Physiology

Physiology

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Linda S. Costanzo, Ph.D.

Professor of Physiology and Biophysics

Medical College of Virginia

Virginia Commonwealth University

Richmond, Virginia

Physiology

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Acquisitions Editor: Crystal Taylor

Product Manager: Stacey L. Sebring

Designer: Holly Reid McLaughlin

Compositor: MPS Limited, A Macmillan Company

Copyright © 2011 Lippincott Williams & Wilkins

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The publisher is not responsible (as a matter of product liability, negligence, or otherwise) for any

injury resulting from any material contained herein. This publication contains information relating to

general principles of medical care that should not be construed as specific instructions for individual

patients. Manufacturers’ product information and package inserts should be reviewed for current infor￾mation, including contraindications, dosages, and precautions.

Printed in China

First Edition, 1995

Second Edition, 1998

Third Edition, 2003

Fourth Edition, 2007

Library of Congress Cataloging-in-Publication Data

Costanzo, Linda S., 1947-

Physiology/Linda S. Costanzo. —5th ed.

p. ; cm. —(Board review series)

Includes bibliographical references and index.

ISBN 978-0-7817-9876-1 (alk. paper)

1. Human physiology—Examinations, questions, etc. I. Title. II. Series: Board review series.

[DNLM: 1. Physiological Phenomena—Examination Questions. 2. Physiology—Examination Questions.

QT 18.2 C838p 2011]

QP40.C67 2011

612’.0076—dc22

2010018984

The publishers have made every effort to trace the copyright holders for borrowed material. If they

have inadvertently overlooked any, they will be pleased to make the necessary arrangements at the first

opportunity.

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For Richard

And

for Dan and Rebecca

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The subject matter of physiology is the foundation of the practice of medicine, and a

firm grasp of its principles is essential for the physician. This book is intended to aid

the student preparing for the United States Medical Licensing Examination (USMLE)

Step 1. It is a concise review of key physiologic principles and is intended to help the

student recall material taught during the first and second years of medical school. It is

not intended to substitute for comprehensive textbooks or for course syllabi, although

the student may find it a useful adjunct to physiology and pathophysiology courses.

The material is organized by organ system into seven chapters. The first chapter

reviews general principles of cellular physiology. The remaining six chapters review

the major organ systems—neurophysiology, cardiovascular, respiratory, renal and

acid–base, gastrointestinal, and endocrine physiology.

Difficult concepts are explained stepwise, concisely, and clearly, with appropriate

illustrative examples and sample problems. Numerous clinical correlations are

included so that the student can understand physiology in relation to medicine. An

integrative approach is used, when possible, to demonstrate how the organ systems

work together to maintain homeostasis. More than 130 full-color illustrations and

flow diagrams and more than 50 tables help the student visualize the material quickly

and aid in long-term retention. The inside front cover contains “Key Physiology Topics

for USMLE Step 1.” The inside back cover contains “Key Physiology Equations for

USMLE Step 1.”

Questions reflecting the content and format of USMLE Step 1 are included at the

end of each chapter and in a Comprehensive Examination at the end of the book.

These questions, many with clinical relevance, require problem-solving skills rather

than straight recall. Clear, concise explanations accompany the questions and guide

the student through the correct steps of reasoning. The questions can be used as a

pretest to identify areas of weakness or as a post test to determine mastery. Special

attention should be given to the Comprehensive Examination, because its questions

integrate several areas of physiology and related concepts of pathophysiology and

pharmacology.

New to this edition:

■ Addition of new full-color figures

■ Updated organization and text

■ Expanded coverage of cellular, respiratory, renal, gastrointestinal, and

endocrine physiology

■ Increased emphasis on pathophysiology

Best of luck in your preparation for USMLE Step 1!

Linda S. Costanzo, Ph.D.

Chapter 3 vii

Preface

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Acknowledgments

ix

It has been a pleasure to be a part of the Board Review Series and to work with the staff

at Lippincott Williams & Wilkins. Crystal Taylor and Stacey Sebring provided expert edi￾torial assistance. Matthew Chansky again served as illustrator, revising and colorizing

existing figures and creating new ones.

My sincere thanks to students in the School of Medicine at Virginia Commonwealth

University/Medical College of Virginia, who have provided so many helpful suggestions

for BRS Physiology. Thanks also to the many students from other medical schools who

have taken the time to write to me about their experiences with this book.

Linda S. Costanzo, Ph.D.

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Preface vii

Acknowledgments ix

1. CELL PHYSIOLOGY 1

I. Cell Membranes 1

II. Transport Across Cell Membranes 2

III. Osmosis 5

IV. Diffusion Potential, Resting Membrane Potential,

and Action Potential 7

V. Neuromuscular and Synaptic Transmission 12

VI. Skeletal Muscle 16

VII. Smooth Muscle 20

VIII. Comparison of Skeletal Muscle, Smooth Muscle,

and Cardiac Muscle 22

Review Test 23

2. NEUROPHYSIOLOGY 31

I. Autonomic Nervous System 31

II. Sensory Systems 35

III. Motor Systems 47

IV. Higher Functions of the Cerebral Cortex 53

V. Blood–Brain Barrier and Cerebrospinal Fluid 54

VI. Temperature Regulation 55

Review Test 57

3. CARDIOVASCULAR PHYSIOLOGY 64

I. Circuitry of the Cardiovascular System 64

II. Hemodynamics 64

III. Cardiac Electrophysiology 69

IV. Cardiac Muscle and Cardiac Output 74

Chapter xi

Contents

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xii Contents

V. Cardiac Cycle 83

VI. Regulation of Arterial Pressure 85

VII. Microcirculation and Lymph 89

VIII. Special Circulations 92

IX. Integrative Functions of the Cardiovascular System: Gravity, Exercise,

and Hemorrhage 95

Review Test 100

4. RESPIRATORY PHYSIOLOGY 113

I. Lung Volumes and Capacities 113

II. Mechanics of Breathing 115

III. Gas Exchange 122

IV. Oxygen Transport 123

V. CO2 Transport 128

VI. Pulmonary Circulation 129

VII. V/Q Defects 131

VIII. Control of Breathing 132

IX. Integrated Responses of the Respiratory System 134

Review Test 136

5. RENAL AND ACID–BASE PHYSIOLOGY 144

I. Body Fluids 144

II. Renal Clearance, Renal Blood Flow, and Glomerular Filtration Rate 148

III. Reabsorption and Secretion 152

IV. NaCl Regulation 155

V. K Regulation 159

VI. Renal Regulation of Urea, Phosphate, Calcium, and Magnesium 162

VII. Concentration and Dilution of Urine 163

VIII. Renal Hormones 168

IX. Acid–Base Balance 168

X. Diuretics 177

XI. Integrative Examples 177

Review Test 180

6. GASTROINTESTINAL PHYSIOLOGY 190

I. Structure and Innervation of the Gastrointestinal Tract 190

II. Regulatory Substances in the Gastrointestinal Tract 191

III. Gastrointestinal Motility 195

IV. Gastrointestinal Secretion 199

V. Digestion and Absorption 209

VI. Liver Physiology 214

Review Test 216

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Contents xiii

7. ENDOCRINE PHYSIOLOGY 222

I. Overview of Hormones 222

II. Cell Mechanisms and Second Messengers 224

III. Pituitary Gland (Hypophysis) 227

IV. Thyroid Gland 232

V. Adrenal Cortex and Adrenal Medulla 235

VI. Endocrine Pancreas—Glucagon and Insulin 242

VII. Calcium Metabolism (Parathyroid Hormone, Vitamin D,

Calcitonin) 245

VIII. Sexual Differentiation 249

IX. Male Reproduction 250

X. Female Reproduction 253

Review Test 257

Comprehensive Examination 265

Index 287

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