FIRST AID ™ Q&A FOR THE USMLE STEP Second Edition SENIOR EDITORS EDITORS Tao Le, MD, MHS Karen A Adler, MD Assistant Clinical Professor Chief, Section of Allergy and Clinical Immunology Department of Medicine University of Louisville Resident Department of Psychiatry Massachusetts General Hospital Seth K Bechis, MS Yale School of Medicine Class of 2012 University of California, San Francisco Class of 2010 Jacob S Appelbaum Carina H.G Baird, MD Resident Department of Pediatrics University of California, San Francisco Xuemei Cai Harvard Medical School Class of 2009 Phillip J Gray, Jr Johns Hopkins University School of Medicine Class of 2009 Christopher R Kinsella, Jr Drexel University College of Medicine Class of 2009 Gabriel J Martinez-Diaz Stanford University School of Medicine Class 2010 New York / Chicago / San Francisco / Lisbon / London / Madrid / Mexico City Milan / New Delhi / San Juan / Seoul / Singapore / Sydney / Toronto Copyright © 2009 by Tao Le All rights reserved Except as 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prohibited Your right to use the work may be terminated if you fail to comply with these terms THE WORK IS PROVIDED “AS IS.” McGRAW-HILL AND ITS LICENSORS MAKE NO GUARANTEES OR WARRANTIES AS TO THE ACCURACY, ADEQUACY OR COMPLETENESS OF OR RESULTS TO BE OBTAINED FROM USING THE WORK, INCLUDING ANY INFORMATION THAT CAN BE ACCESSED THROUGH THE WORK VIA HYPERLINK OR OTHERWISE, AND EXPRESSLY DISCLAIM ANY WARRANTY, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE McGraw-Hill and its licensors not warrant or guarantee that the functions contained in the work will meet your requirements or that its operation will be uninterrupted or error free Neither McGraw-Hill nor its licensors shall be liable to you or anyone else for any inaccuracy, error or omission, regardless of cause, in the work or for any damages resulting therefrom McGrawHill has no responsibility for the content of any information accessed through the work Under no circumstances shall McGraw-Hill and/or its licensors be liable for any indirect, incidental, special, punitive, consequential or similar damages that result from the use of or inability to use the work, even if any of them has been advised of the possibility of such damages This limitation of liability shall apply to any claim or cause whatsoever whether such claim or cause arises in contract, tort or otherwise D E D I C AT I O N To the contributors to this and future editions, who took time to share their knowledge, insight, and humor for the benefit of students, residents, and clinicians and To our families, friends, and loved ones, who supported us in the task of assembling this guide This page intentionally left blank CONTENTS Authors vii Associate Authors ix Faculty Reviewers x Preface xiii Acknowledgments xv How to Contribute xvii S EC T IO N I G E N E RAL PRI NC I PLES Chapter Behavioral Science Chapter Biochemistry 17 Chapter Embryology 49 Chapter Microbiology 63 Chapter Immunology 91 Chapter Pathology 111 Chapter Pharmacology 127 S EC T IO N I I O R G A N SYST E M S 14 Chapter Cardiovascular 145 Chapter Endocrine 179 Chapter 10 Gastrointestinal 213 Chapter 11 Hematology-Oncology 247 Chapter 12 Musculoskeletal and Connective Tissue 279 Chapter 13 Neurology 309 Chapter 14 Psychiatry 331 Chapter 15 Renal 347 Chapter 16 Reproductive 381 Chapter 17 Respiratory 413 v S EC T IO N I I I F U LL-LE N G T H E X A M I NAT I O N S 445 Test Block 447 Test Block 481 Test Block 513 Test Block 547 Test Block 581 Test Block 613 Test Block 645 Appendix: Common Laboratory Values 675 About the Authors 681 vi AUTHORS REBECCA AHRENS SHARIFEH (SHERI) FARASAT Tri-Institutional MD/PhD Program Weill Medical College of Cornell University Johns Hopkins University School of Medicine Class of 2009 SARA ALCORN JAMES A FEINSTEIN, MD Harvard Medical School Class of 2010 Resident Department of Pediatrics Seattle Children's Hospital and Regional Medical Center VIJAY BABU, MD Intern Department of Internal Medicine The Reading Hospital Reading, Pa PAULA BORGES, MS Stanford University Medical School Class of 2009 RACHEL BORTNICK, MPhil Medical Scientist Training Program, Year V Harvard Medical School STEVEN CHEN Johns Hopkins University School of Medicine Class of 2010 JOHN CHILDRESS III University of Michigan Medical School Class of 2010 RAGHU CHIVUKULA Medical Scientist Training Program, Year IV Johns Hopkins University School of Medicine JUSTIN BRENT COHEN Yale School of Medicine Class of 2009 ANA COSTA, MD Resident Department of Anesthesiology Weill Medical College of Cornell University SHENNEN FLOY Harvard Medical School Class of 2009 ARIELLA FRIEDMAN Weill Medical College of Cornell University Class of 2008 ROBERT J GIANOTTI, MD Resident Department of Internal Medicine New York University PHILIP HALL Yale School of Medicine Class of 2010 DANIEL M HALPERIN Weill Medical College of Cornell University Class of 2009 COLLEEN M HARRISON Harvard Medical School Class of 2009 CHLOE HILL Weill Medical College of Cornell University Class of 2010 SELENA LIAO Harvard Medical School Class of 2009 ANDRES E CRUZ-INIGO KEN LIN Weill Medical College of Cornell University MARTIN H DOMINGUEZ Medical Scientist Training Program, Year V Harvard Medical School Class of 2010 MD/PhD Program Yale School of Medicine SUSAN MATHAI ALLEN OMID EGHRARI Yale School of Medicine Class of 2009 Johns Hopkins University School of Medicine Class of 2009 vii HEATHER MCGEE, MPhil TOMEKA L SUBER Medical Scientist Training Program, Year IV Yale School of Medicine Medical Scientist Training Program Johns Hopkins University School of Medicine LEAH MCNALLY CARLOS A TORRE Yale School of Medicine Class of 2009 University of Puerto Rico, Medical Science Campus Class of 2009 EMILY PFEIL JONATHAN TZU Johns Hopkins University School of Medicine Class of 2009 Johns Hopkins University School of Medicine Class of 2009 MICHELLE RIOS, MD BRANT W ULLERY, MD Resident Department of Internal Medicine University of California, Los Angeles Medical Center Resident Department of General Surgery Hospital of the University of Pennsylvania MAYA ROBERTS KELLY VRANAS, MD Yale School of Medicine and Harvard School of Public Health Class of 2009 Resident Department of Internal Medicine Hospital of the University of Pennsylvania MARIANELI RODRIGUEZ Medical Scientist Training Program Johns Hopkins University School of Medicine SEPIDEH SABER Stanford University School of Medicine Class of 2010 BENJAMIN SMITH Harvard Medical School Class of 2010 SARA STERN-NEZER Stanford University School of Medicine and University of California, Berkeley School of Public Health viiiviii FREDERICK WANG Yale School of Medicine Class of 2010 MARC WEIN Medical Scientist Training Program, Year VI Harvard Medical School RASIKA WICKRAMASINGHE, PhD Medical Scientist Training Program, Year VI Johns Hopkins University School of Medicine ASSOCIATE AUTHORS JAN BROWN II BENJAMIN SILVERBERG, MS St George’s University School of Medicine Class of 2010 University of Connecticut School of Medicine Class of 2009 PAUL D DI CAPUA HARRAS ZAID Yale School of Medicine Class of 2009 University of California, San Francisco School of Medicine Class of 2010 LARS GRIMM Yale School of Medicine Class of 2009 NICOLE M HSU Second Lieutenant, United States Air Force Medical Service Corps F Edward Hébert School of Medicine Uniformed Services University of the Health Sciences Class of 2009 ix