CRISP Physiology Complete Review of Integrated Systems Physiology [4 ed.]

Table of contents :
Cover
from publisher's Desk
preface
Acknowledgement
References
Contents
1. General Physiology
your notes
2. cellular Physiology
your notes
3. Physiology of Nerve Fibers
your notes
4. Physiology of Muscles
your notes
5. Neurophysiology
your notes
6. Cardiovascular Physiology
your notes
7. Respiratory Physiology
your notes
8. Exercise Physiology
your notes
9. Endocrine Physiology
your notes
10. Reproductive Physiology
your notes
11. Renal Physiology
your notes
12. Gastrointestinal Physiology
your notes
13. High Altitude, Deep Sea and Space Physiology
!4. Last Minute Revision One Liners

Citation preview

2020 Edition with All New Updates/Qs Covered up to Jan 2020 Most Comprehensive fully-Colored Book on Physiology with Clinical Correlations in Pharmacology, Pathology & Medicine; Only Book Covering Analysis of ECGs & Acid-Base Disorders This Book is Compiled by Leading Faculty & Subject Expert of Physiology

New SARP Series for NEET/NBE/AI

Complete Review of Integrated Systems

Physiology Covering 1500 Qs with Explanations, 100+ IBQs & 500+ Colored Illustrations

References and Updates from Ganong 25/e, Guyton 13/e, Harrison 20/e, Katzung 13/e

New SARP Series for NEET/NBE/AJ

Covering 1500 Qs with Explanations, 100+ IBQs & 500+ Colored Illustrations References and Updates from Ganong 25/e, Guyton 13/e, Harrison 20/e, Katzung 13/e

4th Edition

SKrishna Kumar Mo

THIS BOOK HAS BEEN ATTACHED TO DR. SMET OF TUFTS UNIVERSITY SCHOOL OF DENTAL MEDICINE. TERMS AND CONDITIONS APPLY

~

CBS

CBS Publishers & Distributors

Pvt Ltd

• New Delhi • Bengaluru • Chennai • Kochi • Kolkata • Mumbai • Hyderabad • Nagpur • Patna • Pune • Vijayawada

Dear Readers, I extend my warm welcome and convey my heartfelt thanks for appreciating the CBS Exam Books for another successful year. It has been an amazing journey so far and I am highly grateful for your support and cooperation to help us achieve various milestones in this whole span of time. The mission with which we started in the year 2015 was to bring nothing but the best of everything to our target audience and today I can proudly say that we have maintained that standard and are committed to continue the same in future as well. Every single title under the banner of CBS Exam Books has been developed and nurtured like an infant. The authors and our entire team work day and night to bring the best in everything for you. Be it content, presentation, social media contests and offers, we strive to meet your expectations with every passing year. Your trust has motivated us to maintain and upgrade ourselves during this period. I am extremely thankful to all our authors who are the real pillars of the complete series of CBS Exam Books. The contributions of our esteemed authors have laid the foundations of CBS Exam Books. At this juncture, I can recall these lines by Drake, "Sometimes it's the journey that teaches you a lot about your destination". We have grown and changed with the passage of time to upgrade our ways of providing our readers with maximum benefits and help them manage their time and efforts in effective manner. Previous year was the year of great achievements. Let me show you a glimpse of our successful journey: • Most of the titles of CBS Exam Books received wide acceptance and recognition by the readers of proving their usefulness and supremacy. To mention a few, SARP Anatomy, CRISP, Surgery Sixer, Complete Review of Pathology, Conceptual Review of Pharmacology, SOCH, Forensic Medicine, Complete Review of Medicine, Conceptual Review of PSM, MICRONS, My PGMEE Notes, AIIMS MedEasy, and PRIMEs. With your constant support and our consistent efforts, I am sure that we will together witness an exponential acceptance of all CBS Exam Books in coming future as well. The presence of CBS Exam Books has broadened through our various social media platforms. We have received great appreciation for our regular Facebook activities such as online test series, giveaways, scientific content for knowledge enhancement, authors' live sessions, and various contests, like Bid 2 Win, Fastest Finger First, Book Fair and Facebook Community Awards. Join us on all these platforms to avail and enjoy our exciting offers and benefits. A book is incomplete if it does not have the right readers. We value you and your feedback. Please share your feedback and suggestions directly with me at [email protected]. We promise to deliver in our books, what yo u desire to see. I would like to sum up with these eternal lines of Robert Frost: Woods are lovely dark and deep, But I have promises to keep. And miles to go before I sleep, And miles to go before I sleep! Wishing you success in all your endeavors!

Bhupesh Arora Vice President - Publishing & Marketing (PGMEE and Nursing Division) Email: [email protected] Mobile: (+91) 9555590180

Dear Students,

Gone are those days when you used to get repeated topics and your PG seat was secured. Now the time has changed in such a way that one needs to be thoroughly updated in all the topics as well as it is necessary to interrelate and integrate the information with other medical subjects to keep your preparation at par. Keeping in mind the need of the students and the necessary changes that are required in the present scenario, I have written this book covering all the major aspects of physiology and integrated that information with other medical subjects. Cardinal concepts of physiology are explained in simple and easy-to-understand language. At the end of every physiology topic, clinical information regarding the topic is highlighted in separate boxes so that in short term one can use the information to solve PGMEE MCQs and in long term, it helps in understanding the disease process and to effectively treat various diseases. Information repeatedly asked in PGMEE is given in High Yield boxes. For easy memorization, Mnemonics are given with the complex concepts. At the end of the book, the important topics that have been repeatedly asked in the PGMEE exams have been given separately in point-wise manner for the last-minute revision. Thorough reading of the book helps the students understand all the other relevant information in other PGMEE subjects. Finally I wish, "This book would be the first book that all PG aspirants must read during their PG preparation and this book would be the last choice to revise before they appear for PGMEE:' Grasp the CRISP dear PG aspirants. Happy reading! S Krishna Kumar Email: [email protected]

I sincerely thank all my dear students for the support. Special thanks to: O My wife Dr G Anushuya, my son Rudradheeran and all my family members o Dr R Shivakumar, MD, PhD, -Chairman, CMCHRC (SRM), Trichy, Tamil Nadu O Dr R Rajamahendran MS, MCh (SGE) O Dr T Antan Uresh Kumar MS, MCh (Urology) O Dr D Arun Kumar MD (Pharmacology) 0 Dr Nachal Annamalai, Professor and HOD, Department of Physiology, CMCHRC (SRM), Tamil Nadu O All the members of Department of Physiology, CMCHRC (SRM), Trichy, Tamil Nadu O O

o

All the members of Department of Physiology, AIIMS, New Delhi All the members ofIRT PMCH, Perundurai, Tamil Nadu CMCHRC (SRM) students.

I would like to thank Mr Satish Kumar Jain (Chairman) and Mr Varun Jain (Managing Director), Mis CBS Publishers and Distributors Pvt Ltd for providing me the platform for bringing out the book. I have no words to describe the role, efforts, inputs and initiatives undertaken by Mr Bhupesh Arora (Vice President - Publishing & Marketing, PGMEE and Nursing Division) for helping and motivating me. I sincerely thank the entire CBS team for bringing out the book with utmost care and attractive presentation. I thank Dr Mrinalini Bakshi (Editorial Head & Content Strategist) for her editorial support and Ms Nitasha Arora (Production Head & Content Strategist), Dr Anju Dhir (Project Manager & Senior Scientific Coordinator), Mr Shivendu Bhushan Pandey (Senior Editor), Mr Ashutosh Pathak (Senior Proof Reader) and all the production team members, Mr Chaman Lal, Mr Prakash Gaur, Mr Phool Kumar, Mr Bunty Kashyap, Mr Chander Mani, Ms Tahira Parveen, Ms Babita Verma, Ms Manorama Gupta, Mr Raju Sharma, Mr Manoj Chaudhary, Mr Vikram Chaudhary, Mr Manoj Malakar and Mr Rahul Negi for devoting laborious hours in designing and typesetting of the book.

REFERENCES • Barrett, Kim E., Susan M. Barman, Scott Boitano. Ganong's Review of Medical Physiology, 25/e • Hall, John E. Guyton and Hall Textbook of Medical Physiology, 13/e • Walter F. Boron, Emile L. Boulpaep Medical Physiology, 2/e Updated • Bruce M. Koeppen, Bruce A. Stanton Berne and Levy Physiology, 6/e • lndu Khurana, Medical Physiology for Undergraduate Students, 1/e • Guyton and Hall Physiology Review, 3/e • Linda S. Costanzo, Physiology, 5/e • Stephen J. McPhee, Pathophysiology of Disease: An Introduction to Clinical Medicine, 5/e • Shane Bullock, Majella Hales, Principles of Pathophysiology • Rodney Rhoades, David R. Bell, Medical Physiology: Principles for Clinical Medicine • Dennis L. Kasper, Anthony S. Fauci, Stephen Hauser, Dan Longo, J. Larry Jameson, Joseph Loscalzo. Harrison's Principles of Internal Medicine 19/e • Sabiston Textbook of Surgery, 19/e • Achilles J. Pappa no, Withrow Gil Wier. Cardiovascular Physiology, 10/e • Richard Klabunde. Cardiovascular Physiology Concepts, 2/e • Gerald Karp. Cell and Molecular Biology Concepts and Experiments, 6/e • Susan P. Porterfield. Endocrine and Reproductive Physiology, 4/e • Leonard R. Johnson. Gastrointestinal Physiology, 8/e • Yamada's Textbook of Gastroenterology, 6/e • Wintrobes Clinical Hematology, 13/e • Robbins and Cotran Pathologic Basis of Disease, 9/e • Bertram G. Katzung, Susan B. Masters, Anthony J. Trevor. Basic and Clinical Pharmacology 12/e • Eric Kandel. Principles of Neural Science, 5/e • Duane E. Haines. Fundamental Neuroscience for Basic and Clinical Applications, 4/e • Larry Squire, Floyd E. Bloom, Nicholas C. Fundamental Neuroscience, 3/e • Dale Purves. Neuroscience 5/e • Kaplan. USM LE Step 1 Lecture Notes 2017 : Physiology • Patricia Metting. Physiology Pre Test Self-Assessment and Review 14/e • Costanzo, Linda S. Board Review Series Physiology, 5/e • Bruce M. Koeppen, Bruce A. Stanton. Renal Physiology, 5/e • John Burnard West. Respiratory Physiology: The Essentials, 9/e • Michael G. Levitzky. Pulmonary Physiology, 7/e • Pearce Wilcox. Pulmonary Function Tests in Clinical Practice • Park's Textbook of Preventive and Social Medicine, 23/e

Preface Acknowledgements Recent Pattern Questions 2020 At a Glance

1.

2.

GENERAL PHYSIOLOGY ................................................................................................................ 1- 19

12

Answers of Image-Based Questions

13

Multiple Choice Questions Answers with Explanations

14 16

CELLULAR PHYSIOLOGY ............................................................................................................ 21-44

Answers of Image-Based Questions Multiple Choice Questions Answers with Explanations

5•

Theory

46

Image-Based Questions Answers of Image-Based Questions

51 51 52 54

PHYSIOLOGY OF MUSCLES ........................................................................................................ 57- 74 Theory Image-Based Questions Answers of Image-Based Questions

58

Multiple Choice Questions

69

Answers with Explanations

71

66 68

NEUROPHYSIOLOGY ................................................................................................................. 75-152 Theory Image-Based Questions Answers of Image-Based Questions Multiple Choice Questions Answers with Explanations

6.

22 36 36 37 40

PHYSIOLOGY OF NERVE FIBERS ................................................................................................ 45-56

Multiple Choice Questions Answers with Explanations

4.

2

Theory Image-Based Questions

Theory Image-Based Questions

3.

xiii

76 127 128 130 139

CARDIOVASCULAR PHYSIOLOGY ......................................................................................... 153-220 Theory Image-Based Questions Answers of Image-Based Questions Multiple Choice Questions Answers with Explanations

154 195 198 200 208

7.

RESPIRATORY PHYSIOLOGY .................................................................................................. 221-281 Theory Image-Based Questions Answers of Image-Based Questions

(/)

Multiple Choice Questions Answers with Explanations

f-

zw fz 0 u

8.

Multiple Choice Questions Answers with Explanations

Image-Based Questions Answers of Image-Based Questions Multiple Choice Questions Answers with Explanations

Image-Based Questions Answers of Image-Based Questions Multiple Choice Questions Answers with Explanations

Image-Based Questions Answers of Image-Based Questions Multiple Choice Questions Answers with Explanations

Image-Based Questions Answers of Image-Based Questions Multiple Choice Questions Answers with Explanations

428 443 445 446 451

HIGH ALTITUDE, DEEP SEA AND SPACE PHYSIOLOGY .......................................................457-461 Theory Multiple Choice Questions Answers with Explanations

14.

390 415 416 417 421

GASTROINTESTINAL PHYSIOLOGY .......................................................................................427-456 Theory

13.

362 380 380 381 384

RENAL PHYSIOLOGY ....................................................................................................•..........389-426 Theory

12.

290 347 347 348 353

REPRODUCTIVE PHYSIOLOGY ............................................................................................... 361-387 Theory

11.

284 287 288

ENDOCRINE PHYSIOLOGY .....................................................................................................289-359 Theory

10.

271

EXERCISE PHYSIOLOGY ..........................................................................................................283-288 Theory

9.

222 260 263 265

458 460 461

LAST MINUTE REVISION ONE LINERS (CHAPTERWISE) ...................................................... .463-472

-

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Imagine what happens to our blood glucose levels after food intake? It rises but not indefinitely. It is immediately sensed by beta cells of pancreas and insulin is released, which brings back blood glucose to near normal levels. The concept here is CONSTANCY. All our body parameters have to be maintained at NEAR NORMAL levels. This concept of CONSTANCY is called HOMEOSTASIS. The term was coined long ago by WALTER CANNON. Now what maintains it? Well yes, we have control systems.

REMEMBER KIDNEY displays infinite feedback gain principle in regulation of BP, which means it won't leave any error during correction of BP. It brings BP back to the exact previous value.

Positive Feedback

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0 0 0 >_J

Volume

Indicators

Total Body .. Water

Deuterium (most commonly used}, Tritium, Antipyrine

Extracellular fluid

lnulin (gold standard substance), Sucrose, Mannitol, Sodium Thiosulphate

Plasma l(Olume

Evans blue dye,

Blood volume

51

Interstitial fluid

Calculated as extracellular fluid volume plasma volume

Intracellular fluid

Calculated as total body water - extracellular fluid volume

125

...ra

2

100

Qi u

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!:;

50

1-albumin

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Anions

Cations

~ 0++~-+-,-:-+--,--.,.-;1--H-~-t--l!!---1-a:-+-~+t-~

Cr-labeled red blood cells, or calculated as blood volume= plasma volume/(1- hematocrit)

E

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}>~~"'""\\\.'\:>~\ ~~~'\.~~ "\:>~\""\\\c,. \\c,.~ le,.~\.}>~(. '-1'.'\.'\.\~'\. protein, it is called fac ilitated di ffusion.

•

Another example for th e substan ce that use fac ilitated diffusion carrier protein is WATER transport using AQUAPO RINS \~QI?\.

•

In 2003, Nobel prize in Chemistry was awarded to Peter Agre for the discovery of aquaporins.

Jim17le OiJFu-.slo« •

The best example fo r simple diffusion process is diffusion of gases at resp iratory memb rane in lung a\veoh.

•

If there is any problem in this di ffus ion process at lung alveoli, it can be investigated usi ng a technique called

Aquaporin Members

Location

AO.PO

Lens

• •

•

Here, the simple diffusio n process is fac ilitated by a carrier protein. Glucose transport occurs via carrier proteins called Glucose Tran sporters (GLUT). Hence it is an example of facilitated diffusion. Glucose transporters are characterized by the presence of 12 Transmembra ne Domains.

A\

Clinical importance

GLUT Members

Location

GLUT 1

Brain, RBC, placenta

GLUT 2

~cells

GLUT 3

Brain

GLUT 4 (Insulin dependent)

Skeletal muscle, heart, adipose ti ss ue

GLUT 5 (transports fructose)

Testis, intestine

GLUT 6

Brain, spleen

GLUT7

Intestine, testis, prostate

GLUT 8 (Insulin dependent)

Blastocyst, brain

GLUT 9

Liver, kidney

of pancreas, liver

Linked to Human Disease GLUT 1 deficiency syndrome Infantile seizures, microcephaly Fanconi Bickel syndrome Hyperglycemia, hyperlipidemia, dwarfi sm

Type 2 Diabetes Mellitus

GLUT 10

Liver, pancreas, heart

GLUT 11

Heart, muscle

GLUT 12 (Insulin dependent)

He a rt, prostate

GLUT 13

Brain

Arterial tortuosity syndrome

0

AQPl

Proximal convoluted tubules in kidney

AQP 2 (Regulated by AntiDiuretic Hormone, ADH)

Ap ical part of collecting tubule in kidney

AQP3

Basolateral part of collecting tubule in kidney

AQP4

Blood brain barrier

AQPS

Salivary glands, cornea

AQP6

Kidney

AQP7

Kidney, te stis

AQP8

Intestines, kidney

AQP9

Liver, leucocytes, brain

AQP 10

Intestine

AQP 11

Kidney, brain

AQP 12

Digestive enzyme secreting acinar cells of pancreas

Clinical im ortance • •

•

Renal hypouricemia

m

AJ

Diffusion Lung Capacity using Carbon monoxide (DLCO).

Facilitated Diffusion

--i

I

Loss of function mutation in AQP-0: Congenital cataract. Loss of function mutation in AQP-2 : Nephrogen ic diabetes mutation (remember this disease is due to a defect in ADH receptor V2 in apical side of collecting tubule) . Autoantibodies against AQP-4 lead to autoimmune demyelinating disease, Neuromyelitis Optica (NMO, Devic's syndrome) . A highly specific autoantibody directed against the water channel protein aquaporin-4 is present in the sera of 6070% of patients, who have a clinical diagnosis of NMO.

HIGH Y IELD POINTS Concept of Saturation Kinetics • Transport processes, which use carrier protein s namely facilitated diffu sion and active transport reaches a plateau called as saturation kinetics because the availability of carrier protein is limited . Such process can't continue indefinitely.

Contd .. .

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Facilitated diffusion

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The difference between the measured serum osmolality and calculated serum osmolality is called osmolar gap. • Solutions that have the same osmolality as plasma are said to be isotonic; those with greater osmolality are hypertonic; and those with lesser osmolality are hypotonic. • The osmotic pressure IT (Pi) of a solution containing n moles of solute particles in a solution of volume V is given by the van't Hoff equation: l1 = nRT IV, in which R is the gas constant and T is the absolute temperature. • Plasma osmolarity is usually calculated by the formula, Osmolarity (mOsm/L) = 2[Na+) (mEq/L) +0.055 [Glucose] (mg/dL) + 0.36 [BUN] (mg/dL)

cc

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• Transports 2 sodium and 1 iodide into thyroid follicular cell • Thyroid-stimulating hormone (TSH) increases the expression of NIS in thyroid gland • Clinically, NIS is useful in isotopic scanning, treatment of hyperthyroidism, and ablation of thyroid cancer with radioisotopes of iodine • Mutation in NIS gene- leads to congenital hypothyroidism • Sodium Iodide symporter can be blocked by perchlorate and thiocyanate. Both these agents compete with iodide for transport (competitive inhibition) . They are useful in amiodarone-induced hyperthyroidism .

Na• K· 2c1· cotransporter (NKCC)

Thick ascending loop of Henle

• NKCC is the target for loop diuretics namely furosemide, bumetanide, and torsemide • NKCC mutation leads to Bartter's syndrome type 1 characterized by hypokalemia and metabolicalkalosis

Na· c1cotransporter (NCC)

Distal convoluted tubule

• NCC is the target for thiazide diuretics namely hydrochlorothiazide, indapamide, metolazone. • NCC mutation leads to Gitelman's syndrome characterized by hypokalemic alkalosis and hypocalciuria

Sodium phosphate cotransporter

Intestine, proximal convoluted tubule

• Vitamin D increases Na•/Po 2· co-transporter expression in intestine for phosphate absorption • Parathormone increases phosphate excretion in the kidney by blocking Na•/po 2· co-transporter in PCT • Mutation in Na•/po 2·co-transporter gene leads to Hereditary hypophosphatemic rickets with hypercalcemia

Sodium calcium exchanger

Heart

• Transport 3 sodium ions inside and one calcium ion outside the cell • Sodium calcium exchanger functions in opposite direction when intracellular sodium level rises i.e. transport 3 sodium ions outside and one calcium ion inside the cell. lnotropic agent digitalis enhances myocardial contractility by this mechanism by blocking Na• K• pump and increasing intracellular sodium levels

Chloride bicarbonate exchanger

RBC, intercalated cells in kidney

• Also called Band 3 protein or anion exchanger 1 (AEl) • Responsible for the phenomenon of Chloride shift or Hamburger shift

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w

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1000) mutations in the LDL receptor gene.

Light chain

Limitations of BOTOX use: The relaxant effects of the toxin are often temporary and so it needs to be injected once every 2-3 months.

Fig. Clathrin Triskelion

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Other Proteins Involved in Endocytosis

Caveolin

Mega/in

•

• •

Highly abundant in renal proximal convoluted tubules. Responsible for the endocytosis of insulin, albumin, hemoglobin, vitamin D-binding protein .(DBP), retinolbinding protein (RBP).

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m 0

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m (/) --i

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z

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1. Ans. (d) Glucose transport into skeletal muscle

Ref Guyton, 13th ed p.51

Simple diffusion

vmax

c

0 ·u; ~

'6

---------__l+ _~--~--..-:; .,;c

-F -

-~--~-- -~--~--=-- . Facilitated diffusion

Q)

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• Transport processes which use carrier proteins namely facilitated diffusion & active transport reaches a plateau called as saturation kinetics • Glucose transport into skeletal muscle using GLUT transporter is facilitated diffusion which shows saturation kinetics • In contrast, simple diffusion process continues indefinitely

2. Ans. (b) Exocytosis (Ref Ganong, 25th ed p.46) • Exocytosis is a calcium dependent process where in the cellular contents are moved out of the cell in the form of vesicles (Cell Vomiting)

3. Ans. (d) 12 (Ref Ganong, 25th ed/p.684) Concentration of substance

• Na K 2Cl is present in the thick ascending loop of Henle • It has 12 transmembrane domains

Homeostasis and Body Fluids

>0 0 _J 0 (/) >:r: o_ _J

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z

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0

z

(./)

J\i:tes

Cell theory, proposed by Schleiden and Schwann states that: All living organisms are composed of cell or cells. Cells are the functional units of life. All cells arise from pre-existing cells.

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Composition of Cell Membrane Membrane

PARTS OF A CELL

(.'.)

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Vacuole -=:&~~~~::::::Ir::_=_=_=-_~-,-_-_-_ Ribosomes Golgi Cell membrane Cytoplasm apparatus

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Nucleolus -fr---(.'.)

0 0 (/) >_J

-60 to-40 mV

Resting membrane potential once generated, it is maintained by the activity of Na• K+ pump.

•

Equilibrium Potential •

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At a particular membrane potential, an ion cannot move inside the cell and it cannot move outside of the cell too. The membrane potential at which this equilibrium exists is the equilibrium potential.

This effect states that "when an ion on one side of a membrane cannot diffuse through the membrane, the distribution of other ions to which the membrane is permeable is affected in a predictable way". Membrane (m) between compartments X and Y is impermeable to charged proteins (Prat-) but freely permeable to K+ and Cl-. It is the negatively charged protein anions which is nondiffusible and is responsible for negative resting membrane potential when potassium diffuses out.

x

Equilibrium potential for a single ion can be calculated from Nernst equation.

-

Mitochondria

0 0 >-

Outer membrane - Monoamine oxidase Inner membrane - ATP synthase, succinate dehydrogenase

Lysosome

Acid phosphatase

(.'.) _J

Synaptic terminal

(/)

:r: o_

Peroxisomes

Catalase, urate oxidase

Endoplasmic reticulum

GI ucose-6-phosphatase

Golgi apparatus

Galactosyl trasferase, Sialyl transferase

Plasma membrane

5'-Nucleotidase, Na KATPase

Cytoplasm

Lactate dehydrogenase

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w

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Retrograde axonal transport Dynein mediated Fig. Axonal Transport

REMEMBER

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Lipid bilayer

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a. b. c. d.

Cis golgi complex Trans golgi complex Smooth endoplasmic reticulum Medial golgi complex

a. Cholesterol c. Stearic acid

b. Phospholipid d. Palmitic acid

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2. Ans. (c) +80

1. Ans. (a) Depolarisation

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(Ref Guyton & Hall 13th ed. Ch -5, p. 61-63)

(Ref Guyton Textbook of Medical Physiology, 11th ed, p.58)

:r:

• Under equilibrium state X + Y + Z = O... so z must be +70 m V.. .we are blocking this + 70 m V with a drug ... so obviously now the potential will be in between -30 and -40 mV which is a state of depolarisation.

• No net electro genie transfer at RMP means X + Y + Z = 0 • Since X = - 50 and Y = -30, then Z must be +80 since (- 80 + 80 = 0)

0.... Ck:

z)>

-i

0

z

(./)

>-

(.'.)

0

Organelle

Marker enzyme

Endoplasmic reticulum

GI ucose-6-phosphatase

Golgi apparatus

Galactosyl trasferase, Sialyl transferase

Plasma membrane

5' -N ucleotidase, Na K ATPase

Cytoplasm

Lactate dehydrogenase

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24. Ans. (a) Galcotosyl transferase

G'.'.

25. Ans. (c) Glycosidases

:::) _J _J

l.l.J

u 0 N

(Ref Ganong, 25th ed!p.43) • Important enzymes present in lysosomes are acid phosphatase, cathepsins, glucosidase, acid lipase, collagenase 26. Ans. (d) Lysosomes

(Ref Ganong, 25th ed!p.)

o_

• Once the digestive process in the lysosome has been completed, it is termed as residual body • The contents of the residual body may be retained within the cytoplasm as lipofuscin granule • Lipofuscin granule increase in number as we get older (aging)

41. Ans. (b) K+

42. Ans. (b)

I

Connexin{Cx) subtype mutation

39. Ans. (c) Connexons are involved in electrical synapse (Ref Ganong's Review of Medical Physiology, 25th ed., ch-2, p. 41-42)

~ =i

Cell

RMP

Neuron

-70 mV

Skeletal muscle

-90 mV

Cardiac ventricle

-90 mV

z

-i

z

(/)

RMP

Retinal Rods

-40 mV

Inner ear hair cells

- 60 mV

Sino Atria l Node

- 60 to - 40 mV

Na+

+60 mV

Gastroi ntest ina l smooth muscle

- 60 to-40 mV

K+

c-90 mV

c1-

-70 mv

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ACTION POTENTIAL •

-70

Action potentials are the primary electrical responses of neurons and they are the main form of communication within the nervous system. The morphology of nerve action potential is shown below.

Resting potential Time

CL

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REMEMBER

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Oligodendrocyte can myelinate multiple neurons at a time but Schwann cell can myelinate only one neuron at a time. Myelin is present throughout the nerve fibers except at Nodes ofRanvier.

0:::

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Myelin is formed by oligodendrocytes in central nervous system . Myelin is formed by Schwann cells in peripheral nervous system.

•

(/)

m

0

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m

(/)

-i

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(/)

1. Identify the ions based on conductance graph of a neuron

shown below

(PGI May 2018)

2. In this diagram depicting nerve action potential, point at which potassium ion permeability is highest is?

20

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NE

,g.0 30

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c

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0

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Z line

Z line

L.__ Sarcomere ---'---·'-'arcomere--~

)

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Z line

Fig. Structure of Sarcomere

The area between two Z lines is a Sarcomere. I band: Made up of mainly actin filaments. They appear light when viewed under microscope. A band: Made up of mainly Myosin. They appear dark when viewed under microscope.

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I band - actin filaments A band - mainly myosin

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M line: runs exactly through the center of myosin A band . The M line is the site of the reversal of polarity of the myosin molecules. H band: The lighter H bands in the center of the A bands are the regions where, when the muscle is relaxed, the thin filaments do not overlap the thick filaments. When muscle contracts, • Z lines come closer • Length of H and I band decrease • Length of A band remains constant

MUSCLE PROTEINS •

Proteins in muscles perform various functions. They can be contractile proteins, structural proteins, regulatory proteins and relaxation proteins. Contractile Proteins

Structural Proteins

Regulatory Proteins

Relaxation Proteins

They are mainly actin and myosin

Tit in:

These proteins regulate muscle contraction and relaxation

SERCA pump:

Actin filaments:

• They are the thin filaments • Made up of two chains of actin that form a long double helix • Each thin filament contains 300-400 actin molecules

•

It is the largest known protein present in mammals • Also called as "muscle spring" because it is responsible for "Elasticity" in muscle • Connects the Z lines to the M lines and provides scaffolding for the sarcomere

Myosin:

Desmin:

• Thick filaments {1.6µ) • The form of myosin found in muscle is myosin·ll • Has two globular heads and a long tail • Myosin contains heavy chains and light chains • Myosin head contains an actin·binding site and a catalytic site that hydrolyzes adenosine triphosphate (ATP)

• It is the intermediate filament of muscle • It connects Z lines to the plasma membrane Actinin:

• It binds actin to the Z lines Dystrophin-Glycoprotein complex:

• Adds strength to the muscle by providing a scaffolding for the fibrils and connecting them to the exterior • Its components are dystroglycan, merosin, syntrophins and sarcoglycan

Troponins:

• Has three subunits namely, • Troponin C: contains the binding sites for the ca 2• that helps initiate contraction • Troponin I: inhibits the interaction of myosin with actin • Troponin T: Binds the

troponin components to tropomyosin. Tropomyosin molecules are long filaments located in the groove between the two chains in the actin

•

Located in sarcoplasmic reticulum which takes up calcium ions leading to muscle relaxation Calsequestrin: • It is the calcium buffering protein that buffers calcium ions so that no free calcium ions available for muscle contraction

EXCITATION CONTRACTION COUPLING • •

•

Skeletal muscles are voluntary in nature, which means that for contraction they need excitation in the form of action potential. Skeletal muscles are excited by spinal alpha motor neuron. Each single motor neuron and the muscle fibers it innervates constitute a motor unit. A modified form of synapse called neuromuscular junction is formed at the point of contact of spinal alpha motor neuron with skeletal muscle fiber.

•

•

Neuromuscular Junction-The Excitation Part •

• •

•

•

In response to a stimulus, sodium ions enter the axon of motor neuron leading to depolarization. This reduces the membrane potential in motor nerve axon. When the impulse reaches the end of axon, it increases the permeability to calcium ions. Calcium ions enter the axon of motor neuron through voltage gated calcium channels. It' is this calcium entry that causes exocytosis of acetylcholine stored in motor nerve terminals. Acetylcholine, once released into the synaptic cleft is degraded by the enzyme acetylcholine esterase. Few molecules of Ach which escapes degradation finds its receptor, nicotinic acetylcholine receptor in the muscle. Nicotinic acetyl choline receptor in the muscle is NM type. Binding of acetylcholine to these receptors increases influx of Na+ ions leading to a depolarizing potential called the endplate potential. Endplate potential is always a depolarizing potential.

Voltage gated Na· channels Voltage gated Ca 2 • channels

Postsynaptic end (muscle endplate)

•

An average human endplate contains about 15-40 million acetylcholine receptors. Each nerve impulse releases acetylcholine from about 60 synaptic vesicles, and each vesicle contains about 10,000 molecules of Ach. This amount is enough to activate about 10 times the number of NM receptors (safety factor). Even at rest, small quanta of acetylcholine are always released randomly at the synaptic cleft. This leads to a small potential called as miniature endplate potential, which is about 0.5 mV in amplitude. This small amount of Ach release varies directly with the Ca 2+ concentration and inversely with the Mg 2+ concentration at the endplate. The orderly arrangement of neuromuscular junction is maintained by proteins called neurexins.

HIGH YIELD POINTS Even at rest, small quantities of acetylcholine are always released - miniature endplate potential

• Neuromuscular Junction in Pharmacology Skeletal Muscle Relaxants • Neuromuscular transmission blockers are frequently used as muscle relaxants during surgical anesthesia • Two groups of skeletal muscle relaxants are available. • One group blocks the binding of acetylcholine to its receptor thereby preventing depolarization . So, they are called as competitive or non-depolarizing muscle relaxants. The drugs of this group are Tubocurarine, pancuronium, cistracurium, vecuronium, gantacurium, etc. • Another group of drugs acts as agonist to acetylcholine receptor and causes sustained depolarization . Initial depolarization causes transient contractions, followed by prolonged flaccid paralysis. They are called Noncompetitive or depolarizing muscle relaxants. The drug is succinylcholine. Acetylcholine Esterase Inhibitors • By inhibiting acetylcholine esterase, this group of drugs amplifies all actions of acetylcholine. The drugs are edrophonium, physostigmine, neostigmine, echothiophate. Other neuromuscular blockers: #-

Fig. Neuromuscular Junction •

Endplate potentials are local potentials. Once they cross the threshold, action potential is fired. In response to the action potential, muscle contracts.

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Agent

Mecflanlsm ofActfon

Tetrodotoxin (source Puffer fish) Dendrotoxin (source Mamba snake) Conotoxin (source - Snail)

Presynaptic voltage gated sodium channel blocker Presynaptic voltage gated potassium channel blocker Presynaptic voltage gated calcium channel blocker

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Frequency of muscle contraction Muscle mass Hypertrophy Myosin ATPase activity

1. Ans. (a) Alpha actinin C/)

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Titin : • It is the largest known protein present in mammals • Also called as "muscle spring" because it is responsible for "Elasticity" in muscle • connects the Z lines to the M lines and provides scaffolding for the sarcomere

Desmin: • It is the intermediate filament of muscle • It connects Z lines to the plasma membrane

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Dystrophin-Glycoprotein complex: • adds strength to the muscle by providing a scaffolding for the fibrils and connecting them to the exterior • Its components are dystroglycan,merosin, syntrophins and sarcoglycan 2. Ans. (d) 30 - 35 Hz (Ref Ganong, 25th ed!p.107)

• • • • • •

In this question, each block corresponds to 10 mm Paper speed is lOOOmm/sec Contraction period includes 3 blocks. So,its 30 mm 1000 mm = 1 sec. So,30mm = 30/1000 = 30msec So, contraction period = 30 msec Tetanizing fre quency = I/contraction period = 1000/30 = 33 Hz

3. Ans. (b) Point Band C (Ref Guyton and Hall Physiology Review, 3rd ed!p.14)

• In the above picture, maximum tension generated by the muscle is between point B and C. • It corresponds to the sarcomere length of 2.2 micrometers. • It is at this segment BC where there is optimal overlap between actin and myosin. • On either side of BC, tension produced by the muscle decreases 4. An s. (c) a -actinin (Ref Gautel et al. Journal of Experimental Biology (2016) 219, 135-145)

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(Ref Ganong 25th ed p.100) • Once calcium ions are released from sarcoplasmic reticulum, they immediately binds with the troponin subunit troponin C • At rest, myosin binding site in actin is covered by troponin I and troponin Also at rest, the myosin head contains tightly bound adenosine phosphate (ADP) • Binding of calcium with troponin C causes a conformational change by removing troponin I and troponin T and exposed the myosin binding site in actin • Now myosin is free to interact with actin forming cross bridges. • Upon formation of the cross-bridge, ADP is released, causing a conformational change in the myosin head that moves the thin filament relative to the thick filament, comprising the cross-bridge "power stroke''. This sliding of microfilaments is the basis of sliding filament theory of muscle contraction • After a power stroke, ATP binds to the myosin head. Whenever ATP binds to myosin head, it gets detached from actin • Myosin head has ATPase activity which hydrolyses the ATP to ADP and inorganic phosphate. • Now the myosin head with ADP starts the next cycle 4. Ans. (d) Excess catecholamines (Ref Ganong 25'" ed p.113) • Calcium is taken up back and stored in the Sarcoplasmic reticulum through SR Ca 2+ ATPase (SERCA 2J. • It is regulated by phospholamban, which inhibit SERCA pump and it interferes with the storage of calcium. When phospholamban is phosphorylated, it is inhibited. Norepinephrine phosphorylates phospholamban and inhibits it. • By doing this, Norepinephrine enhances SR stores of calcium and enhances relaxation. This action of norepinephrine is called positive lusitropic effect

Z line

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[______ Sarcomere --~--,..,arcomere --~ • The area between two Z lines is a Sarcomere 8. Ans. (b) Tropomyosin (Ref Ganong, 25th ed!p.101) 9. Ans. (c) Myosin (Ref Ganong, 25th ed!p.100) • Actin is the thin filament and myosin is the thick filament IO. Ans. (c) Actin

(Ref Ganong, 25th ed!p.100) • Binding of calcium with troponin C causes a conformational change by removing troponin I and troponin T and exposed the myosin binding site in actin I I. Ans. (c) Terminal cistern (Ref Ganong, 25th ed!p.101) • Sarcotubular system has two tubules namely T tubule and L tubule. • T tubules are present in the sarcolemma (plasma membrane of muscle) and L tubules are the sarcoplasmic reticulum (smooth endoplasmic reticulum of muscle) which stores and release calcium called as terminal cisterns located at the junction of A and I band

12. Ans. (a) SERCA

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(Ref Ganong, 25th ed!p.110)

• Once the contraction process is over, calcium ions are immediately pumped back into the sarcoplasmic reticulum for storage using a pump called sarcoplasmic or endoplasmic reticulum Ca 2 + ATPase (SERCA)

• Active tension in a muscle depends upon the number of motor units recruited

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(Ref Ganong, 25th ed/p.101) • Once the contraction process is over, calcium ions are immediately pumped back into the sarcoplasmic reticulum for storage using a pump called sarcoplasmic or endoplasmic reticulum Ca 2+ ATPase (SERCA) • Once the Ca2+ concentration outside the sarcoplasmic reticulum has been lowered sufficiently, chemical interaction between myosin and actin ceases and the muscle relaxes 14. Ans. (b) Ca binding troponin C

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Produced if the neurotransmitter released at the synapse is excitatory. The excitatory transmitter opens Na+ or Ca 2+ ion channels producing depolarization. EPSPs summate to produce action potential. EPSP in neuromuscular junction is called as end plate potential. High-frequency stimulation of the presynaptic neuron can generate 500 - 1,000 action potentials per second. This phenomenon is called tetanic stimulation. The increase in size of the EPSP during the above said tetanic stimulation is called potentiation. Any further increase that persists after tetanic stimulation is called post-tetanic potentiation.

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Heat nociceptors

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Hot temperature (>45°C)

Cold nociceptors

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Receptor Cool receptors

Nerve Fiber Type

Detects

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Transient Receptor Potential (TRP) Channels • •

These receptors are non-specific ion channels present in nociceptive nerve endings. Subtypes: TRPV channels: V refers to a group of chemicals called • vanilloids. They are activated by intense heat and chemicals like capsaicin. This capsaicin is the active principle of hot peppers- an example of a vanilloid - causes burning type pain.

Slowly Adapting Receptors Neural

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• These type of receptors fire in response to a stimulus initially but if the stimulus is maintained, they stop firing. • Examples are Meissner corpuscles, Pacinian corpuscles.

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Stimulus _ _ r - L

• These type of receptors fire in response to a stimulus initially but if the stimulus is maintained, they continue firing but their frequency is decreased. • Examples are Merkel cells, Ruffini corpuscles, Pain receptors, Muscle spindles, joint capsule receptors.

Primary Afferent Nerve Fibers Innervating Sensory Receptors

Deep and Visceral Pain

For Touch Sensation

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• Thi s type of pain is also called fast pa in or epicritic pa in

• Thi s type of pain is also called slow pain, protopathic pain

• Mainly responsible for localizing the site and intensity of the noxious stimulus

• Always dull, intense, diffuse, and gives unpleasant feeling

• Relatively new in evolutioncarried by neospinothalam ic tract

• Very old in evolution-carried by paleospinothalamic tract

• Relea se glutamate as neurotransmitter

• Release glutamate and substance Pas neurotransmitter

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Administer a single dose of 200,000 IU of vitamin A orally every 6 months to preschool children (1-year to 6 years) .

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Administer half of that dose (100,000 IU) to children between 6 months and one year of age .

Congenital stationary night blindness •

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Conditions Associated with Retinitis Pigmentosa

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Occurs following bilateral strokes involving the ventral portion of the occipital lobe. The area affected is visual area VS . These patients can perceive only shades of gray.

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Red - sensitive, or long-wave or L cone - sensitive to wavelength 560 nm

The theory that postulates the existence of three kinds of cones is called Young-Helmholtz theory of color vision.

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Cones in retina are the receptors for color vision. Three primary colors are blue, green, and red. Correspondingly human retina has three types of cones namely,

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Color anemia

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Occurs due to Infarcts of the dominant occipital lobe . Affected patients can discriminate colors but cannot name them .

(){, Color Vision and Pharmacology Drugs that cause color vision abnormalities:

Neural Mechanisms

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• All auditory pathways ascending through the brain stem converge in inferior colliculi • Helps in localization of sound and the direction from which the sound comes

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Auditory cortex

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Tonic labyrinthine reflexes

Gravity

Contraction of limb extensor muscles

Otolith organs

Medulla

Tonic neck reflexes

Head turned: • To side • Up • Down

Change in pattern of extensor contraction: • Extension of limbs on side to which head is turned • Hind legs flex • Forelegs flex

Neck proprioceptors

Medulla

Labyrinthine righting reflexes

Gravity

Head kept level

Otolith organs

Midbrain

Neck righting reflexes

Stretch of neck muscles

Righting of thorax and shoulders, then pelvis

Muscle spindles

Midbrain

Body on head righting reflexes

Pressure on side of body

Righting of head

Exteroceptors

Midbrain

Body on body righting reflexes

Pressure on side of body

Righting of body even when head held sideways

Exteroceptors

Midbrain

Optical righting reflexes

Visual cues

Righting of head

Eyes

Cerebral cortex

Placing reactions

Various visual, exteroceptive, and proprioceptive cues

Foot placed on supporting surface in position to support body

Various

Cerebral cortex

Hopping reactions

Lateral displacement while standing

Hops, maintaining limbs in position to support body

Muscle spindles

Cerebral cortex

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Fig. Basal ganglia - Frontal section

Lateral ventricle Caudate nucleus Pu tame n Globus palllidus: External segment Internal segment Subthalamic nucelus

Substantia nigra

Subthalamic nucleus

Caudate and Putamen • • •

Collectively called as striatum . They are the major input nuclei of striatum. The neurons seen here are called as medium spiny neurons which stores the neurotransmitter GABA that is inhibitory. Caudate nucleus has got a role in cognition (learning and memory).

Globus Pallidus •

Thalamus Internal capsule

Globus pallidus

Organization of Basal Ganglia

• Now, functions of basal ganglia are better understood by knowing its structural components. They are five in number.

Putament

• •

•

Has two segments: external and internal segments (GPe and GPi) . Is the major output nuclei of basal ganglia. Contains the neurotransmitter GABA which is inhibitory. Tonically active at rest. This is the reason being output of basal ganglia is inhibitory at rest. Pu tam en and glob us pallidus are collectively called as lenticular nucleus.

Substantia Nigra •

The substantia nigra is divided into, • Pars compacta -which uses dopamine as a neurotransmitter. • Pars reticulata - which uses GABA as a neurotransmitter.

Subthalamic Nucleus • •

Also called Luys' body. Contains the excitatory neurotransmitter Glutamate.

Hemiballismus - a violent form of chorea comprised of wild, flinging, large-amplitude movements on one side of the body occurs in lesions of subthalamic nucleus.

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Now, for understanding the function of basal ganglia, the key concept lies in understanding how basal ganglia inhibit all movements at rest. For that, the basis is basal ganglia-thalamic-cortical loop.

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Dopamine receptor agonists: •

Bromocriptine

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Electroencephalography (EEG) • • •

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Is the record of electrical activities of brain. Discovered by Hans Berger, a neuropsychiatrist. Always remember that these electrical activities recorded are not action potentials. They are mainly the graded, slower postsynaptic potentials .. Following waves are seen in human EEG recording, • Alpha wave • Beta wave • Theta wave • Delta wave • Gamma wave.

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Frequency

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14-30 Hz

• Are most prominent over parietofrontal areas • Seen during wakefulness

4-7 Hz

• Generated in hippocampus • Most commonly seen in children • Pathologically seen often in degenerative brain diseases

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• Seen in very deep sleep • If seen in awake individuals - always abnormal. Indicates organ ic brain disease

30-80 Hz

• Seen during focused attention

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• •

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Accompanied by increases in blood pressure, heart rate, and metabolism. Spontaneous penile erection in men. Women experience sexual arousal.

• •

Dreaming •

Dreams occur in both REM and non-REM sleep.

Rapid Eye Movement (REM) Sleep

REM Dream

NREM Dream

•

• Long, primarily visual, emotional

• Shorter, less emotional, more conceptual

• Not connected to the immediate events of the everyday life

• Related to the current life events

•

• •

It is called because of the characteristic eye movement associated with this sleep. Also called as, • Superficial sleep • Active sleep • Paradoxical sleep Called paradoxical sleep because EEG resembles like that of an awake individual. PGO spikes. • Called as pontogeniculo-occipital (PGO) spikes • These large phasic potentials are highly characteristic of REM sleep.

Awake

Sleep and Endocrine Changes • • • • •

Growth hormone level rises in stages 3 and 4 N~M sleep. Prolactin level rises during REM sleep. Around the time of puberty, there is increase in nocturnal LH secretion. Sleep onset is associated with inhibition of thyroid-stimulating hormone(TSH) and ACTH. Pineal hormone melatonin -Secreted predominantly at night. Distribution of sleep stages

REM sleep

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Muscle atonia. • Due to the inhibition of the spinal motor neurons by descending pathways • Muscles that does not undergo atonia during REM sleep are extraocular muscles and diaphragm.

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In adults REM sleep occupies approximately 25% of the total sleep time (Infants - 50%).

NREM sleep occupies approximately 75% of the total sleep time. Stage 2 NREM occupies the maximum duration (45%) followed by stage 3 and 4 (25 %) and least is Stage 1 (5%).

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Learning and Memory

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(Ref Ganong, 25th ed/p.123)

• Microglial cells are the mesoderm derived phagocytic cells of CNS

• Presynaptic facilitation - produced when the action potential is prolonged and the Ca 2+ channels are open for a longer period

15. Ans. (a) Phagocytosis (Ref Ganong, 25th ed!p.85)

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• This law states that "the magnitude of the sensation felt is proportionate to the log of the intensity of the stimulus" • Linear increase is not important. Logarithmic increase is always important to appreciate the magnitude of sensation

Vision 78. Ans. (d) Photoreceptors (Ref Ganong 25th ed p.178)

• Photoreceptors are first order neurons • Bipolar cell is second order neuron • Ganglion cell is third order neuron 79. Ans. (a) 3 - 5 millions (Ref Ganong, 25th ed/p.178)

70. Ans. (b) Pain and temperature

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(Ref Ganong, 25th ed/p.169)

• Lateral spinothalamic tract carries pain and temperature • Anterior spinothalamic tract carries tickle, itch, crude touch and pressure

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75. Ans. (d) Head (Ref Ganong, 25th ed/p.168)

• Dorsal column pathway is the principal pathways for touch, vibration and proprioception. They primarily contain Aa and A~ afferents • They ascend ipsilaterally (same side) in dorsal column of spinal cord to medulla • In medulla, they synapses with two important nuclei namely gracilis and cuneate nuclei. They cross the midline and ascend in the medial lemniscus to end in the contralateral ventral posterior lateral (VPL) nucleus

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• There are 6 million cones in each human eye • There are 120 million rods in each human eye

Rods • They are the receptors of dim vision or night vision • Predominate in extrafoveal regions • More sensitive to light • The photosensitive pigment in the rods is called rhodopsin (visual purple) • On activation, produces hyperpolarizing potential changes

I Cones • They are the receptors of day vision • Predominate in foveal regions • Less sensitive to light • Cone pigments- iodopsin • On activation, produces hyperpolarizing potential changes

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(Ref Ganong, 25th ed!p.222) (Ref Snell's clinical neuroanatomy 7th Ed; Pg. 337)

82. Ans. (c)

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• Tip of the tongue - sweet( more sensitive) • Posterior part of tongue - bitter • Sides of tongue - salt and sour taste 91. Ans. (d) Filiform papillae have taste buds at tip

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(Ref Ganong, 25th ed!p.222)

81. Ans. (d) Bipolar cells

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84. Ans. (d) Hyperpolarization (Ref Ganong, 25th ed!p.179)

• "Vision is the only sense wherein activation of receptors leads to hyperpolarization (EYEperpolarisation)" 85. Ans. (d) Vision

• Taste buds are present in papillae of the tongue • Fungiform, circumvallate, foliate papillae have taste buds • Filiform papillae doesn't have any taste buds 92. Ans. (b) Glutamic acid (Ref Ganong, 25th ed/p.222)

• "Umami is the recently added fifth taste sensation produced by monosodium glutamate (MSG)" 93. Ans. (b) Olfactory bulb (Ref Ganong, 25th ed!p.217)

• Olfactory bulb has got special synaptic units called olfactory glomeruli where four types of cells are seen namely, • Mitral cells • Tufted cells • Granule cells • Periglomerular cells

Reflexes

(Ref Ganong, 25th ed!p.178)

• The G protein coupled receptor in rods is called "Transducin" • Role of transducin is to activate the enzyme phosphodiesterase that degrades cGMP

94. Ans. (b) Tension of the muscle (Ref Ganong, 25th ed/p.232)

86. Ans. (a) Acetylcholine (Ref Ganong, 25th ed!p.179)

• Transmitter substances secreted by amacrine cells are mainly inhibitory. They are, • Gamma-amino butyric acid (GABA) • Glycine • Dopamine, • Acetylcholine • Indolamine 87. Ans. (c) Adrenaline (Ref Ganong, 25th ed!p.179)

• Neurotransmitter stored rods and cones terminal endings is glutamate 88. Ans. (a) 370 - 740 nm (Ref Ganong, 25th ed!p.190)

95. Ans. (a) Upper limb flexed, lower limb extended (Ref Ganong, 25th ed!p.208)

In • • • • •

decerebrate rigidity, Lower extremities are extended Toes pointed inward Upper extremity is extended Fingers flexed and the forearms pronated Neck and head are extended

96. Ans. (b) Tension (Ref Ganong 25th ed p. 232)

• Muscle spindle detects muscle length changes • Golgi tendon organ detects tension changes in muscle 97. Ans. (c) Muscle spindle (Ref Ganong, 25th ed!p.229)

Smell and Taste 89. Ans. (b) Na• channels (Ref Ganong, 25th ed!p.221)

• stretch sensing receptor in muscle is Muscle spindles • Muscle tone - is the resistance offered by the muscle to passive stretch • Muscle tone is maintained because of muscle spindle

98. Ans. (a, b, d) (a) Group Ia fiber contain sensory afferent; (b) Nuclear bag and nuclear chain fibers present in intrafusal muscle fib er ; (d ) Motor supply by y fiber

105. Ans. (b) Length (Ref Ganong, 25th ed/p.231)

(Ref Ganong, 25th ed/p.229) • Sensory innervation of muscle spindles is Group Ia fiber • Nuclear bag and nuclear chain fibers present in intrafusal muscle fiber • Motor supply to spindles is by y fiber • Secondary ending - mainly to nuclear chain fibers

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106. Ans. (a) Change in muscle length

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99. Ans. (b) Bell-Magendie Law

107. Ans. (a) Passive stretch

(Ref Ganong, 25th ed/p.229)

(Ref Ganong, 25th ed/p231.)

• Bell-Magendie law: • This law states that "Spinal dorsal roots contain sensory fibers and ventral roots contain motor fibers"

• During knee jerk testing, we are passively stretching the quadriceps muscle by tapping on its tendon with a knee hammer

100. Ans. (c) Plate endings

108. Ans. (c) Au

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(Ref Ganong, 25th ed/p.231)

• Muscle spindles have their efferent innervation on their own by gamma motor neuron from spinal cord • Gamma motor neurons innervate the peripheral contractile portion of muscle spindles • Gamma motor innervation to muscle spindles can be, • Dynamic gamma motor neurons (plate endings) which innervates the dynamic bag fibers • Static gamma motor neurons (trail endings) which innervates the static bag fibers and the chain fibers

• Alpha motor neurons innervate the actin and myosin which are the extrafusal fibers

101. Ans. (c) y -neuron

109. Ans. (c) Both are activated together

(Ref Ganong, 25th ed/p.232) • For initiating voluntary motor movement, descending excitatory input to spinal motor circuits activates both aand y-motor neurons together • This concept is called "a-y coactivation;' wherein intrafusal and extrafusal fibers shorten together for better function of muscle spindles

(Ref Ganong, 25th ed/p.230) llO. Ans. (a) Dynamic intrafusal fibers

102. Ans. (a) Ia (Ref Ganong, 25th ed/p.229) • The question is about the afferent innervation of muscle spindles • There are two kinds of sensory endings in each spindle primary (group Ia) ending which is single and secondary (group II) endings which is up to 8 103. Ans. (a) Sense dynamic length of muscle

(Ref Ganong, 25th ed/p.232) • Dynamic nuclear bag fibers detect the velocity (rate) of the change in muscle length during a stretch (phasic activity) • Static fibers - detect the steady state length of the muscle (tonic activity) • Stretching the muscle with a knee hammer mainly activates Dynamic nuclear bag fibers lll. Ans. (b) Tendon

(Ref Ganong, 25th ed/p.230)

(Ref Ganong, 25th ed/p.232)

• There are two subtypes of nuclear bag fibers - dynamic and static • Dynamic fibers - detect the velocity (rate) of the change in muscle length during a stretch (phasic activity) • Static fibers - detect the steady state length of the muscle (tonic activity) • The distinguishing feature of nuclear bag fibers is its dynamic fibers. So, the answer is it "Sense dynamic length of muscle"

• Golgi tendon organ are the netlike collection of knobby nerve endings present in tendons

104. Ans. (d) Length and velocity (Ref Ganong, 25th ed/p.231)

ll2. Ans. (d) Golgi tendon organ

(Ref Ganong, 25th ed!p.232) • Receptor for stretch reflex is muscle spindles • Receptor for inverse stretch reflex is Golgi tendon organ 113. Ans. (a) 1 - 20

(Ref Ganong, 25th ed!p232.)

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• Primary motor cortex Is located in the precentral gyrus of the frontal lobe (Brodmann's area 4 ) • Premotor cortex and supplementary motor cortex Brodmann's area 6 123. Ans. (d) Voluntary movement

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162. Ans. (b) Disdiadochokinesia (Ref Ganong, 25th ed/p.251)

163. Ans. (c) Cerebellum (Ref Ganong, 25th ed/p.248)

• Cerebellum plays an integral role in posture maintenance 164. Ans. (c) Resting tremor

~M_a_m_m_il_la_ry_bo_d_Y~r----~1 Anterior nuclei of thalam; aj 170. Ans. (c) Caudate nucleus (Ref Ganong, 25th ed/p.269)

171. Ans. (b) Amygdala (Ref Guyton, 13'" ed!p.760)

• Amygdala is also called as the "window through which limbic system sees the world"

(Ref Ganong, 25th ed/p.251)

172. Ans. (d) Hypothalamus

Thalamus, Hypothalamus and Limbic System 165. Ans. (d) Supra chiasmatic nucleus (Ref Ganong 25th ed p.307) Suprachiasmatic nucleus (SCN)

• Concerned with circadian rhythms - the normal 24 hour rhythms of humans • It is the "dominant pacemaker" that regulates circadian rhythm • Bilateral destruction of the SCN results in a loss of most endogenous circadian rhythms including wake-sleep behavior 166. Ans. (b) VPL (Ref Ganong, 25th ed/p.269)

• Ventral posterior lateral (VPL) and ventral posteromedial nuclei (VPM) - Transmit somatosensory information to sensory cortex 167. Ans. (c) Ventral anterior (Ref Ganong, 25th ed/p.269)

(Ref Ganong, 25th ed/p.307)

• Reward center - located along the course of the medial forebrain bundle in lateral and ventromedial nuclei of the hypothalamus • Punishment center - located in central gray area surrounding the aqueduct of Sylvius and periventricular zones of the hypothalamus and thalamus 173. Ans. (a) Amygdala (Ref Guyton, 13'" ed!p.760) Kliiver-Bucy Syndrome

• Occurs due to Bilateral Ablation of the Amygdala • Characterized by, • Not able to recognize objects by sight - Visual agnosia • Tendency to examine objects excessively by mouth Hyperorality • Compulsion to intensively explore the immediate environment - Hypermetamorphosis • No longer show fear or anger, even when such a reaction is appropriate - Placidity • Eat excessively even when not hungry, or may eat objects that are not food - Hyperphagia • Augmentation in sexual behavior - Hypersexuality

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174. Ans. (a) Ventromedial nucleus of hypothalamus (Ref Ganong, 25th ed/p.308)

• Feeding center - lateral nucleus of hypothalamus • Satiety center - ventromedial nucleus of hypothalamus

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Cerebral Hemispheres 175. Ans. (c) Suprachiasmatic nucleus (Ref Ganong, 25th ed/p.309)

184. Ans. (d) Inferior colliculus

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177. Ans. (b) Continues with cycle length of >24 hours

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• Experiments were performed in which subjects stay in in isolation in specially constructed rooms without any clues regarding the time of day in the outside world-no clocks, windows, radios, televisions • Results of such studies the circadian rhythm persists, but its duration varies among subjects and is typically slightly longer (e.g. 25 hours) • When they were reexposed to the external day-night cycle, the normal circadian rhythm resumes

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(Ref Ganong 25th ed p.275)

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(Ref Ganong, 25th ed!p.766) 192. Ans. (c) Hypothalamus

199. Ans. (b) 4 - 8 Hz

(Ref Ganong, 25th ed!p.273)

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(Ref Ganong, 25th ed!p273.)

200. Ans. (d) Produces a - block on ECG

193. Ans. (a) Deep sleep

(Ref Ganong, 25th ed!p.273)

(Ref Ganong, 25th ed/p.274)

• Delta waves are seen during deep sleep 194. Ans. (c) Stage 2 NREM

(Ref Ganong, 25th ed!p.273)

Stage 2 NREM • Waves with frequency 12 - 14 Hz called sleep spindles seen • high voltage biphasic waves called K complexes also seen 195. Ans. (a) Stage 1 sleep

(Ref Ganong, 25th ed/p.273)

• Reticular activating system (RAS) • Is a polysynaptic pathway • It plays an important role in promoting wakefulness (arousal) • It receives collaterals from sensory pathways • It is also involved in regulation of heart rate, blood pressure, and respiration • Alpha block - When attention is focused on something, the alpha rhythm is replaced by fast, irregular low-voltage activity • RAS have no role in mediating alpha block 201. Ans. (c) Pineal gland

Stage 1 NREM

(Ref Ganong, 25th ed!p.278)

• Transition between waking and sleep • EEG shows low frequency (4 - 7 Hz) theta waves 196. Ans. (a) Alpha waves

• Melatonin is the N-acetylated product of serotonin found in the pineal gland 202. Ans. (b) Pinealocytes

(Ref Ganong, 25th ed/p.273)

Alpha wave • Frequency is 8 - 13 Hz • Are most prominent over parieto-occipital areas • Seen when the patient is resting with the eyes closed Comparison of Night Terrors and Nightmares Night terrors

Nightmares

Stage of sleep

NREM

REM

Consolability

Poor

Good

Amnesia for event

Yes

No

Interest in returning to sleep

High

Low

(Ref Ganong, 25th ed!p.278)

203. Ans. (c) Regulates the circadian day night rhythm (Ref Ganong, 25th ed!p.278)

• Melatonin receptors are MT 1 and MT 2 receptors • MT 1 -Promotes sleep • MT 2 - Synchronize circadian rhythm

Learning and Memory 204. Ans. (a) Long-term potentiation

(Ref Ganong, 25th ed!p.284)

• A brief high-frequency train of stimuli (a tetanus) gives rise to a long-lasting increase in the amplitude of the excitatory postsynaptic potentials (EPSPs) - termed as long term potentiation

Language and Speech 213. Ans. (a) Inability to recognize faces (Ref Ganong, 25th ed!p.294)

205. Ans. (a) Synaptic network

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Glutamate release in hippocampus - Has got a role in synaptic plasticity (learning and memory) Relaxation of lower esophageal sphincter (LES) - defective release of nitric oxide in lower end of esophagus leads to Achalasia cardia

It is the most potent vasodilator known Like calcitonin, CGRP is also present in large amounts in the parafollicular C cells of the thyroid gland It is usually present along with Substance P in heart, brain, lung and GI tract CGRP acts through a G protein-coupled receptor combined with receptor activity-modifying protein RAMP I Actions of CGRP It is a powerful vasodilator of coronary circulation Suppression of feeding (satiety promoting) Causes pain Descent of testis in male fetus - CGRP released from genitofemoral nerve is an important factor for descent of testis

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600 pg/mL c. >100 pg/mL d. >40 pg/mL 56. In a measurement of cardiac output using the Fick principle, the 0 2 concentrations of mixed venous and arterial blood are 16 and 20 ml. 100 ml- 1, respectively, and the 0 2 consumption is 300 ml min- 1• The cardiac output in liters min- 1 is: (JIPMER May 2019) a. 5 b. 8 c. 9 d. 7.5 57. True about Bowditch's effect of heart (JIPMER Nov 2018) a. Increased in HR decrease relaxation b. Increased in HR increase relaxation c. Increased in HR decrease contraction d. Increased in HR increases contraction

58. Which of the following best describe 'Anrep effect'? (JIPMER Nov 2018) a. Increased preload decreases cardiac contractility b. Increased afterload increases cardiac contractility c. Increased preload decreases cardiac relaxation d. Decreased afterload decreases cardiac relaxation 59. Which of the following statement is/are true regarding Fick principle of measurement of cardiac output: a. Cardiac output is calculated by amount of oxygen consumed by whole body per unit mass divided by A-V Oxygen difference across the lung b. Oxygen concentration in artery is measured by passing catheter to Pulmonary artery c. Mixed venous blood is measured by inserting catheter into pulmonary artery d. Rate of oxygen absorption by the lungs is measured by spirometry e. For oxygen content of artery, any artery of body can be chosen 60. Cardiac output is determined by (Recent Question 2012) a. Ratio of organ to total peripheral resistance b. Mean stroke volume c. Mean BP d. Contractility of heart (Recent Question 2012) 61. Ejection fraction is a. SV I EDV b. EDV/SV c. EVS/EDV d. SV/ESV 62. What is the normal left ventricular ejection fraction? (Recent Question 2012) a. W% b. ~% c. 50% d. 65% 63 . Basal Cardiac output in an adult in nearly (PG! Nov 2015) a. 7.5 liter b. 5 liter c. 12 liter d. 10 liter 64. In a patient with cardiac output 5 liters/minute and body surface area 1. 7 m2 what will be the cardiac index (PG! June 2015) a. 3 liter/min/m 2 b. 4 liter/min/m 2 c. 5 liter/min/m 2 d. 2.5 liter/min/m 2 2 e. 4.7 liter/min/m (Recent Question 2012) 65. Normal cardiac index is a. 3.2 b. 2.8 c. 2.4 d. 4.4 66. Stroke volume is increased by (Recent Question 2015) a. Increased end - diastolic and end - systolic volumes b. Decreased end - diastolic and end - systolic volumes c. Increased end - diastolic volumes and Decreased endsystolic volumes d. Decreased end - diastolic volumes and increased endsystolic volumes 67. Which scientific principle is the basis of thermodilution method used in measurement of cardiac output a. Hagen - Poiseuille principle (A IIMS May 2012, AI 2012) b. Bernoulli's principle c. Stewart - Hamilton principle d. Universal gas equation

68. Direct fick method of measuring cardiac output requires estimation of? (Recent Question 2013) a. 0 2 content of arterial blood b. 0 2 content of venous blood c. 0 2 consumption per unit time d. All of the above 69. What will be cardiac output if 400 mg of dye is given intravenously and the concentration in blood is 2 mg/L after 1st passage time of 40 seconds (Recent Question 2015) a. 1.5 L b. 3 L c. 5 L d. 6 L 70. Volume determining preload is(JIPMER 2010, PGI June 1998) a. End diastolic volume of ventricles b. End systolic volume c. Volume of blood in aorta d. Ventricular ejection volume 71. End diastolic volume increases due to (AIIMS Nov. 2012) a. Increase in intrapericardial pressure b. Decrease in ventricular compliance c. Decrease in total blood volume d. Increase in negative intrathoracic pressure 72. Cardiac output decreases during (AI 2012) a. Moderate increase in environmental temperature b. Anxiety and excitement c. Eating d. Standing from lying down position 73. Cardiac output in increased by all except a. Exercise (Recent Question 2013) b. Pregnancy c. Hot atmosphere d. Standing from lying down 74. Total cardiac output doesn't change during a. Sleep (JIPMER 2011) b. From supine to standing position c. Exercise d. Arrhythmias 75. Preload is increased by (Recent Question 2012) a. Increased blood volume b. Increased total peripheral resistance c. Standing d. Sitting 76. Starlings law implies (Recent Question 2012) a. Increased VR -7 increased CO b. Increased discharge -7 increased CO c. Increased HR -7 increased CO d. Increased BP -7 increased CO 77. Healthy adult cardiac reserve is (Recent Question 2013) a. 50-100% b. 100-200% c. 200- 250% d. 300-400%

Coronary Circulation 78. Major portion of coronary blood flow occurs during(Recent Question 2013) a. Systole b. Diastole c. Not related to phases d. It is variable

79. Myocardial oxygen demand depends upon- (PGI May 2015) a. Preload b. Afterload c. Intramyocardial tension d. Blood Hb concentration 80. True regarding myocardial 0, demand? a. Inversely related to heart r~te (AIIMS May 2011) b. Has constant relation to external cardiac work c. Directly proportional to duration of systole d. Is negligible at rate 81. Regulation of coronary circulation (Recent Question 2012) a. Autonomic b. Autoregulatory c. Hormonal d. Sympathetic 82. Coronary blood flow regulated by (Recent Question 2015) a. Sympathetic adrenergic system b . Sympathetic cholinergic system c. Local muscle action and reflexes d. Parasympathetic system

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83. Mean arterial pressure is calculated as (AIIMS Nov 2011, 2006) a. (SBP + 2DBP)/3 b. (DBP + 2SBP)/3 c. (SBP + 3DBP)/2 d. (DBP + 3SBP)/2 84. Mean arterial pressure depends upon a. Cardiac output (Recent Question 2012) b. Cardiac output and peripheral resistance c. Arterial compliance d. Peripheral resistance 85. Peripheral resistance is best indicated by (AIIMS Nov. 2013) a. Diastolic BP b. Systolic BP c. Mean BP d. Pulse pressure 86. SI unit for measuring Blood pressure is (All India Dec 2013) a. Torr b. Mm Hg c. kPa d. Barr 87. BP is measured in (Recent Question 2015) a. Axillary artery b. Carotid artery c. Brachia! artery d. Radial artery 88. The blood pressure measured by a sphygmomanometer (JIPMER 2010, AI 2008, 2001) a. Is lower than the intraarterial pressure b. Is higher than the intraarterial pressure c. Is same as the intraarterial pressure d. Is the same with different cuff sizes 89. Which of the following is not true about measurement of blood pressure? (AIIMS May 2014) a. The bladder of the blood pressure cuff should cover more than 80% of the arm circumference b. The blood pressure cuff should be at a higher level than the heart c. Patient should be in resting position d. Cuff should be tied over upper arm 90. The basis of Korotkoff sound is related to a. Aortic valve closure (Karn 2011, Corned 2009) b. Production of heart sound c. Arterial turbulence d. Arterial valve expansion

91. Hormone involved in regulation of BP

105. Each hemoglobin molecule contains how many globin

(Recent Question 2015) b. Angiotensin - II a. Serotonin d. Prostaglandin c. Dopamine 92. Short term BP regulation exerted through kidney by

(Recent Question 2013)

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• Phase 0 is the early depolarization characterized by opening of voltage-gated sodium channels leading to sodium influx

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24. Ans. (c) Atrial contraction

Ref Ganong, 25th ed!p.521

Ref Ganong, 25th ed!p.525

• In the order of importance, causes of pacemaker potential are, • Decrease in K+permeability • Pacemaker current (Ir) or "funny" current • Calcium influx through T-type calcium channels

• PR interval • From the onset of P wave to the beginning of QRS complex • Duration - 0.12 to 0.20 sec • Denotes atrial contraction and Atrioventricular (AV) conduction time

ECG

25. Ans. (d) Ventricular depolarization

18. Ans. (b) Short QT interval, (d) Osborn wave, (e) Prominent Uwave (Ref Ganong 25th ed p. 523)

• Hypercalcemia is characterized by short QT interval, Osborn wave (positive deflection at J point) and Prominent Uwave 19. Ans. (c) If there are 3 large boxes between R-R, then heart rate is 90 beats/ min (Ref Ganong 25th ed p.523)

• If there are 3 large boxes between R-R, then heart rate is 300/3 which is 100 beats/min

Ref Ganong, 25th ed/p.523 26. Ans. (b) 0.40 - 0.45

Ref Ganong, 25th ed/p.523

QT interval • From the onset of Q wave to the end of T wave • Duration - 0.35 to 0.43 sec • Denotes ventricular depolarization and repolarization events 27. Ans. (a) 0.12 - 0.2 sec

Ref Ganong, 25th ed/p.523

20. Ans. (b) - 30 to 110°

28. Ans. (a) Atrial fibrillation · Ref Ganong, 25th ed/p.524

• Normally, the QRS axis ranges from -30° to +100° • Axis more negative than -30° is called left axis deviation • Axis more positive than + 100° is called right axis deviation

Ref Ganong, 25th ed/p.524

• P wave is absent in atrial fibrillation • Instead of p waves, only fibrillatory f waves are seen • P wave is absent also in hyperkalemia

21. Ans. (a) I + III = II 29. Ans. (b) Left side of interventricular septum Ref Ganong, 25th ed/p.524

Einthoven's law - states that the sum of the potentials in leads I and III equals the potential in lead II. Lead I + III = Lead II 22. Ans. (a) 1 Ref Ganong, 25th ed/p.524

Ref Ganong, 25th ed/p.525

• Ventricular depolarization begins from Left side of interventricular septum • Last parts of the heart to be depolarized are posterobasal portion of the left ventricle, the pulmonary conus, and the uppermost portion of the septum. These are the areas which repolarize first

Lead III= Lead II - Lead I= (2 - 1) = 1 30. Ans. (b) Endocardium to epicardium 23. Ans. (a) P - wave

Ref Ganong, 25th ed/p.523 Ref Ganong, 25th ed/p.523

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Ref Ganong, 25th ed/p.540

• Maximum ventricular pressure around 140 mm Hg is achieved during rapid ejection phase 44. Ans. (d) Q wave second heart sound

Total electromechanical systole (QS 2)

50. Ans. (c) Ventricular filling Ref Ganong, 25th ed/p.540

51. Ans. (d) Atrial contraction

Ref Ganong, 25th ed!p.541 Onset of the QRS complex to the closure of aortic valves (S 2 )

Left ventricular ejection time (LVET)

beginning of the carotid pressure rise to dicrotic notch

Pre-ejection period (PEP)-lsovolumetric contraction

difference between QS 2 and LVET

Ref Ganong, 25th ed!p.539

52. Ans. (c) Closure of aortic valve Ref Ganong, 25th ed!p.540

• Closure of aortic and pulmonary valve causes a characteristic notch called dicrotic notch or incisura in pulse wave tracing 53. Ans. (d) Closure of tricuspid valve Ref Ganong, 25th ed!p.542

"The ratio PEP/LVET is normally about 0.35"

JVP 'Characteristics waveforms

45. Ans. (c) 25 - 35 Hz Ref Ganong, 25th ed!p.541

Heart sounds

I Cause

ICharacteristics

First heart sound (S)

• closure of AV valves

• long and soft • Duration (0.15 s) • frequency is 25-45 Hz

Second heart sound(S)

• closure of the semi lunar valves

• short, loud, high pitched • Du ration is 0.12 s • frequency is SO Hz

Third heart sound (S 3)

• vibrations in cardiac wall due to the inrush of blood during rapid filling phase of ventricular diastole

• short, soft and low pitched sound • Du ration is 0.1 s

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• Due to right atrial contraction (atrial systole) • it peaks just before the first heart sound

cwave

• Due to bulging of tricuspid valve into right atrium during isovolumetric contraction • Occurs during the first heart sound

x descent

• Denotes fall in right atrial pressure during atrial relaxation • ends just before the second heart sound

vwave

• Due to right atrial filling (atrial diastole) • V wave peaks just after the second heart sound

y descent

• Due to rapid emptying of right atrium once tricuspid valve opens • Correlates with the third heart sound

54. Ans. (a) Atrial contraction Ref Ganong, 25th ed/p.542

Cardiac Output

63. Ans. (b) 5 litre Ref Ganong, 25th ed!p.544

55. Ans. (c) >100 pg/ml (Ref Ganong 25th ed p.544)

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• Cardiac index= 5/1.7 = 3 liter/min/m 2 300 ml/min

65. Ans. (a) 3.2

20-16 ml/dL Ref Ganong, 25th ed!p.544

• So, Cardiac output= 7.5 L/min

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Ref Ganong, 25th ed/p.

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Important points to be noted in this graph are : • In saline filled lungs, surface tension forces are absent because saline abolished the surface tension forces • So, the only opposing force in saline filled lung is the elastic forces of the lung tissues • Carefully note that there is no hysteresis with saline inflation • In air filled lung, hysteresis is seen • In air filled lung, both the opposing forces are present • The difference between these two curves is the surface tension forces, which is the major opposing force for lung distension

Types of Compliance •

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There are three types of compliance one have to clearly understand. They are: • Static compliance • Dynamic compliance • Specific compliance

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As a part of normal ageing. Compliance of lung increases in old age Emphysema • In emphysema there is loss of elastic recoil of lung • Emphysematous lung is easy to inflate (overdistension) but because of the loss of elastic recoil, additional effort must be given to force air out of lung Flail chest Sternotomy

Conditions causing decrease in compliance (Curve shifted downward and to the right) "Any condition that cause lung stiffness or that opposes lung expansion always decreases lung compliance"

•

Transpulmonary pressure (cm H2 0)

Fig. Conditions that alter compliance curve

Whenever the term compliance is used alone, it always means static compliance

• • • • • •

Pulmonary fibrosis • In pulmonary fibrosis, elastic fibers of lung are replaced by stiff collagen fibers Consolidation Pulmonary edema Pneumothorax Obesity Kyphoscoliosis Ankylosing spondylysis

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PCWP is usually measured using a balloon-tipped, multilumen catheter called Swan-Ganz catheter. It is shown below

The catheter is usually into a peripheral vein and then advancing it into the right atrium, right ventricle, pulmonary artery, and then into a branch of the pulmonary artery until it lodges (wedges) in one of its smallest branches The balloon is then inflated and the pressure is measured using a pressure transducer The same catheter is also useful to measure cardiac output by the thermodilution technique

Mean Pulmonary capillary wedge 9 mm Hg (Range is 4-12 mm Hg)

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Transport of Carbon Dioxide in Dissolved form

• • •

7% of co2is transported in dissolved form Total C0 2 content of arterial blood is 48 mL C0/100 mL out of which 2.4 mL of C0 2 is in dissolve form Total C0 2 content of venous blood is 52 mL C0/100 mL out of which 2.7 mL ofC0 2 is in dissolve form

Carbon Dioxide Dissociation Curve

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Characterized by prolonged inspiratory spasm

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59. Ans. (c) V/ Q is high

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(Ref Ganong, 25th ed!p.639)

• In clinical practice, carbon monoxide is the gas of choice for measuring diffusion capacity because it is the diffusion limited gas • The procedure is called diffusing capacity of the lung for carbon monoxide or DLCO 67. Ans. (d) 300-400 ml/min/mm Hg (Ref Ganong, 25th ed!p.640)

• Normal value of DLCO is 25 mL/min/mm Hg • Diffusion coefficient of 0 2 is about 1.23 times that of CO • So, Diffusing capacity for oxygen is 25 * 1.23 = 30 mL/min/ mmHg • Diffusion capacity of C0 2 is 400 ml/min/mm Hg

68. Ans. (d) Polycythemia

• 100 mm Hg= 0.3 ml 0 / 100 ml • X = 0.25 ml 0/ 100 ml • So, X = 0.25 * 100/0.3 = 83 mm Hg

(Ref Ganong, 25th ed!p.639)

• DLCO is increased in polycythemia 74. Ans. (b) Increased 0 2 delivery at tissue and uptake at lung

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Transport of Gases

(Ref Ganong, 25th ed/p.640)

• Hemoglobin is the oxygen carrier protein • It takes up oxygen from lungs and deliver it to tissues

69. Ans. (b) There is less decrease in 2,3 DPG

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Exercise has gained significant interest in recent times because: Exercise stress tests are useful in evaluation of cardiovascular and respiratory problems • Exercise is employed therapeutically in the treatment of diabetes mellitus and other related disorders • Two types of exercises are there namely: • Isotonic exercise • Isometric exercise

• • •

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(Ref Guyton, 13t1• ed/p.1086)

• During exercise- Cardiac output increases by increase in stroke volume • Since Stroke volume =End Disatolic Volume - End Systolic Volume, it is increased by either increase in EDV or decrease inESV

• Both isotonic and isometric are strengthening exercises • Since isometric exercises increases both systolic and diastolic BP, it is always the isotonic exercises which are preferred ones. 8. Ans. (c) Creatine phosphate

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Hypothalamus secretes certain factors that control the release of anterior pituitary hormones Such releasing factors of hypothalamus are also called as "hypothalamic-hypophysiotropic hormones" Hypothalamus communicates with anterior pituitary through vascular connections. Such vascular connections are called as Hypothalamohypophyseal portal system Hypothalamo-hypophyseal portal system •

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Thyroid Stimulating Hormone (TSH) - Anterior Pituitary

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Normal insulin-glucagon molar ratio on a balanced diet is 2.3 After infusion of arginine, this ratio increases to 3. This is simply because arginine increases the secretion of both insulin and glucagon Now consider this scenario - "Infusion of arginine after 3 days of starvation" Remember that glucagon secretion peaks during 3'd day of • starvation • The ratio actually decreases to 0.3 • During starvation, glucagon increases and it uses the amino acid arginine for conversion to glucose (Gluconeogenesis) During starvation, the ratio decreases In well fed state, the ratio increases

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Somatostain in Pharmacology •

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Enzyme names 3pHSD-3b-hydroxysteroid dehydrogenase P450c17-17 a-hydroxylase/17, 20 lyase P450c21-21 hydroxylase p450AS- aldosterone synthase P450C11 P-11 p hydroxylase

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Dexamethasone can 't suppress cortisol secretion both in low and high dose (cortisol >5 ~tg /dl)

Now, dexamethasone has little additional effect

Only high dose dexamethasone can suppress cortisol

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adrenal nodule

(cortisol 20 µg/dl exactly 30-60 min after cosyntropin stimulation

Mineralocorticoids - "Aldosterone " • •

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Aldosterone is the major mineralocorticoid produced from zona glomerulosa Other adrenal steroids with mineralocorticoid activity are, • Deoxycorticosterone (DOC) • Corticosterone (also called as Compound B) • Cortisol Half-life of aldosterone is short. It is about 20 min

•

Regulation of Aldosterone Secretion •

Surgery Anxiety Standing Hemorrhage

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Conditions that increase aldosterone secretion are, • High potassium intake • Low sodium intake - activates Reni n angiotensin aldosterone system (RAAS)

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Most important functions of the kidneys are the regulation of, • Water homeostasis • Electrolyte composition • Regulation of extracellular volume (blood pressure) • Acid-base homeostasis The functional unit of kidney is the nephron Each human kid ney has approximately I m illion neph rons

Types of Nephron

Renal cortex

STRUCTURE OF A NEPHRON

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These are the cells mainly involved in acid base balance They have an abundant conce ntration of carbonic anhyd rase enzyme like RBCs Aldosterone acts in intercalated cells to increase H+ ion secretion in urine Are of two types namely type A and B in tercalated cells Type A intercalated cells secrete H+ ion. They are up regulated during conditions of acidemia Type B intercalated cells secrete HC0 3- ion. They are up regulated during conditions of alkalemia

• • • •

Anion Gap • • •

Ideally, the concentrations of anions and cations in plasma must be equal to maintain electrical neutrality Routine serum electrolyte determ inations m easure essentially all cations but only a fraction of the anions This disparity between the total cation concentration and the total anion concentration is termed the anion gap Anion gap = [Na+] - [Hco 3- + c1-1= [140 mEq/L] - [25 mEq/L + 105 mEq/L] Anion gap= 10 mEq/L

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• Is slow but effective • It includes Increased excretion of fixed Was titratable acid and NH 4 adaptive increase in NH 3 synthesis • Increased expression of type A intercalated cells that secretes Win urine

Metabolic Alkalosis •

Primary problem in metabolic acidosis is loss of

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Causes of metabolic alkalosi s are : •

Vomiting of Gastric Contents (loss of W)

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Hyperaldosteronism (loss of Win urine)

w· or addition of Hco 3- causing increase in pH

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Excessive ingestion of antacids

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Volume contraction alkalosis - administration of thiazide diuretics

Compensations seen in metabolic alkalosis Respirator}' Comf)ensation

Renal Comf)ensation

• Hypoventilation - elevates pC0 2 and normalizes pH • It is very limited because of the accompanying decreased arterial p0 2 stimulates respiratory center

• Is slow but effective • Decreased W secretion by the renal tubule s • Increased expression of type B intercalated ce lls that secretes HC0 3- in urine

Respiratory Acidosis •

Primary problem in respiratory acidosis is increased pCO, that causes an increase in Wand lowering of blood pH

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Causes are: • Depression of respiratory center by drugs like opioids

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Damage to respiratory centers

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Weakening of respiratory muscles - polio, Guillain - Barre syndrome

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Impaired gas diffusion - chromic obstructive pulmoonany disease

Compensation is mainly renal which includes, •

Increased excretion of Was a titratable acid and NH 3

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Increased reabsorption of new HCQ 3-

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Increased expression of type A intercalated cells that secretes Win urine

Respiratory Alkalosis •

Primary problem in respiratory alkalosis is decreased pC0 2 that causes an decrease in Wand increase in blood pH

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Causes are, •

•

Seen in individuals ascend to high altitude

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Psychogenic hyperventilation

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Overventilation with mechanical ventilators

Compensation is mainly renal which includes: •

Decreased excretion of Was titratable acid and NH4

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Increased expression of type B intercalated cells that secretes HC0 3- in urine

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• Glomerular hydrostatic pressure = 60 • Bowman's capsule colloid osmotic pressure = 0 Forces Opposing Filtration (mm Hg) • Bowman's capsule hydrostatic pressure= 18 • Glomerular capillary colloid osmotic pressure= 32 Net filtration pressure= 60- 18 - 32 = 10 mm Hg • Since Glomerular capillary colloid osmotic pressure oppose filtration, its decrease actually increases GFR 7. Ans. (c) Decreases capillaries

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(Ref Guyton Textbook of medical physiology, 11th ed, p.343)

Constriction of efferent arteriole effects: • Constriction of efferent arteriole has biphasic response on GFR • If there is less than threefold increase in resistance - GFR increase because of increase in PG • If there is more than threefold increase in resistance - GFR decreases because of decrease in RBF and increase in colloid osmotic pressure • Efferent arteriolar constriction reduces peritubular capillary hydrostatic pressure, which increases net tubular reabsorption

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• Increase in proteins that escape filtration in glomerular capillaries RISES oncotic pressure in the glomerular capillaries and peritubular capillaries

17. Ans. (a) 125 mL/min (Ref Ganong, 25th ed!p.676)

• Normal GFR is 125 ml/min or 180 L/day 8. Ans. (d) Glomerular mesangial cells

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• If the clearance of a substance is greater than GFR, then that substance must be secreted • If a substance is completely cleared from the renal blood in one pass through the kidney, then its clearance is equal to renal plasma flow. Example of such substance is PAH

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• The fluid in the descending limb of the loop of Henle becomes hypertonic because it is permeable to water • It is this hypertonic fluid going to reach ascending limb of the loop of Henle

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58. Ans. (b) Collecting duct (Ref Ganong, 25th ed/p.685)

• In kidney, counter current system is seen in the loop of Henle and vasa recta in renal medulla • Collecting duct is not a part of counter current system 59. Ans. (a) At the loop of Henle, there is counter current mechanism (Ref Ganong, 25th ed!p.685)

60. Ans. (b) Na (Ref Ganong, 25th ed/p.685)

• Sodium ions are most important as far as medullary hyperosmolarity is concerned 61. Ans. (d) Urea has no role

68. Ans. (a) Juxtaglomerular cells (Ref Ganong, 25th ed!p.672)

69. Ans. (c) Liver (Ref Ganong, 25th ed/p.696)

• Angiotensinogen is secreted by liver 70. Ans. (b) Lung (Ref Ganong, 25th ed!p.696)

• Angiotensin converting enzyme is present in pulmonary capillary endothelium. It converts Angiotensin I to Angiotensin II 71. Ans. (d) Vasodilation (Ref Ganong, 25th ed!p.696)

• Angiotensin II is a powerful vasoconstrictor (Ref Ganong, 25th ed!p.686)

• 50% of medullary hyperosmolarity is due to urea 62. Ans. (b) Inner medulla (Ref Ganong, 25th ed!p.686)

• Maximum osmotic gradient (1200 mOsm/L) is seen at the tip of the loop of Henle 63. Ans. (c) 50 mOsm/L

72. Ans. (d) Vasopressin (Ref Ganong, 25th ed!p.696)

• Angiotensin II and aldosterone have little effect on sodium concentration • Vasopressin is the major regulator of sodium concentration under normal conditions 73. Ans. (d) Loop of Henle

(Ref Ganong, 25th ed!p.686)

(Ref Ganong, 25th ed!p.699)

• Normal range of urine osmolality is 50 - 1400 mOsm/L

• Macula densa - These are the specialized epithelial cells of thick ascending limb of loop of Henle

64. Ans. (a) SO - 1400 (Ref Ganong, 25th ed!p.686)

• To conserve potassium in hypokalemia, acid secretion increases • All acidotic conditions increase renal acid secretion

74. Ans. (c) Decreased blood pressure (Ref Ganong, 25th ed!p.700)

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• Major stimulus for renin release is Decreased blood pressure • Once released, renin converts Angiotensinogen to Angiotensin I • Angiotensin I to Angiotensin II is converted by Angiotensin converting enzyme • Angiotensin II releases aldosterone from adrenal cortex • Together this system Renin Angiotensin Aldosterone System (RAAS) increase bloop pressure

• Aldosterone increases acid secretion in kidney 82. Ans. (a) [Na+] - [Cl-] - [Hcm-1 (Ref Ganong, 25th ed!p.715) Anion gap= [Na+] - [HC0 3 -+

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[140 mEq/L] - [25 mEq/L + 105 mEq/L] Anion gap = 10 mEq/L

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Substrate

Catalytic Function or Products

Trypsin

Enteropeptidase

Proteins and polypeptides

Cleave peptide bonds of basic amino acids

Chymotrypsins

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Proteins and polypeptides

Cleave peptide bonds of aromatic amino acids

Elastase

Trypsin

Elastin

Cleaves bonds of aliphatic amino acids

Carboxypeptidase A

Trypsin

Proteins and polypeptides

Cleave bonds of aliphatic or aromatic amino acids

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Cleave bonds of basic amino acids

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Triglycerides

Monoglycerides and fatty acids Cholesterol

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a. Tone of contraction is related to amplitude of stimulus b. Tone of contraction is related to frequency of stimulus c. Frequency of contraction is 6/min d. Threshold of contraction is -50 m V

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Stomach Duodenum Jejunum Large intestine

Most important site in Organ (Photograph) production of Gastrin?

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Protein > carbohydrate (Recent Question 2012) b. Fat > carbohydrate > Protein c. Protein > Fat > carbohydrate d. Protein > Fat > carbohydrate 42. Maximum postprandial motility is seen in a. Ascending colon (AIIMS May 2011, Nov 2008) b. Transverse colon c. Descending colon d. Sigmoid colon 43. Migrating motor complex is due to which GI hormone

31. Late emptying of gastric content due to presence of hypertonic and acidic content in the duodenum is due to:

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(Recent Pattern Question 2020) a. Gastrocolic reflex b. Gastroileal reflex d. Myenteric reflex c. Enterogastric reflex Which of the following substance causes anterograde relaxation during gut peristalsis: (Recent Pattern Question 2019) b. VIP a. Substance P c. Serotonin d. Acetyl choline Slow waves are generated by (AIIMS Nov 2017) a. Myenteric neurons b. Smooth muscle c. Interstitial cells of Cajal d. Parasympathetic neurons Deglutitive inhibition (JIPMER May 2017) a. Wave of inhibition preceding peristalsis b. Inhibition occurs simultaneously with peristalsis c. Inhibition occurs after peristalsis d. Wave of stimulation preceding peristalsis Pacemaker is formed by which of the following cells in GIT(Recent Question 2013) a. P- cells b. Oxyntic cells d. Parietal cells c. Cajal cells GIT pacemaker is located(Recent Question 2013) a. Esophagus b. Stomach c. Duodenum d. Jejunum Gastric emptying is delayed by all expect a. Fat in duodenum (Recent Question 2013) b. Acid in duodenum c. Gastrin d. Secretin Gastric emptying is mainly regulated bya. Neural reflexes (Recent Question 2012) b. Enteric reflexes c. Local hormones produced in stomach d. Local hormones produced in duodenum What is responsible for clearing & flushing food from the intestinal lumen in the interdigestive Period(Recent Question 2015) b. Migrating motor complexes a. Gastrin d. CCK. c. Secretin

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(Recent Question 2015) a. Gastrin b. Motilin c. CCK d. VIP Intestinal motility is increased by (Recent Question 2012) a. Secretin b. Gastrin c. CCK d. Motilin In peristalsis following is involved except (Recent Question 2015) a. NO b. Substance P c. Noradrenaline d. VIP Which of the following is involved in peristalsis by causing relaxation (Recent Question 2015) a. Substance P b. Acetylcholine c. VIP d. Noradrenaline Slow waves/BER maximum in (Recent Question 2012) a. Stomach b. Ileum c. Colon d. Rectum Submucosal plexus of GIT (Recent Question 2013) a. Myenteric plexus b. Auerback's plexus c. Meissner's plexus d. Extrinsic nerve Myentric plexus is present in (Recent Question 2012) a. Muscularis externa b. Sumucosa c. Mucosa d. Serosa Inhibition of Myentric plexus results in a. Hyperacidity (Recent Question 2013) b. Diarrhea c. Decreased gut motility d. Increased secretions Secretion in GIT is Controlled by a. Myenteric plextus b. Auerbach's plexus c. Meissner's plexus d. Extrinsic nerve Parasympathetic nerve stimulation results in a. Sphincter closure of gallbladder (PGI Nov 2015) b. Increased peristalsis c. Decreased GIT motility d. Detrusor muscle relaxation e. Gallbladder musculature contraction

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22. Ans. (b) CCK (Ref Ganong, 25th ed/p.460)

• Factors that inhibit gastric emptying • Fats, carbohydrates, and acid in the duodenum • Hyperosmolality of the duodenal contents • Cholecystokinin • Peptide YY • This is mediated through a reflex called Enterogastric reflex 32. Ans. (b) VIP

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(Ref Ganong, 25th ed/p.476)

• Stimulator of secretin is acidic chyme • In response to acidic chyme in duodenum, secretin causes pancreatic juice rich in bicarbonate

• Enterokinase catalyzes the cleavage of one specific peptide bond in trypsinogen resulting in formation of trypsin

57. Ans. (b) Increases small intestine peristalsis (Ref Ganong, 25th ed/p.471)

• CCK Increases small intestine peristalsis 58. Ans. (b) Antrum

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80. Ans. (a) Duodenum

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97. Ans. (c) Citrus fruits (Ref Ganong, 25th ed/p.484)

• Citrus fruits containing vitamin C is very effective in increasing iron absorption

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98. Ans. (b) Hepcidin (Ref Ganong, 25th ed/p.483)

• Hepcidin is the crucial molecule in iron metabolism, linking body stores with intestinal iron absorption

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107. Ans. (b) Has anorexic effect (Ref Ganong, 25th ed/p.485)

108. Ans. (c) Ghrelin (Ref Ganong, 25th ed/p.485)

109. Ans. (a) High

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(Ref Ganong, 25th ed!p.485)

• Obesity is characterized by leptin resistance

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