https://t.me/MedicalBooksStore Physiology SEVENTH EDITION Physiology SEVENTH EDITION Linda S. Costanzo, Ph.D. Professor of Physiology and Biophysics School of Medicine Virginia Commonwealth University Richmond, Virginia Acquisitions Editor: Crystal Taylor Development Editor: Andrea Vosburgh Editorial Coordinator: Tim Rinehart Marketing Manager: Michael McMahon Production Project Manager: Marian Bellus Design Coordinator: Holly McLaughlin Manufacturing Coordinator: Margie Orzech Prepress Vendor: SPi Global Seventh edition Copyright © 2019 Wolters Kluwer Copyright © 2015, 2011, 2007, 2003, 1998, 1995 Wolters Kluwer Health. All rights reserved. This book is protected by copyright. No part of this book may be reproduced or transmitted in any form or by any means, including as photocopies or scanned-in or other electronic copies, or utilized by any information storage and retrieval system without written permission from the copyright owner, except for brief quotations embodied in critical articles and reviews. Materials appearing in this book prepared by individuals as part of their official duties as U.S. government employees are not covered by the above-mentioned copyright. To request permission, please contact Wolters Kluwer at Two Commerce Square, 2001 Market Street, Philadelphia, PA 19103, via email at [email protected], or via our website at lww.com (products and services). 9 8 7 6 5 4 3 2 1 Printed in China Library of Congress Cataloging-in-Publication Data Names: Costanzo, Linda S., 1947- author. Title: Physiology / Linda S. Costanzo. Other titles: Board review series. Description: Seventh edition. | Philadelphia : Wolters Kluwer, [2019] | Series: BRS | Includes index. Identifiers: LCCN 2017054852 | ISBN 9781496367617 Subjects: | MESH: Physiological Phenomena | Examination Questions Classification: LCC QP40 | NLM QT 18.2 | DDC 612.0076—dc23 LC record available at https://lccn.loc.gov/2017054852 This work is provided “as is,” and the publisher disclaims any and all warranties, express or implied, including any warranties as to accuracy, comprehensiveness, or currency of the content of this work. This work is no substitute for individual patient assessment based upon healthcare professionals’ examination of each patient and consideration of, among other things, age, weight, gender, current or prior medical conditions, medication history, laboratory data and other factors unique to the patient. The publisher does not provide medical advice or guidance and this work is merely a reference tool. Healthcare professionals, and not the publisher, are solely responsible for the use of this work including all medical judgments and for any resulting diagnosis and treatments. Given continuous, rapid advances in medical science and health information, independent professional verification of medical diagnoses, indications, appropriate pharmaceutical selections and dosages, and treatment options should be made and healthcare professionals should consult a variety of sources. When prescribing medication, healthcare professionals are advised to consult the product information sheet (the manufacturer’s package insert) accompanying each drug to verify, among other things, conditions of use, warnings and side effects and identify any changes in dosage schedule or contraindications, particularly if the medication to be administered is new, infrequently used or has a narrow therapeutic range. To the maximum extent permitted under applicable law, no responsibility is assumed by the publisher for any injury and/or damage to persons or property, as a matter of products liability, negligence law or otherwise, or from any reference to or use by any person of this work. LWW.com For Richard And for Dan, Rebecca, and Sheila And for Elise and Max Preface 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. Appendices contain “Key Physiology Topics for USMLE Step 1,” “Key Physiology Equations for USMLE Step 1,” and “Normal Blood Values.” 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 posttest 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 neurophysiology, and respiratory, renal, gastrointestinal, and endocrine physiology Addition of new multi-step questions Best of luck in your preparation for USMLE Step 1! Linda S. Costanzo, Ph.D. Acknowledgments It has been a pleasure to be a part of the Board Review Series and to work with the staff at Wolters Kluwer. Crystal Taylor and Andrea Vosburgh provided expert editorial assistance. 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. Contents Preface Acknowledgments 1. CELL PHYSIOLOGY I. Cell Membranes II. Transport Across Cell Membranes III. Osmosis IV. Diffusion Potential, Resting Membrane Potential, and Action Potential V. Neuromuscular and Synaptic Transmission VI. Skeletal Muscle VII. Smooth Muscle VIII. Comparison of Skeletal Muscle, Smooth Muscle, and Cardiac Muscle Review Test 2. NEUROPHYSIOLOGY I. Autonomic Nervous System (ANS) II. Organization of the Nervous System III. Sensory Systems IV. Motor Systems V. Higher Functions of the Cerebral Cortex VI. Blood–Brain Barrier and Cerebrospinal Fluid (CSF) VII. Temperature Regulation Review Test 3. CARDIOVASCULAR PHYSIOLOGY I. Circuitry of the Cardiovascular System II. Hemodynamics III. Cardiac Electrophysiology IV. Cardiac Muscle and Cardiac Output V. Cardiac Cycle