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Question 5 A patient presents to the emergency department with severe loin to groin pain. 5.1 Identify structure A.

A

5.2 What are the sites of narrowing of structure A and what is the clinical significance of this? 5.3 Identify one key retroperitoneal vascular relation of A.

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Question 6 You are assisting your consultant who is performing a hepatectomy. 6.1 Identify A.

A

B

6.2 What is the origin of this vessel? 6.3 Identify B. What is the relation of B to A at the free edge of the lesser omentum? 6.4 A and B form the anterior boundary of the Epiploic foramen, what are the other boundaries?

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Question 7 A patient presents to the emergency department with abdominal trauma after a car accident. 7.1 Identify the organ in the picture.

7.2 What is its function? 7.3 Identify vessel A and describe its course to the organ it primarily supplies.

A

7.4 During surgical removal of this organ what structure is at risk during ligation of vessel A?

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Question 8 You perform a CT scan on a patient with severe abdominal pain. 8.1 Identify structure A. At what vertebral level does it passes into the abdominal cavity? B

C

A

8.2 Identify structure B and name 3 branches. 8.3 Identify structure C. 8.4 Name 3 tributaries of the portal vein.

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Question 9 A patient presents to your clinic with painless jaundice. 9.1 Identify structure A (be specific). B A

9.2 Name 2 other tributary vessels. 9.3 Identify structure B. 9.4 Tumours of B cause jaundice for what anatomical reason?

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Question 10 You are a urology registrar performing an orchidectomy for a testicular cancer. 10.1 Identify structure A. B A

C

10.2 Identify structure B. 10.3 Identify structure C. Tumours of C give lymphadenopathy in which location? 10.4 Abdominal hernias located medial to B are classically called what? 10.5 Name 3 other spermatic cord constituents.

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Question 11 You are a surgical trainee studying a recommended textbook prior to assisting your consultant with performing an operation for severe reflux disease. 11.1 Identify structures A and B (be specific). A B

11.2 What are the function of A and B. 11.3 What is the clinical significance of surgical division of A and B.

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Question 12 A patient presents to your practice with a vesicular rash on her right side in a band like distribution at the level of the umibilicus. 12.1 What dermatomal level is the umbilicus? 12.2 Identify structures A, B and C. C

B A

12.3 The neurovascular bundle runs between which two of the above? 12.4 What is the lower border of A? 12.5 What is the innervation of B? 12.6 What dermatomal level is the nipple?

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Question 13 You are a surgical registrar about to perform an open appendicectomy on a 32 year old male. 13.1 What structures will you divide to access the peritoneal cavity? 13.2 You are struggling to find the appendix, what landmarks may help you find it’s base? 13.3 Describe the blood supply of the appendix.

Question 14 A 27 year old male presents to the emergency department with a stab wound to the left flank. 14.1 What structures are at risk, name 3. 14.2 He is hypotensive and a FAST (Focused Assessment with Sonography in Trauma) scan shows free fluid. What is his likely injury? 14.3 You perform an emergency operation through a left subcostal incision, what layers do you divide to access the abdomen? 14.4 Post operatively he is noted to be increasingly short of breath. A chest xray shows a pneumothorax. You decide to put a chest drain in the patient. In relation to the ribs where do you place the drain?

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Part Two: Answers Question 1 1.1 Inferior Mesenteric Artery 1.2 L3 1.3 Splenic vein 1.4 Superior rectal, sigmoid and left colic arteries 1.5 It may be damaged or ligated at time of surgery leading to post-operative colonic ischaemia. Question 2 2.1 Left and right gastric, short gastrics and the left and right gastroepiploic arteries 2.2 Coeliac lymph nodes 2.3 Inferior epigastric artery Question 3 3.1 Falciform ligament 3.2 It divides the liver into left and right anatomical lobes. 3.3 Fundus of the gallbladder 3.4 The transpyloric plane is midway between the jugular notch and pubic symphysis. List any 3 of (a) Tip of 9th costal cartilages (b) Level of the pylorus (c) Fundus of the gallbladder (d) Body of the stomach (e) Lower border of L1 vertebrae (f) Spinal cord ends at conus medullaris (g) Head, neck and body of the pancreas (h) SMA leaves aorta and splenic vein runs in this plane (i) Hilum of kidneys Question 4 4.1 Caudate lobe 4.2 It has its own independent arterial and venous branches. 4.3 Ligamentum teres, remnant of the umbilical vein 4.4 Any 2 of (a) Lung (b) Bowel (c) Kidney (d) Pancreas (e) Inferior vena cava

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Question 5 5.1 Right ureter 5.2 Uteropelvic junction, vesicoureteric junction and the pelvic brim. These are sites where ureteric (kidney) stones may lodge. 5.3 Either it crosses the bifurcation of iliac vessels at the pelvic brim OR it is crossed by the gonadal vessels. Question 6 6.1 Hepatic artery 6.2 Coeliac trunk → common hepatic artery → hepatic artery 6.3 B = Bile duct. The bile duct runs lateral to the hepatic artery. 6.4 Posterior: portal vein; Superior: caudate process of caudate lobe; Inferior: first part of the duodenum Question 7 7.1 Spleen. 7.2 It is a lymphoid organ. 7.3 A = splenic artery, a branch of coeliac the trunk. It passes behind the pancreas and in lienorenal ligament to reach the spleen. 7.4 Tail of pancreas within the lienorenal ligament Question 8 8.1 Abdominal aorta, T12 8.2 Superior mesenteric artery. Any 3 arteries from (a) Inferior pancreaticoduodenal (b) Ileocolic (c) Ileal (d) Jejunal (e) Right colic (f) Middle colic 8.3 The head of the pancreas. 8.4 Any 3 veins from (a) Superior mesenteric vein (b) Splenic (c) Gastric (d) Superior pancreaticoduodenal Question 9 9.1 Left renal vein 9.2 Left gonadal, left suprarenal vein 9.3 Head of the pancreas 9.4 The distal CBD passes through the head of the pancreas and a tumour can cause compression.

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Question 10 10.1 Vas deferens 10.2 Inferior epigastric vessels 10.3 C = Testis. Lymphadenopathy can occur in the retroperitoneum 10.4 Direct inguinal hernias 10.5 Any 3 structures from (a) Arteries (testicular, cremasteric, artery to ductus) (b) Pampiniform plexus (c) Lymphatics (d) Nerves (genital branch of genitofemoral, sympathetic) (e) Obliterated processus vaginalis Question 11 11.1 Anterior and Posterior vagal trunks 11.2 Parasympathetic supply to level of splenic flexure 11.3 Hypomotility and delayed gastric emptying Question 12 12.1 T10 12.2 A = External oblique, B = Internal oblique, C = Transversus abdominus 12.3 Internal oblique and transversus abdominus 12.4 Inguinal ligament 12.5 T7-L1 12.6 T4 Question 13 13.1 Skin, subcutaneous fat, external oblique aponeurosis, internal oblique, transversus abdominus and peritoneum 13.2 Convergence of the taenia colon 13.3 Appendiceal artery from the posterior caecal artery Question 14 14.1 Any 3 from (a) Kidney (b) Spleen (c) Bowel (d) Lung (e) Pleura (f) Diaphragm 14.2 Splenic injury 14.3 Skin, subcutaneous fat, external oblique, internal oblique, transversus abdominis and peritoneum. 14.4 Just above the rib to protect the neurovascular bundle running below the lower border of the rib.

5

Pelvis S. Ali Mirjalili and Omid Yassaie

Part One: Questions Question 1 A 65 year old male presents with haematuria. The results of his CT scan are illustrated below.

S.A. Mirjalili (*) Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand e-mail: [email protected] O. Yassaie Department of Urology, Tauranga Hospital, Tauranga, New Zealand e-mail: [email protected] © Springer Nature Singapore Pte Ltd. and People’s Medical Publishing House 2017 S.A. Mirjalili (ed.), Anatomy for the Generic Surgical Sciences Examination (GSSE), DOI 10.1007/978-981-10-3883-9_5

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1.1 Describe the course of the ureter on a plain radiograph and give an example of when this may be clinically useful. 1.2 Which clinical landmarks can be used to identify the ureter intra-operatively and describe its important relations and course through the abdomen and pelvis? 1.3 What type of cells line the ureter? 1.4 What are the blood supply, lymphatic drainage and innervation of the ureter?

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Question 2 A 61 year old gentleman has a radical prostatectomy for prostate cancer. Since the operation he has developed numbness in his medial thigh. 2.1 Name structures A, B, C and D.

D B

C A

2.2 What are the anatomical relations of the prostate? 2.3 Name the structure which has been damaged. What are its innervation, course and relation to its vascular pedicle in the pelvis?

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Question 3 A 21 year old male presents after sexual intercourse with sudden detumescence, a snapping sensation and the physical appearance illustrated in the accompanying diagram.

3.1 What anatomical structure has been injured? 3.2 Name labels A, B, C, D and E.

E D

C B A 3.3 Where would you expect the bruising to extend to and how would you explain this anatomically?

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Question 4 A 54 year old male presents with pain on moving his hip. He is tender in the right lower quadrant. He has an INR of 4.5 and is on warfarin for atrial fibrillation. A CT scan is shown below.

4.1 What is the diagnosis? Identify the muscle affected. 4.2 What are the attachments of this muscle and what is its main action? 4.3 What is its innervation? 4.4 Which nerve(s) would you expect to lie directly on top of this muscle and which arise from its lateral and medial aspects?

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Question 5 You are consenting a patient with renal cancer for a nephrectomy and you relate the possible complications to the surgical anatomy of the kidney. 5.1 Name the posterior relations of the kidney 5.2 Name the anterior relations of the kidney 5.3 What structures make up the renal hilum and how are they normally orientated? 5.4 What are the structures labeled A and what are their relations to the kidney? What is their innervation and blood supply? What are the layers of this gland and what do they secrete? A

B

5.5 What is the structure labeled B? Where does it begin, what are its branches and where does it end?

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Question 6 A 75 year old has a staging CT scan for his left sided renal cancer.

6.1 What is the variant in this CT scan? 6.2 At what level does it normally commence and leave the abdomen/pelvis?

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Question 7 A 78 year old female presents with stress urinary incontinence. She was advised to strengthen her pelvic floor muscles. 7.1 Name muscle A. What are its attachments and innervation? What structures pass superior and inferior to it?

A

B

7.2 Name muscle B. What are its attachments and innervation? 7.3 What muscles make up the pelvic floor and what are their innervations?

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Question 8 A 68 year old gentleman presents with fresh rectal bleeding. He has a colonoscopy which demonstrates a malignancy in his rectum. He is wait listed for an anterior resection.

8.1 How is the transition between the sigmoid colon, rectum and anus defined anatomically? 8.2 Describe the peritoneal relations of the rectum.

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Question 9 A 78 year old smoker has a cystoscopy for haematuria. 9.1 What are the structures, labeled as A, you would try to identify first in order to orientate yourself.

A

9.2 How far apart would you expect to see these structures in the non-distended and distended state of the bladder? 9.3 What is the name given to the area bound by the two ureteric orifices and the internal urethral orifices? 9.4 Describe the blood supply, lymphatic drainage and nerve supply of the bladder. 9.5 How long is the male urethra and what divisions are there? 9.6 Where are the narrow points of the urethra?

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Question 10 This intraoperative photo was taken during a bulbar urethroplasty. 10.1 Name the borders of the urogenital triangle. 10.2 Name the muscle A which is retracted by the skin hook and usually covers the corpus

A

B

10.3 Name the structure B and which other structures attach here? 10.4 Name the layers you would expect to dissect though when approaching the bulbar urethra for a urethroplasty.

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Question 11 A 48 year old man presents with a perianal abscess which he had drained by a junior registrar. Following the procedure he was incontinent of faeces.

11.1 Describe the anal sphincter mechanism. 11.2 What are the borders of the ischio-anal fossa?

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Part Two: Answers Question 1 1.1 The ureters originate from the renal hilum at approximately L1/L2. They course down just medial to the tips of the transverse processes. At the pelvic brim they overlie the sacroiliac joints. The course continues down towards the ischial spines where they turn medially towards the bladder. This is clinically relevant as it provides clinicians with a ‘roadmap’ of where to look to identify potential stones in the urinary tract on plain film KUB (kidney, ureter and bladder) X-rays. 1.2 The important intraoperative anatomical landmarks are the bifurcation of the common iliac arteries (over the sacro-iliac joint at the pelvic brim) as well as the apex of the sigmoid mesocolon for the left ureter. It can be distinguished from other structures by gently pinching it with forceps, it typically reacts with some peristaltic activity. The ureter is a 25 cm tubular, white, retroperitoneal structure which drains urine, produced in the kidney, for storage and expulsion in the bladder. The bladder functions as an organ for storage and expulsion of urine. The ureter is the most posterior structure within the renal hilum and ends as a tunneled ureteric orifice, terminating at the trigone in the bladder. The posterior relations of the ureter in the abdomen are the psoas muscle, the genito-­femoral nerve and the bifurcation of the common iliac artery. Within the pelvis, the ureter crosses anterior to the internal iliac artery, obturator nerve, superior vesical artery (obliterated umbilical artery) and the obturator artery and vein. The anterior relations of the right ureter are the duodenum proximally followed by gonadal vessels, the root of the small bowel mesentery, and the superior ­mesenteric artery (as well as its right colic/ileocolic branches). The anterior relations of the left ureter are the gonadal vessels, left colic vessels and the apex of the sigmoid mesocolon. Within the male pelvis the ductus deferens crosses anterior to the ureter. The ureter enters the bladder just superior to the tips of the seminal vesicles. In the female pelvis the ureter passes through the base of the broad ligament. The uterine artery initially lies alongside the ureter before crossing anterior to it. The ureter then passes from the broad ligament anteriorly towards the ureteric orifice in the bladder. The medial relation of the left ureter is the inferior mesenteric pedicle. 1.3 Transitional cells. These cells form a “waterproof” coating which lines the urinary tract except for the navicular fossa of the urethra. 1.4 Blood supply: The upper portion is supplied by ureteric branches off the renal arteries. The middle portion is supplied by the gonadal vessels and the common iliac vessels. The inferior portion in the pelvis is supplied by the superior and inferior vesical arteries as well as the middle rectal artery. These vessels form an anastomosing network within the adventitia which surrounds the ureter. This is clinically significant as proximally the blood supply of the ureter is predominantly medial while distally the supply is mostly lateral. When mobilizing the ureter it should preferentially be towards the blood supply. Adventitia should be preserved as much as possible.

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Lymphatics: The lymphatics follow the arteries. Therefore the abdominal portion of the ureter drains in to the para-aortic nodes and the pelvic portion drains into the nodes on the pelvic sidewall. Innervation: The ureter is supplied by the autonomic nervous system. Sympathetics arise from the sympathetic trunk via the coeliac ganglia and the hypogastric plexus. The parasympathetic supply arises from the pelvic splanchnic nerves (S2-S4). The exact function of these nerves is unknown. Pain travels along the sympathetics. Question 2 2.1 A: Femoral Nerve, B: Psoas Major C: External iliac artery D: Obturator nerve 2.2 The prostate is a glandular structure, size 4*3*2 cm which provides 30% of the seminal volume. The base of the prostate is the upper surface and lies next to the bladder. The apex of the prostate can be considered to be the “tip” of the prostate, this is intimately related to the membranous urethra and the urogenital diaphragm on which the prostate lies. The infero-lateral surfaces of the prostate lie on the levator ani muscles of the pelvic floor. The anterior prostate lies in the retro-­pubic space, the prostate has some firm attachments on this surface to the pubis by the pubo-prostatic ligaments. The posterior prostate lies on the rectum, separated by denonvilliers fascia. The prostatic urethra traverses through the middle of the prostate. 2.3 The obturator nerve has been injured. The obturator nerve is formed by the anterior divisions of the second, third and fourth lumbar nerves within the psoas muscle and pierces the medial border of psoas. It crosses the pelvic brim just medial to the sacro-iliac joint and runs into the pelvis between the internal iliac vessels and the obturator internus fascia. The nerve then passes between the internal and external iliac vessels onto the side wall of the pelvis. The nerve lies above the obturator artery and vein. Question 3 3.1 The tunica albuginea has been damaged. It surrounds the corpora cavernosa and can be torn in the erect state. 3.2 A: Urethra, B: Corpus spongiosum, C: Corpus cavernosum, D: Deep penile artery and E: Dorsal penile artery 3.3 This depends on whether the Buck’s fascia is involved. In the majority of cases, the Buck’s fasica remains intact therefore the bruising remains limited to the shaft of the penis. If the Bucks fascia is injured however then the bruising may spread into the perineum/scrotum (limited by the superficial Colles fascia joining the posterior border of the perineal membrane) and anterior abdominal wall. Question 4 4.1 This patient has a retroperitoneal haematoma which is irritating the adjacent psoas muscle. 4.2 Psoas arises from the intervertebral discs above the fifth lumbar vertebrae as well as the adjoining parts of the vertebrae bodies. It also has attachments to some fibrous arches that span the concavities of L1-L4 and their transverse processes.

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Psoas passes beneath the inguinal ligament and attaches to the lesser trochanter of the femur. Its main action is to flex the hip. It may also aid in lateral flexion of the vertebral column. 4.3 L1-L3, mostly L2. 4.4 Directly on top: The genitofemoral nerve. Exiting psoas laterally: The iliohypogastric, ilioinguinal, lateral femoral cutaneous and femoral nerves. Exiting psoas medially: The obturator nerve and lumbo-sacral trunk. Question 5 5.1 Most of the kidneys lie on the diaphragm and the quadratus lumborum muscles. Medially there is an overlap with the psoas muscle while laterally there is overlap with the transversus abdominis muscle. The costodiaphragmatic recess of the pleura also lies posteriorly. The subcostal neurovascular bundle and the iliohypogastric and ilioinguinal nerves also run behind the kidney. 5.2 The anterior relations are asymmetrical. The kidneys are retroperitoneal structures, therefore you can think of the peritoneum as an “anterior” structure with several structures “pushing it away”. The hilum on the right is separated from the peritoneum by the second part of the duodenum while the left side is separated by the tail of the pancreas. The hepatic flexure and splenic flexure of the colon lie anterior to the lateral lower poles of the right and left kidney respectively. The medial lower pole is traversed by the ascending branch of the right and left colic arteries on the right and left kidneys respectively. The upper portion of the kidney is covered directly by peritoneum on both sides. On the right side, the hepato-renal pouch lies in front while the lesser sac lies anteriorly on the left side. 5.3 The renal hilum is made up of the renal vein, renal artery and renal pelvis. The renal vein lies anteriorly, remember this by the vein being “vain” and thus wanting to be at the front. The artery lies behind the vein and the renal pelvis is the most posterior structure. 5.4 A: the supra-renal glands (adrenal glands). The right side is pyramidal in shape and lies directly superior to the kidney nested between the right crus and IVC. The left gland is more crescentric in shape and lies on the medial aspect of the left kidney just above the hilum. Innervations: The adrenal glands are supplied by pre ganglionic sympathetic fibers via the splanchnic nerve which passes through the aortic and renal plexus. Vascular supply: Arterial supply comes from three sources, inferior phrenic, renal artery and aorta. In contrast, there is only one vein. The right gland drains directly into the IVC, the left gland drains into the renal vein. Layers: The adrenal gland is made up of the cortex on the outside and the medulla on the inside. The cortex is made up of the zona gloumerulosa, zona fasiculata, and zona reticularis which secrete aldosterone, glucocorticoids and androgens respectively. Remember these layers by GFR (like glomerular filtration rate). The medulla secretes noraderelinae.

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V- B: The abdominal aorta, it is the direct continuation of the thoracic aorta once it has passed behind the median arcuate ligament. The abdominal aorta ends at the L4 vertebral body where it bifurcates into the two common iliac arteries. Branches: It is easiest to remember the branches of the abdominal aorta by dividing them into three groups- single branches to the gut, paired vessels to abdominal viscera and paired branches to the abdominal wall. Single branches to the gut – Coeliac artery, Superior mesenteric artery, Inferior Mesenteric Artery. Paired branches to viscera – Supra-renal arteries, Renal arteries, Gonadal Arteries. Paired branches to abdominal wall – Inferior Phrenic Arteries, Lumbar Arteries (pass behind the sympathetic trunk), and Iliolumbar Artery. The final terminal branch arising from the aorta is the Median sacral artery. Question 6 6.1 The IVC on this scan is on the left side of the aorta, normally the IVC lies on the right side of the aorta. 6.2 The IVC is normally formed in the pelvis by the unification of the two common iliac veins at the level of L5. The IVC normally leaves the abdomen by piercing the central tendon of the diaphragm at the level of T8. Question 7 7.1 A: Piriformis. It arises from the sacrum and adjoining lateral mass. The muscle then passes through the greater sciatic foramen and inserts into the apex of the greater trochanter. It is supplied by the anterior rami of S1 and S2. Above – Superior gluteal nerve and vessels. Below – Inferior gluteal nerve and vessels, pudendal nerve and vessels, nerve to obturator internus and the sciatic nerve with the posterior femoral cutaneous nerve running superficial to it and the nerve to quadratus femoris running deep to it. 7.2 B: Obturator internus. It arises from the rim of the obturator foramen and the obturator membrane, a tough membrane, which lies on the foramen. Superiorly its attachment goes up to the pelvic brim. It converges on the lesser sciatic foramen and inserts into the medial aspect of the greater trochanter. It is innervated by the nerve to obturator internus. 7.3 The pelvic floor is made up of coccygeus and levator ani. Coccygeus: arises from the ischial spine and fans out to insert into the side of the coccyx and the lowest part of the sacrum. It is innervated by the perineal branches of S4/S5. Levator ani: consists of two parts which share a common origin from the arcus tendineus (a thickened fibrous band which runs from the ischial spine to the pubic symphysis). Iliococcygeus: arises from the posterior half of the arcus tendineus and the ischial spine. It inserts into the side of the coccyx and the ano-coccygeal raphe (which runs from the coccyx to the junction of the anal canal and rectum).

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Pubococcygeus: arises from the anterior half of the arcus tendineus and the pubic symphysis. The bulk of the muscle is composed of the “pubococcygeus proper” which attaches to the anococcygeal raphe and ligament. The more anterior part of the muscle arises from the periosteum of the pubis. These fibers swing around the rectum and join with fibers from the posterior external anal sphincter as well as fibers from the opposite side (puborectalis). Several other “u” slings which pass around other pelvic organs are the levator prostatae and pubovaginalis which wrap around the prostate and vagina respectively. The nerve supply is via the perineal branches of S3 and S4.

Piriformis muscle Coccygeus muscle

Obturator internus

Anococcygeal ligament

Tendinous arch (white line) Obturator canal

Sacrospinous ligament (cut) Iliococcygeus Levator ani

Anal aperture

Pubococcygeus Puborectalis Urogenital hiatus

Question 8 8.1 There is no change in structure between the sigmoid colon and the rectum. The sigmoid colon has a mesentery where the rectum does not. The transition is normally at the level of S3. The anus begins where the muscular coats of the rectum are replaced by circular sphincters. The pubo-rectalis forms a palpable landmark here where it slings around the junction, which lies 3 cm from the cutaneous margin and 5 cm anterior to the coccyx. 8.2 The upper part of the rectum is covered by peritoneum on the front and sides. The middle third is covered only on the front where the inferior third is below the peritoneal reflection and has no peritoneal covering.

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Question 9 9.1 A: Ureteric orifices. These are used in order to orientate oneself when performing a cystoscopy. 9.2 The urteric orifices are normally 2.5 cm apart in a non-distended bladder and 5 cm apart in a distended bladder. They are separated by a ridge called the inter-­ ureteric bar. 9.3 The trigone.

Muscle coat of the rectum

Levator ani Anal coloumn Anal sinus External anal sphincter Anal valve Pectinate line Internal anal sphincter

Anal pecten

Anocutaneous line Anal aperture

9.4 Blood supply: The majority of the blood supply arises from the superior and inferior vesical arteries. The bladder also receives some blood from the obturator, inferior gluteal, uterine and vaginal arteries. Lymphatics: The lymphatics follow the arteries, into the internal and external iliac nodes.

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Innervation: The nerve supply is both parasympathetic and sympathetic. Remember parasympathetic to Pee. The parasympathetics also sense distension. These supply the bladder via the pelvic splanchnic nerves. The sympathetics arise from L1 and L2 via the superior hypogastric and pelvic plexuses, they are most likely inhibitory to the detrusor muscle. They also supply the trigone and function to contract the internal urethral sphincter. 9.5 The male urethra is 20 cm in length and can be divided into anterior and posterior parts. The anterior urethra is made up of the penile and bulbar urethra while the posterior urethra is composed of the membranous and prostatic urethra. 9.6 The narrowings are at the bladder neck, membranous urethra, proximal end of the navicular fossa and lastly at the external meatus. The dilated parts are at the prostatic urethra, bulbar urethra and at the navicular fossa. Question 10 10.1 The urogenital triangle is anterior to a line connecting the two ischial tuberosities and the pubic symphysis in front. 10.2 A: The bulbospongiosus muscle. 10.3 B: The perineal body/central perineal tendon. This is an elongated fibromuscular membrane which lies just posterior to the perineal membrane and just anterior to the anus. It attaches to both of these structures as well as the rectovesical or rectovaginal septum. Several muscles also attach to the perineal body. Both the external anal and external urethral sphincters attach to it, levator prostatae (or pubovaginalis), levator ani, bulbospongiosus and the superficial and the deep transverse perinea also attach. Perineal body Ureters Opening of ureters

Trigone

Urethra

Internal urethral orifice

10.4 Firstly skin and subcutaneous tissue. The next layer is the superficial perineal fascia (of Colles) which is the continuation of Scarpas fascia from the abdominal wall. This is the superficial perineal pouch where the bulbospongiosus

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muscles arises. The muscle lies on the tough perineal membrane. Deep to this lies the deep perineal pouch (you do not need to enter this space during this surgery when accessing the urethra). Once the bulbospongiosus muscle is exposed, it is dissected off the corpora spongiosus. This is then incised to expose the urethra. Question 11 11.1  The sphincters can be divided into internal and external sphincter mechanisms: Internal – composed of visceral muscle. A thickened continuation of the inner circular layer of rectal muscle. External – composed of skeletal muscle. The deep part blends with the puborectalis part of levator ani. This is referred to as the anorectal ring. The superficial part is an elliptical shape and is continuous with the perineal body anteriorly and the coccyx posteriorly. Finally, the subcutaneous portion is a circular muscle whose lower end lies just below the bottom of the internal sphincter. Sphincters are also assisted by muscles around the anus (e.g., the puborectalis forms a sling around the junction of the rectum and the anus to make a right angle, this aids with continence). Anal canal and its internal and external sphincters

Rectum

Obturator internus Pudendal nerve Levator ani

Ischioanal fossa External anal sphincter

Internal pudendal artery Internal anal sphincter

11.2 The ischioanal fossa is a wedge shaped fossa lateral to the anal canal where abscesses may occur. The base of the fossa is the skin of the perineum. The anal canal and levator ani muscles form the medial border. The lateral border is formed by the ischial tuberosity inferiorly and the obturator internus above. The anterior boundary is the posterior border of the perineal body and the urogenital diaphragm. The posterior boundary is the sacro-tuberous ligament overlapped by the gluteus maximus.

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Pubic symphysis Pubic tubercle Ischiocavernous muscle Bulbospongiosus muscle

Superficial transverse perineal muscle

Perineal body External anal sphincter

Ischioanal fossa

6

Head and Neck S. Ali Mirjalili

Part One: Questions Question 1 You are assisting your consultant during a lymph node biopsy of the posterior triangle of the neck.

1.1 Identify the structure indicated by the probe? 1.2 What consequences will there be for the patient as a result of injury to this structure?

S.A. Mirjalili Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand e-mail: [email protected] © Springer Nature Singapore Pte Ltd. and People’s Medical Publishing House 2017 S.A. Mirjalili (ed.), Anatomy for the Generic Surgical Sciences Examination (GSSE), DOI 10.1007/978-981-10-3883-9_6

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1.3 What is the course of this structure through the neck? 1.4 Which surgical procedure most commonly injures this structure?

Question 2 A 65 year old man presents with lymphadenopathy secondary to a head and neck squamous cell carcinoma and after multidiciplinary team discussion the plan is to perform a radical neck dissection.

2.1 Identify the structure indicated by the probe? 2.2 What muscle(s) lie immediately superficial to this structure? 2.3 What is the course of this structure in the neck? 2.4 What is the function of this structure?

6  Head and Neck

Question 3 You are a final year trainee undertaking a submandibular gland excision.

3.1 Identify the structure indicated by the probe? 3.2 What is its origin? 3.3 What is its function?

Question 4 You are performing surgery in the neck to gain central venous access.

4.1 Identify the structure indicated by the probe? 4.2 Describe in detail all terminal sensory branches of the cervical plexus?

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Question 5 A 38 year old woman presents with a skin lesion over the lower border of the mandible.

5.1 Identify the structure indicated by the forceps? 5.2 What is the surface anatomy of this structure? 5.3 Identify the structure that the white arrow is pointing to? 5.4 What is the course of the structure indicated by the white arrow in the neck?

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Question 6 You are a surgical registrar assisting your consultant in submandibular gland surgery.

6.1 Identify the structure indicated by the probe? 6.2 What nerve innervates this structure? 6.3 Name the suprahyoid muscles?

Question 7 You are a surgical registrar assisting your consultant in radical neck dissection in the posterior triangle of the neck.

7.1 Identify the structure indicated by the forceps? 7.2 What nerve innervates this structure? 7.3 Name the infrahyoid muscles?

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Question 8 A 72 year old man presents with a mass on the lateral side of his face overlying the ramus of the mandible.

8.1 Identify the structure indicated by the probe? 8.2 What neurovascular structures are running through it, and how are they arranged in relation to one another?

Question 9 A 44 year old man presents with dyspnea after central vein catheterization.

9.1 Identify the structure indicated by the probe? 9.2 What nerve roots contribute to this structure? 9.3 Describe the course of this structure through the root of the neck?

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Question 10 A 78 year old man presents with a mass on the lower border of the body of the mandible.

10.1 Identify the structure indicated by the probe? 10.2 Describe the structures which cross it? 10.3 During a procedure to remove it, name 3 nerves which are at risk of being injured?

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Question 11 You are performing a total thyroidectomy for papillary thyroid carcinoma.

11.1 Identify the structure indicated by the probe? 11.2 What is the origin of this structure? 11.3 What is the function of this structure?

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Question 12 A 56 year old woman presents with dysphonia after subtotal thyroidectomy.

12.1 Identify the structure indicated by the probe? 12.2 Describe the course of this structure through the neck?

Question 13 A 28 year old woman presents with an anterior cervical neck mass and you plan is to perform a FNA (fine needle aspiration). A

B C

13.1 Identify the structure labelled A, B and C? 13.2 Describe the blood supply, venous and lymphatic drainage of A?

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Question 14 Following a motor accident, a young man is unable to empty his bladder and bowel.

A

B C D

14.1 Identify the parts labelled A, B, C and D? 14.2 How many spinal nerves are there? 14.3 Which region of the spine is this vertebra from? 14.4 Which characteristics help to identify it?

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Part Two: Answers Question 1 1.1 The spinal accessory nerve [CNXI] 1.2 If this structure is damaged the patient will be unable to shrug their ipsilateral shoulder or raise their ipsilateral arm above their head. This is because the spinal accessory nerve innervates trapezius and sternocleidomastoid. 1.3 The spinal accessory nerve leaves the skull through the middle part of the jugular foramen posterior to CNX. It then runs posterolaterally, either medial or lateral to the internal jugular vein. It then finally crosses the transverse process of the atlas, and passes medial to the styloid process and posterior belly of digastric to perforate the sternocleidomastoid muscle and reach the posterior triangle of the neck. 1.4 Posterior triangle lymph node biopsy. Question 2 2.1 The hypoglossal nerve [CNXII] 2.2 The posterior belly of digastric. 2.3 The hypoglossal nerve leaves the skull through the hypoglossal foramen. It then passes between the internal carotid artery and internal jugular vein and crosses three arteries (occipital, external carotid and lingual arteries). It lies deep to the posterior belly of digastric to reach the tongue. 2.4 The intrinsic and extrinsic muscles of the tongue are innervated by the hypoglossal nerve; except palatoglossus. Question 3 3.1 The facial artery. 3.2 The facial artery is the 3rd anterior branch of the external carotid artery. 3.3 The facial artery supplies structures in the face including the: palatine tonsil, soft palate, mandible, anterior belly of digastric and mylohyoid. Question 4 4.1 The great auricular nerve 4.2 The cervical plexus is formed by the anterior rami of cervical nerves C1 to C4. Its cutaneous branches are visible in the posterior triangle. They emerge from beneath the posterior border of sternocleidomastoid muscle and are the: lesser occipital nerve, great auricular nerve, transverse cervical nerve and the supraclavicular nerve. The transverse cervical nerve runs in the anterior triangle. The lesser occipital nerve is a slender branch that hooks around the accessory nerve. The great auricular nerve is a larger trunk that supplies the skin over the side of the face. The supraclavicular nerve emerges at the posterior border of the sternocleidomastoid and divides into three main groups: a medial branch which supplies the skin down to the sternal angle, an intermediate branch which supplies as far down as the anterior axial line and a lateral branch which supplies the skin halfway down the deltoid and the posterior aspect of the shoulder.

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Question 5 5.1 The marginal mandibular nerve. 5.2 The marginal mandibular nerve runs along the lower border of the mandible. Due to its superficial course and variable distribution it is often at risk of injury during surgical procedures. It is thus advisable to make any incision at least 3–4 cm below the inferior border of the mandible to avoid injury to this nerve. 5.3 The facial nerve. 5.4 The facial nerve exits the skull through the stylomastoid foramen and then immediately gives off the posterior auricular nerve to supply the occipital part of occipitofrontalis. The next branch which comes off the facial nerve innervates the posterior belly of digastric and stylohyoid muscles. The facial nerve then enters the posteromedial surface of the parotid gland and divides into an upper temporozygomatic and lower cervicofacial branch. The branching pattern of the facial nerve is variable as it runs through the superficial part of the parotid gland. Five branches eventually emerge from the anterior border of the parotid gland: temporal, zygomatic, buccal, marginal mandibular and cervical branches. Question 6 6.1 The mylohyoid muscle. 6.2 The mylohyoid nerve. 6.3 Geniohyoid, mylohyoid, stylohyoid and the anterior and posterior bellies of the digastric muscle. Question 7 7.1 The omohyoid muscle. 7.2 The ansa cervicalis (C1, C2 and C3). 7.3 Omohyoid, sternohyoid, thyrohyoid and sternothyroid. Question 8 8.1 The parotid gland. 8.2 From deep to superficial the structures that run through the parotid gland are the: external carotid artery, retromandibular vein and facial nerve. Question 9 9.1 The phrenic nerve. 9.2 C3, C4 and C5. 9.3 It passes down over the anterior scalene muscle, across the dome of the pleura and behind the subclavian vein. Question 10 10.1 The submandibular gland. 10.2 There are a number of structures running across the gland; facial vein, facial artery and lymph nodes. The mylohyoid, hyoglossus and posterior belly of digastric muscles are also closely associated with the submandibular gland. 10.3 The marginal mandibular branch of the facial nerve, lingual nerve and hypoglossal nerve.

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Question 11 11.1 The superior thyroid artery. 11.2 The superior thyroid artery is the first anterior branch of the external carotid artery. 11.3 This artery supplies the upper pole of the thyroid, as well as giving off sternocleidomastoid and superior laryngeal branches. Question 12 12.1 The vagus nerve. 12.2 The vagus nerve leaves the skull through the jugular foramen between CN IX and XI. It travels downward in the carotid sheath, between the internal carotid artery and internal jugular vein. At the root of the neck it passes in front of the subclavian artery and behind the subclavian vein to enter the mediastinum. Question 13 13.1 A: Thyroid gland, B: Sternocleidomastoid, C: Internal jugular vein 13.2 The blood supply is from the superior and inferior thyroid arteries. The venous drainage is via three veins; 1- superior thyroid vein, 2- middle thyroid vein and 3- inferior thyroid vein. Lymph drainage follows arteries; the upper pole to the anterosuperior group, and lower pole to the posteroinferior group of the deep cervical nodes Question 14 14.1 A: Body, B: Pedicle, C: Transverse process, D: Lamina 14.2 31 pairs 14.3 Lumbar vertebra (L4) 14.4 Characterised by their large size, no facets for articulation with ribs, the transverse processes are generally thin and long, the vertebral body is cylindrical and the vertebral foramen is triangular in shape and larger than the thoracic vertebrae

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Surgical Embryology Spencer Beasley and Kiarash Taghavi

Part One: Questions Question 1 Fig. 7.1  Clinical photograph of a fetus with spina bifida

S. Beasley Department of Paediatric Surgery, Christchurch Hospital, Christchurch, New Zealand Department of Surgery, University of Otago, Christchurch, New Zealand e-mail: [email protected] K. Taghavi (*) Department of Paediatric Surgery, Starship Hospital, Christchurch, New Zealand e-mail: [email protected] © Springer Nature Singapore Pte Ltd. and People’s Medical Publishing House 2017 S.A. Mirjalili (ed.), Anatomy for the Generic Surgical Sciences Examination (GSSE), DOI 10.1007/978-981-10-3883-9_7

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A

C

Fig. 7.2  The above schematic cross-sectional diagram illustrates the process of neurulation that begins in the third week of gestation

1.1 When does a human embryo become a fetus? 1.2 Label the structures A, B and C. 1.3 What process does the term “neurulation” describe? 1.4 How is neurulation achieved, and at what stage of gestation does it happen? 1.5 What do neural crest cells differentiate into? 1.6 Name at least two clinical conditions that are directly attributable to aberrant neural crest cell development. Further Reading Betters E, Liu Y, Kjaeldgaard A, Sundström E, García-Castro MI. Analysis of early human neural crest development. Dev Biol. 2010;344(2):578–92. Greene ND, Copp AJ. Development of the vertebrate central nervous system: formation of the neural tube. Prenat Diagn. 2009;29(4):303–11. Huang X, Saint-Jeannet JP. Induction of the neural crest and the opportunities of life on the edge. Dev Biol. 2004;275(1):1–11.

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Question 2 Fig. 7.3  The human embryo has four pairs of pharyngeal pouches. This figure is a schematic diagram of the right pharyngeal pouches in the fifth week of gestation

Pharyngeal pouches

Arch 1 External auditory meatus

1 Arch 2 2 Arch 3 3

Arch 4

4

2.1 Name the derivatives of each of the pharyngeal pouches labelled above. 2.2 Describe the process of descent of the thyroid gland. 2.3 Describe the development of the superior and inferior parathyroid glands, and their ultimate location. 2.4 What pharyngeal cleft causes the most frequently encountered abnormalities? 2.5 Between which two arteries can a second pharyngeal cleft anomaly pass, and where does it ultimately terminate? Where does its external opening lie? Recommended Reading Grevellec A, Tucker AS. The pharyngeal pouches and clefts: development, evolution, structure and derivatives. Semin Cell Dev Biol. 2010;21(3):325–32. Mohebati A, Shaha A. Anatomy of thyroid and parathyroid glands and neurovascular relations. Clin Anat. 2012;25(1):19–31. Waldhausen JHT. Branchial cleft and arch anomalies in children. Semin Pediatr Surg. 2006;15(2):64–9.

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Question 3 Fig. 7.4  Clinical photograph of a fetus with a left congenital diaphragmatic hernia. Note herniation of the left lobe of the liver and bowel in the left hemithorax displacing the heart to the right

3.1 What are the eponymous names and specific locations of the two most common types of congenital diaphragmatic herniae? 3.2 Where does the septum transversum originate and what does it form? 3.3 From where does the mature diaphragm gain its musculature? Recommended Reading Babiuk RP, Greer JJ. Diaphragm defects occur in a CDH hernia model independently of myogenesis and lung formation. Am J Physiol Lung Cell Mol Physiol. 2002;283(6):L1310–4. Mayer S, Metzger R, Kluth D. The embryology of the diaphragm. Semin Pediatr Surg. 2011;20(3):161–9. Veenma DC, de Klein A, Tibboel D. Developmental and genetic aspects of congenital diaphragmatic hernia. Pediatr pulmonol. 2012;47(6):534–45.

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Question 4 Fig. 7.5 Clinical photograph of oesophageal atresia with a fistula from the carina that connects with the lower part of the oesophagus, called a distal tracheo-oesophageal fistula. Note in this dissection the posterior wall of trachea and oesophagus have both been opened

Tracheo-esophageal fistula

4.1 What structure controls development of the foregut? 4.2 What is the cellular process of tracheo-oesophageal separation? 4.3 What genes control tracheo-oesophageal separation? 4.4 From what does a cervical rib develop? 4.5 List the five named histological stages of normal lung development. 4.6 When does alveolar maturation and development complete? Recommended Reading Metzger R, Wachowiak R, Kluth D. Embryology of the early foregut. Semin Pediatr Surg. 2011;20(3):136–44. Mullassery D, Smith NP. Lung development. Semin Pediatr Surg. 2015;24(4):152–5. Williams AK, Quan QB, Beasley SW. Three-dimensional imaging clarifies the process of tracheoesophageal separation in the rat. J Pediatr Surg. 2003;38(2):173–7.

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Question 5 Fig. 7.6  This photograph shows a sagittal section through the fetal liver showing major venous structures. E – umbilical vein, D – portal sinus

5.1 Name the cardiac chamber A and the venous structures B and C. 5.2 Name two pathways in fetal circulation that allow blood to bypass the lungs. 5.3 The ligamentum arteriosum connects which structures? 5.4 The ligamentum arteriosum is intimately related to what nerve? 5.5 What does the truncus arteriosus form? Recommended Reading Kiserud T. Physiology of the fetal circulation. Semin Fetal Neonatal Med. 2005; 10(6):493–503. Kussman BD, Holzman RS. Cardiac embryology: understanding congenital heart disease for the noncardiac anesthesiologist. Semin Cardiothoracic Vasc Anesth. 2001;5(1):2–20. Reynolds P. Fetal to neonatal transition–how does it take place? Surgery (Oxford). 2013;31(3):106–9.

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Question 6 Fig. 7.7 Clinical photograph of gastroschisis with malrotation with a large segment of necrotic small intestine

6.1 During what week of gestation does the rapidly elongating midgut herniate through the umbilicus? 6.2 When in gestation does the intestine normally return to the abdominal cavity? 6.3 What is the net magnitude (number of degrees) and direction (clockwise or anticlockwise) of normal rotation? 6.4 If the midgut fails to return to the peritoneal cavity what pathology might result? 6.5 What are the five characteristic abnormalities of the Pentalogy of Cantrell? Recommended Resources Dr. Robert Acland, University of Louisville. Rotation of the midgut. Available from: http://www.youtube.com/watch?v=AscKR_cQExY. Kim WK, Kim H, Ahn DH, Kim MH, Park HW. Timetable for intestinal rotation in staged human embryos and fetuses. Birth defects research Part A. Clin Mol Teratol. 2003;67(11):941–5. Sadler TW, Feldkamp ML. The embryology of body wall closure: relevance to gastroschisis and other ventral body wall defects. Am J Med Genet Part C Semin Med Genet. 2008;148(3):180–5.

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Question 7 Fig. 7.8 Clinical photograph illustrating the foregut structures

7.1 Name structures A and B. 7.2 Does the spleen develop within the ventral or dorsal mesogastrium? 7.3 Describe the embryology of the pancreas. Recommended Reading Tadokoro, Hiroyuki, Masaru Takase, and Bunsei Nobukawa. Development and congenital anomalies of the pancreas. Anatomy research international, 2011.

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Question 8 a

b

c

Fig. 7.9  Schematic representation of some of the abnormalities of the vitellointestinal duct

8.1 What structures does the umbilical ring contain during fetal life? 8.2 Umbilical discharge immediately after birth could be the consequence of one of what two unrelated conditions, and what is the nature of the discharge of each? 8.3 Name the abnormalities illustrated in a, b and c. 8.4 Name all the peritoneal folds emanating from the umbilicus in adult life and their contents. Recommended Reading Robinson JN, Abuhamad AZ. Abdominal wall and umbilical cord anomalies. Clin Perinatol. 2000;27:947–78, ix. Vermeij-Keers C, Hartwig NG, van der Werff JF. Embryonic development of the ventral body wall and its congenital malformations. Semin Pediatr Surg. 1996;5:82–9.

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Question 9

Fig. 7.10  Clinical photograph of bilateral multicystic dysplastic kidneys

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9.1 Name the three major paired divisions of mesoderm and list their derivatives. 9.2 Name the temporal sequence of structures that are involved in the formation of the kidney. 9.3 How does the ureter form? 9.4 What does the “Weigert-Meyer” rule state? Recommended Reading Ichikawa I, Kuwayama F, Pope JC, Stephens FD, Miyazaki Y. Paradigm shift from classic anatomic theories to contemporary cell biological views of CAKUT. Kidney Int. 2002;61(3):889–98. Nigam SK, Shah MM. How does the ureteric bud branch? J Am Soc Nephrol. 2009;20(7):1465–9.

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Question 10 Fig. 7.11  Clinical photograph of the developing urogenital system on the left side in a male fetus

10.1 Name structures A and B. 10.2 What does the testis develop from? 10.3 What well described gene on the Y chromosome is responsible for sexual differentiation. 10.4 What are the two named phases of testicular descent? 10.5 At what gestational ages does each phase of testicular descent occur? 10.6 What is homologous to the gubernaculum in the female? 10.7 What layers are incised during scrotal exploration to assess the testis (and which abdominal wall layers are these contiguous with)? Recommended Reading Hutson JM. Journal of Pediatric Surgery-Sponsored Fred McLoed Lecture. Undescended testis: the underlying mechanisms and the effects on germ cells that cause infertility and cancer. J Pediatr Surg. 2013;48(5):903–8. Hutson JM, Grover SR, O’Connell M, Pennell SD. Malformation syndromes associated with disorders of sex development. Nat Rev Endocrinol. 2014;10(8):476–87.

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Question 11

Fig. 7.12  Photograph of a bicornuate uterus

11.1 What do the paramesonephric ducts (or Müllerian ducts) develop into in females and males? 11.2 What do the mesonephric ducts (or Wolffian ducts) develop into in males and females? 11.3 What does the lower vagina develop from? 11.4 What abnormality results from the anomalous “zipping up” of the urethral plate in males? Recommended Reading Hadidi AT, Roessler J, Coerdt W. Development of the human male urethra: A histochemical study on human embryos. J Pediatr Surg. 2014;49(7):1146–52. Jacob, Monika, Faisal Yusuf, and Heinz Jürgen Jacob. Development, differentiation and derivatives of the Wolffian and Müllerian Ducts. INTECH Open Access Publisher, 2012. Sajjad Y. Development of the genital ducts and external genitalia in the early human embryo. J Obstet Gynaecol Res. 2010;36(5):929–37.

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Question 12 Fig. 7.13 Clinical photograph of a male fetus with an anorectal malformation with recto-vesical fistula

12.1 What is meant by the term “cloaca”? 12.2 The cloacal membrane can be conceptualised as two triangles anteriorly and posteriorly, based on their ultimate anatomical appearance. Name these two triangles. 12.3 Deficiency in the dorsal component of the cloacal membrane and the adjacent dorsal cloaca leads to what abnormality? 12.4 Why can you get a recto-vesical fistula in boys but not in girls? Further Reading Chapter 4: The embryology of anorectal malformations. In: Holschneider AM, Hutson JM, editors. Anorectal malformations in children: embryology, diagnosis, surgical treatment, follow-up. Springer Science & Business Media; 2006. Paidas CN, Morreale RF, Holoski KM, Lund RE, Hutchins GM. Septation and differentiation of the embryonic human cloaca. J Pediatr Surg. 1999;34(5):877–84.

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Part Two: Answers Question 1 1.1 The first 8 weeks is the embryonic period during which time most organs have differentiated. The subsequent 8–40 weeks is the fetal period (changes are essentially those of maturation of each organ system). 1.2 A – the notochord, B – the neural groove, C – the neural crest. 1.3 Neurulation is the process of forming the neural tube from the neural plate. 1.4 The notochord induces the overlying ectoderm to form the neural plate in the third week of gestation. Closure of the cranial neuropore occurs after 25 days and the posterior neuropore after 28 days. 1.5 Neural crest cells are a temporary multi-potent group of cells derived from the embryonic ectoderm. They give rise to: Craniofacial cartilage and bone, Schwann cells, cranial ganglia and nerve sensory cells, melanocytes, enteric ganglia, smooth muscle, adrenal medullary cells, sympathetic and dorsal root ganglia cells. 1.6 Neural crest cell-related diseases (neurocristopathies) include: craniofacial malformations (including cleft lip and palate), tumours affecting the peripheral nervous system (neuroblastoma, schwannoma) and cardiac defects typically affecting the outflow tract. Specific pathologies such as Hirschsprung disease and Waardenburg syndrome are also attributable to neural crest defects. Question 2 2.1 1 – Eustachian (pharyngotympanic) tube, tympanic (middle ear) cavity, 2 – palatine tonsil, tonsillar fossa, 3 – inferior parathyroid gland, thymus, 4 – superior parathyroid gland, ultimobranchial body giving parafollicular C cells. 2.2 The thyroid gland arises as an outpouching from the primitive pharyngeal floor, descending from the foramen caecum. Descent occurs through the fourth to eighth week of development. The developing thyroid gland descends with a variable relation to the hyoid bone, while maintaining a tubular connection with the base of the tongue (the thyroglossal duct). A pyramidal lobe can persist as a midline extension of the gland. 2.3 The superior parathyroid glands are derived from the fourth pharyngeal pouches and are typically found on the posterior surface of the lateral lobe of the thyroid gland. The inferior parathyroid glands are derived from the third pharyngeal pouches and descend with the thymus (also a third pharyngeal pouch derivative) to a variable position in the anterior mediastinum or low in the neck. 2.4 Second pharyngeal cleft anomalies are the most common (accounting for 95%) followed by first pharyngeal cleft. Third and fourth cleft anomalies are rare. 2.5 The tract courses between the internal and external carotid arteries, ultimately terminating in the tonsillar fossa. The external opening lies at the anterior border of the sternocleidomastoid, between the upper two-thirds and lower one-third.

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Question 3 3.1 Bochdalek (Professor of Anatomy, Prague) – posterolateral defect that accounts for the majority of all diaphragmatic hernia cases. Morgagni (Italian Anatomist and Pathologist) – a less common anterior congenital defect causing retrosternal herniation of intra-abdominal contents, usually limited to bowel. 3.2 The septum transversum is a mesodermal plate that forms at week five, originating at the cranial end of the fetus opposite cervical spinal segments 3–5. The septum transversum eventually forms the central tendon of the diaphragm. 3.3 Muscularised precursors (myoblasts) migrate with the phrenic axons derived from cervical myotomes 3–5, initially migrating to populate the pleuroperitoneal folds and then come to cover the rest of the muscular diaphragm. Question 4 4.1 The notochord. 4.2 Apoptosis and differential cellular growth rates. 4.3 Primarily, Shh (“sonic hedgehog” gene), Gli transcription factors (intracellular mediators of Shh signaling) and their downstream genes. 4.4 A cervical rib is due to elongation of the costal element of C7 vertebrae. It is composed of either bony elements or fibrous tissue, passing from C7 vertebra to the first rib. 4.5 Embryonic, pseudoglandular, canalicular, saccular and alveolar. 4.6 Highly significant maturation and development occurs during the third trimester and early postnatal life. It is now recognized that over 85% of alveoli are formed after birth. Further maturation and remodelling occurs, and most of this process is complete by 2 years of age (but can be ongoing up to 8 years of age). The final phase of alveolar formations, which sees the growth of all lung components, continues until around the time the long bones cease to grow. Question 5 5.1 A – right atrium, B – inferior vena cava, C – ductus venosus. 5.2 Foramen ovale. Ductus arteriosus. 5.3 Left pulmonary artery and concavity of arch of aorta (distal to left subclavian). 5.4 Left recurrent laryngeal nerve. 5.5 The aorta and pulmonary trunk. Question 6 6.1 Weeks five and six. 6.2 Around weeks 10–12. 6.3 270° anticlockwise. 6.4 Umbilical cord hernia or exomphalos/omphalocele. 6.5 Exomphalos/omphalocele, anterior diaphragmatic hernia, sternal cleft, ectopia cordis, intracardiac defect (VSD or left ventricular diverticulum)

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Question 7 7.1 A – spleen, B –pancreas. 7.2 Dorsal mesogastrium. 7.3 At 4–5 weeks an endodermal ventral and dorsal pancreatic bud develop (the ventral bud is derived from the biliary diverticulum). After 5–6 weeks in-utero the ventral bud swings posteriorly and the main pancreatic duct starts to connect to it. The ventral pancreatic bud eventually gives rise to the head of pancreas, uncinate process, and the proximal part of the main pancreatic duct. The dorsal pancreatic bud gives rise to the neck, body and tail of the pancreas as well as the minor duct and papilla. Question 8 8.1 The allantois, two umbilical arteries, one umbilical vein, continuation with the extra-embryonic coelom, vitelline duct and associated vitelline vessels. 8.2 Patent urachus if urine. Vitellointestinal fistula if gaseous or feculent. 8.3 A – Meckel diverticulum with a fibrous vitelline ligament connecting to the deep surface of the umbilicus, B – Vitelline cyst attached to both umbilicus and ileum by vitelline ligaments, C – Vitellointestinal/omphalomesenteric fistula/ tract, connecting the ileal lumen to the umbilicus. 8.4 Superiorly: Falciform ligament – ligament teres in free edge. Inferiorly: Median umbilical ligament – obliterated urachus (remnant of allantois). Medial umbilical ligament – obliterated umbilical artery. Lateral umbilical ligament (although not technically emanating from umbilicus) – inferior epigastric artery. Question 9 9.1 Paraxial mesoderm – nearest the midline – develops segmentally into somites that produce: –– sclerotome (surrounds the neural tube and notochord, producing the vertebrae and dura mater) –– myotome (produces the muscles of the body wall) –– dermatome (produces dermis and subcutaneous tissue below ectoderm) • Intermediate mesoderm or intermediate cell mass – progenitor of the urinary and genital systems • Lateral plate mesoderm – unsegmented – splits laterally – critical in developing body wall and separating the body cavities 9.2 • Pronephros • Mesonephros • Metanephros (appears 5th week, gives definitive kidney, invaded by ureteric bud)

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These three develop sequentially from the intermediate cell mass in a cranio-caudal arrangement. 9.3 The ureteric bud forms as an outgrowth of the mesonephric duct through reciprocal induction by the metanephric blastema. The ureteric bud produces not only the ureter; but the renal pelvis, collecting ducts and calices. Caudally the mesonephric duct and ureteric bud are incorporated into the cloaca to form the trigone of the bladder and intramural portion of the ureter. 9.4 The “Weigert-Meyer” rule states the relationship of the ureters in a duplex system, such that upper pole renal moiety ureter inserts into the bladder inferior and medial to the orthotopic lower pole renal moiety ureter. Question 10 10.1 A – left ureter, B – left testis with epididymis and vas deferens. 10.2 The indeterminate gonad originating from the urogenital ridge of the intermediate mesoderm. 10.3 Sexual differentiation of the indeterminate gonad commences at the seventh week under the control of the SRY (sex-determining region Y) gene on the Y chromosome. 10.4 Transabdominal and inguinoscrotal. 10.5 Transabdominal: 8–15 weeks. Inguinoscrotal: 25–35 weeks. 10.6 The round ligament. 10.7 Skin – scrotal subcutaneous tissue has no fat. Dartos – smooth muscle supplied by sympathetic fibres. Colles fascia – continuous with Scarpa’s fascia. External spermatic fascia – contiguous with external oblique aponeurosis. Cremaster – contiguous with internal oblique muscle. Internal spermatic fascia – contiguous with transversalis fascia. Tunica vaginalis – contiguous with the parietal peritoneum (in the presence of a patent processus vaginalis). Question 11 11.1 In females: Uterine tubes, uterus, cervix and the upper one-third of vagina. In males: Appendix testis (cranial end) and classically the fused caudal ends are said to develop into the prostatic utricle (although this has been disputed recently). 11.2 In both sexes will form the trigone of the bladder. In males it also forms the rete testis, epididymis, vas deferens, ejaculatory ducts and seminal vesicles. 11.3 The pelvic part of the urogenital sinus. 11.4 Hypospadias.

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Question 12 12.1 In human embryology “cloaca” is used to denote a transitional organ system of the caudal embryo in which the urinary, genital and hindgut all open into the one cavity or share a common channel. It also is used to describe a congenital anomaly (a severe form of anorectal malformation in which the bowel opens into a urogenital sinus) and it is a normal organ in birds. 12.2 An anterior urogenital sinus and a posterior anorectal triangle. 12.3 Anorectal malformation. 12.4 “High” anorectal malformations with a fistula result in a rectoprostatic or rectovesical fistula in boys, but a rectovestibular or rectocloacal fistula in girls because of the location of the female genital tract interposed between the hindgut posteriorly and urinary tract anteriorly.