Basic-Sciences Review for Medical Licensure Developed at The University of Oklahoma, College of Medicine Suitable Reviews for: United States Medical Licensing Examination (USMLE), Step 1 Federation Licensing Examination (FLEX)
Embryology Second Edition Robert E. Coalson James J. Tomasek Springer-Verlag New York Berlin Heidelberg London Paris Tokyo Hong Kong Barcelona Budapest
Robert E. Coalson. Ph.D. James J. Tomasek. Ph.D. Department of Anatomical Sciences College of Medicine Health Sciences Center The University of Oklahoma Oklahoma City, OK 73190 USA Library of Congress Cataloging-in-Publication Data Coalson, Robert E. Embryology j Robert E. COalson, James J. Tomasek-2nd ed. p. cm.-(oklahoma notes) 1. Embryology, Human- Outlines, syllabi, ete. 2. Embryology, Human-Examinations, questions, etc. I. Tomasek, Jarnes J. II. Title. III. Series. [DNLM: 1. Embryology-examination questions. 2. Embryology-outlines. QS 18 C652ebJ QM601L64 1992 612.6'4' 0076-de20 DNLMjDLC for Library of Congress 92-2136 Printed on aeid-free paper. 1992, 1987 Springer-Verlag New York, lne. All rights reserved. This work may not be translated or eopied in whole or in part without the written permission of the publisher (Springer-Verlag New York, Ine., 175 Fifth Avenue, New York, NY 10010, USA), except for brief excerpts in conneetion with reviews or seholarly analysis. Use in connection with any form of information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed is forbidden.. The use of general deseriptive names, trade narnes, trademarks, ete., in this publication, even if the former are not espeeially identified, is not to be taken as a sign that such nam,es, as understood by the Trade Marks and Merehandise Marks Act, may aceordingly be used freely by anyone. While the adviee and information in this book is believed to be true and aceurate at the date of going to press, neither the authors nor the editors nor the publisher ean aeeept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respeet to tbe material eontained herein. Produetion managed by Henry Krell; manufacturing supervised by Jacqui Ashri. Carnera-ready copy prepared by the authors. 9 8 7 6 5 4 321 ISBN-13: 978-0-387-97776-8 DOI: 10.1007/978-1-4612-2900-1 e-isbn-13: 978-1-4612-2900-1
Preface to the ( ) ~ ~ In 1973, the University of Oklahoma College of Medicine instituted a requirement for passage of the Part 1 National Boards for promotion to the third year. To assist students in preparation for this examination, a two-week review of the basic sciences was added to the curriculum in 1975. Ten review texts were written by the faculty: four in anatomical sciences and one each in the other six basic sciences. Self-instructional quizzes were also developed by each discipline and administered during the review period. The first year the course was instituted the Total Score performance on National Boards Part I increased 60 points, with the relative standing of the school changing frorn 56th to 9th in the nation. The performance of the dass since then has remained near the national candidate mean (500) with a range of 467 to 537. This improvement in our own students' performance has been documented (Hyde et al: Performance on NBME Part I examination in relation to policies regarding use of test. J. Med. Educ. 60:439-443, 1985). A questionnaire was administered to one of the dasses after they had completed the Boards; 82% rated the review books as the most beneficial part of the course. These texts were subsequently rewritten and made available for use by all students of medicine who were preparing for comprehensive examinations in the Basic Medical Sciences. Since their introduction in 1987, over a quarter of a million copies have been sold. Assuming that 60,000 students have been first-time takers in the intervening five years, this equates to an average of four books per examinee. Obviously these texts have proven to be of value. The main reason is that they present a concise overview of each discipline, emphasizing the content and concepts most appropriate to the task at hand, Le., passage of a comprehensive examination over the Basic Medical Sciences. The recent changes in the licensure examination structure that have been made to create a Step l/step 2 process have necessitated a complete revision of the Oklahoma Notes. This task was begun in the summer of 1991; the book you are now holding is a product of that revision. Besides bringing each book up to date, the authors have made every effort to make the texts and review questions conform to the new format of the National Board of Medical Examiners tests. I hope you will find these review books valuable in your preparation for the licensure exams. Good Luck! Richard M. Hyde, Ph.D. Executive Editor
Preface This book was prepared to present an integrated review of selected topics in Human Embryology. It is designed specifically for students who completed standard courses in the various anatomical disciplines and who wish to review the developmental history of the major organ systems. This book will provide medical students with a highly suitable review for Step 1 of the United States Medical Licensing Exam (USMLE, Step 1). R. E. Coalson J. J. Tomasek
Acknowledgments We wish to acknowledge the invaluable assistance provided by our colleagues at the University of Oklahoma Health Sciences Center during preparation of this review. In particular, we would like to thank Ms. Nancy Halliday for proofreading, Mr. Shawn Schlinke for preparation of the illustrations, Mr. Melville Vaughan for assistance with mounting the illustrations, and Ms. Trenda Tanner for assistance with the typing.
Contents Preface to the Oklahoma Notes... Preface... Acknowledgments... v vii viii 1. Gametogenesis... 1 2. Female Reproductive Cycle... 9 3. Fertilization and Pregnancy... 12 4. Implantation and Formation of the Deciduae... 15 5. Formation of the Placenta... 18 6. Fetal Membranes and Umbilical Cord... 22 7. Early Development of the Conceptus 26 8. Development of General Body Form... 32 9. Nervous System......................... 35 10. Musculoskeletal System...:... 46 11. Integumentary System... 57 12. Oral Cavity and Development of the Branchial Apparatus... 62 13. Differentiation of the Branchial Apparatus... 66 14. Face and Palate... 72 15. Digestive System and Mesenteries... 78 16. Diaphragm and Body Cavities... 86 17. Respiratory System... 91 18. Urogenital System.,... 95 19. Cardiovascular System... 103 20. Fetal Circulation and Changes at Birth... 114