The Developing Human E-Book , livre ebook

The Developing Human
Clinically Oriented Embryology
Ninth Edition

Keith L. Moore, MSc, PhD, FIAC, FRSM, FAAA
Professor Emeritus, Division of Anatomy, Department of Surgery Faculty of Medicine, University of Toronto
Former Professor and Head, Department of Anatomy, University of Manitoba, Winnipeg, Manitoba, Canada
Former Professor and Chair, Department of Anatomy and Cell Biology, University of Toronto, Toronto, Ontario, Canada

T.V.N. Persaud, MD, PhD, DSc, FRCPath (Lond.), FAAA
Professor Emeritus and Former Head, Department of Human Anatomy and Cell Science, Professor of Pediatrics and Child Health, Associate Professor of Obstetrics, Gynecology, and Reproductive Sciences, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
Professor of Anatomy and Embryology, St. George’s University, Grenada, West Indies

Mark G. Torchia, MSc, PhD
Associate Professor and Director of Development, Department of Surgery, Associate Professor, Department of Human Anatomy and Cell Sciences, Director, University Teaching Services, University of Manitoba, Winnipeg, Manitoba, Canada
Saunders
Award


Keith L. Moore
Recipient of the inaugural Henry Gray/Elsevier Distinguished Educator Award in 2007 —the American Association of Anatomists, highest award for excellence in human anatomy education at the medical/dental, graduate, and undergraduate levels of teaching; the Honored Member Award of the American Association of Clinical Anatomists (1994) for significant contributions to the field of clinically relevant anatomy; and the J.C.B. Grant Award of the Canadian Association of Anatomists (1984) “in recognition of meritorious service and outstanding scholarly accomplishments in the field of anatomical sciences.” In 2008 Professor Moore was inducted as a Fellow of the American Association of Anatomists . The rank of Fellow honors distinguished AAA members who have demonstrated excellence in science and in their overall contributions to the medical sciences.

T.V.N. (Vid) Persaud
Recipient of the Henry Gray/Elsevier Distinguished Educator Award in 2010 —the American Association of Anatomists’ highest award for excellence in human anatomy education at the medical/dental, graduate, and undergraduate levels of teaching; the Honored Member Award of the American Association of Clinical Anatomists (2008) for significant contributions to the field of clinically relevant anatomy; and the J.C.B. Grant Award of the Canadian Association of Anatomists (1991) “in recognition of meritorious service and outstanding scholarly accomplishments in the field of anatomical sciences.” In 2010 Professor Persaud was inducted as a Fellow of the American Association of Anatomists . The rank of Fellow honors distinguished AAA members who have demonstrated excellence in science and in their overall contributions to the medical sciences.
Front Matter

The Developing Human Clinically Oriented Embryology
9th Edition
Keith L. Moore,
MSc, PhD, FIAC, FRSM, FAAA
Professor Emeritus, Division of Anatomy, Department of Surgery
Faculty of Medicine, University of Toronto,
Former Professor and Head, Department of Anatomy, University of Manitoba, Winnipeg, Manitoba, Canada
Former Professor and Chair, Department of Anatomy and Cell Biology, University of Toronto, Toronto, Ontario, Canada
T.V.N. Persaud,
MD, PhD, DSc, FRCPath (Lond.), FAAA
Professor Emeritus and Former Head, Department of Human Anatomy and Cell Science
Professor of Pediatrics and Child Health
Associate Professor of Obstetrics, Gynecology, and Reproductive Sciences, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
Professor of Anatomy and Embryology, St. George’s University, Grenada, West Indies
Mark G. Torchia,
MSc, PhD
Associate Professor and Director of Development, Department of Surgery
Associate Professor, Department of Human Anatomy and Cell Sciences
Director, University Teaching Services, University of Manitoba
Winnipeg, Manitoba, Canada
Copyright

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THE DEVELOPING HUMAN: CLINICALLY ORIENTED EMBRYOLOGY, 9TH EDITION
ISBN: 978-1-4377-2002-0
Copyright © 2013 by Saunders, an imprint of Elsevier Inc.
No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions .
This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein).

Notices
Knowledge and best practice in this field are constantly changing. As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary.
Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility.
With respect to any drug or pharmaceutical products identified, readers are advised to check the most current information provided (i) on procedures featured or (ii) by the manufacturer of each product to be administered, to verify the recommended dose or formula, the method and duration of administration, and contraindications. It is the responsibility of practitioners, relying on their own experience and knowledge of their patients, to make diagnoses, to determine dosages and the best treatment for each individual patient, and to take all appropriate safety precautions.
To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors, assume any liability for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein.
Previous editions copyrighted 2008, 2003, 1998, 1993, 1988, 1982, 1977, 1973
Library of Congress Cataloging-in-Publication Data
Moore, Keith L.
The developing human: clinically oriented embryology / Keith L. Moore, T.V.N. Persaud, Mark G. Torchia. — 9th ed.
p. ; cm.
Includes bibliographical references and index.
ISBN 978-1-4377-2002-0 (pbk. : alk. paper) 1.  Embryology, Human. 2.  Abnormalities, Human. I.  Persaud, T. V. N. II.  Torchia, Mark G. III.  Title.
[DNLM: 1.  Embryology. QS 604]
QM601.M76 2013
612.6′4018—dc23
2011022743
Executive Content Strategist: Madelene Hyde
Content Development Specialist: Christine Abshire

Publishing Services Manager: Pat Joiner-Myers
Project Manager: Marlene Weeks
Designer: Steven Stave
Printed in Canada
Last digit is the print number: 9 8 7 6 5 4 3 2 1
Dedication
In Loving Memory of Marion
My best friend, wife, colleague, mother of our five children and grandmother of our nine grandchildren, for her love, unconditional support, and understanding. Wonderful memories keep you ever near our hearts.
— KLM and family
To Pam and Ron
I am grateful to my eldest daughter Pam, who assumed the office duties her mother previously carried out. She is also helpful in many other ways. 1 am also grateful to my son-in-law Ron Crowe, whose technical skills have helped me prepare the manuscript for this book.
— KLM
For Gisela
My lovely wife and best friend, for her endless support and patience; our three children—Indrani, Sunita, and Rainer (Ren)—and grandchildren (Brian, Amy, and Lucas)
— TVNP
For Barbara, Erik, and Muriel
You have never doubted my dreams and ideas, no matter how crazy they might be. Nothing could ever mean more to me than each of you. This book is also dedicated to my mentors, Drs. Rudy Danzinger, Gordon Grahame, and Jim Thliveris; thank you for sharing your knowledge and wisdom.
— MGT
For Our Students and Their Teachers
To our students: We hope you will enjoy reading this book, increase your understanding of human embryology, pass all of your exams, and be excited and well prepared for your careers in patient care, research, and teaching. You will remember some of what you hear; much of what you read; more of what you see, and almost all of what you experience and understand fully.
To their teachers: May this book be a helpful resource to you and your students.
We appreciate the numerous constructive comments we have received over the years from both students and teachers. Your remarks have been invaluable to us in improving this book. Kindly keep on sending your suggestions by e-mail to: persaud@cc.umanitoba.ca (Dr. Vid Persaud).
Contributors

David D. Eisenstat, MD, MA, FRCPC, Professor, Departments of Pediatrics and Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta; Director, Division of Pediatric Hemato