Carlyle H. Chan, MD, FAPA Department of Psychiatry & Mental Health Science Medical College of Wisconsin Milwaukee, Wisconsin Appleton & Lange Reviews/McGraw-Hill Health Professions Division New York St. Louis San Francisco Auckland Bogotá Caracas Lisbon London Madrid Mexico City Milan Montreal New Delhi San Juan Singapore Sydney Tokyo Toronto APPLETON & LANGE’S R E V I E W third edition for the usmle step 2 Copyright © 2000 by The McGraw-Hill Companies. All rights reserved. Manufactured in the United States of America. Except as permitted under the United States Copyright Act of 1976, no part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written permission of the publisher. 0-07-138369-7 The material in this eBook also appears in the print version of this title: 0-8385-0341-1. All trademarks are trademarks of their respective owners. Rather than put a trademark symbol after every occurrence of a trademarked name, we use names in an editorial fashion only, and to the benefit of the trademark owner, with no intention of infringement of the trademark. Where such designa- tions appear in this book, they have been printed with initial caps. McGraw-Hill eBooks are available at special quantity discounts to use as premiums and sales promotions, or for use in corporate training programs. For more information, please contact George Hoare, Special Sales, at