Table Of Content

Embryology at a Glance This title is also available as an e‐book. For more details, please see www.wiley.com/buy/9781118910801 or scan this QR code: Embryology at a Glance Second Edition Samuel Webster Senior Lecturer in Anatomy & Embryology Medical School Swansea University Swansea, UK Rhiannon de Wreede Honorary Lecturer College of Medicine Swansea University Swansea, UK This edition first published 2016 © 2016 by John Wiley & Sons, Ltd Previous edition © 2012 John Wiley & Sons, Ltd Registered Office John Wiley & Sons, Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK Editorial Offices 9600 Garsington Road, Oxford, OX4 2DQ, UK The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK 350 Main Street, Malden, MA 02148‐5020, USA For details of our global editorial offices, for customer services and for information about how to apply for permission to reuse the copyright material in this book please see our website at www.wiley.com/wiley‐blackwell The right of the authors to be identified as the authors of this work has been asserted in accordance with the UK Copyright, Designs and Patents Act 1988. 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Cover image: ©Steve Atherton Set in 9.5/11.5pt Minion by SPi Global, Pondicherry, India 1 2016 v Contents Preface vii Acknowledgements viii List of abbreviations ix Timeline x About the companion website xi Part 1 Early development 1 1 Embryology in medicine 2 2 Language of embryology 4 3 Introduction to development 6 4 Cell signalling genes 8 5 Embryonic and foetal periods 10 6 Mitosis 12 7 Meiosis 14 8 Spermatogenesis 16 9 Oogenesis 18 10 Fertilisation 20 11 From zygote to blastocyst 22 12 Implantation 24 13 Placenta 26 14 Gastrulation 28 15 Germ layers 30 16 Stem cells 32 17 Neurulation 34 18 Neural crest cells 36 19 Body cavities (embryonic) 38 20 Folding of the embryo 40 21 Segmentation 42 22 Somites 44 Part 2 Systems development 47 23 Skeletal system (ossification) 48 24 Skeletal system 50 25 Muscular system 52 26 Musculoskeletal system: limbs 54 27 Circulatory system: heart tube 56 28 Circulatory system: heart chambers 58 29 Circulatory system: blood vessels 60 30 Circulatory system: embryonic veins 62 31 Circulation system: changes at birth 64 32 Respiratory system 66 33 Digestive system: gastrointestinal tract 68 34 Digestive system: associated organs 70 35 Digestive system: congenital anomalies 72 36 Urinary system 74 vi 37 Reproductive system: ducts and genitalia 76 38 Reproductive system: gonads 78 39 Endocrine system 80 40 Head and neck: arch I 82 41 Head and neck: arch II 84 42 Head and neck: arch III 86 43 Head and neck: arches IV–VI 88 44 Central nervous system 90 45 Peripheral nervous system 92 46 The ear 94 47 The eye 96 48 Antenatal screening 98 Self-assessment MCQs 100 Self-assessment MCQ answers 104 Self-assessment EMQs 105 Self-assessment EMQ answers 107 Glossary 108 Index 112 vii Preface W e wrote this book for our students; those studying medicine with us, those listening to the podcasts wherever they may be, and those studying the other forms that biology takes on their paths to whatever goals they may have in life. We have introduced many students to the fascinating and often surprising processes of embryological development, and we hope to do the same in this book. It is written for anyone wondering, “where did I come from?” The content of this book extends beyond the curricula of most medicine, health and bioscience teaching programmes in terms of breadth, but we have limited its depth. Many embryology textbooks cover development in detail, but students struggle to get started, and to get to grips with early concepts. Hopefully we have addressed these difficulties with this book. We hope that you will use this book to begin your studies of embryology and development, but also that you will return to it when preparing for assessments or checking your understanding. You will find example assessment questions at the end of the book as well as a Glossary. Let this be the start of your integration of embryonic development with anatomy, to the ends of improved understanding and better patient care or scientific insight. Samuel Webster Rhiannon de Wreede viii Acknowledgements T hank you to Kim and Robin for being so encouraging and putting up with the time demands of completing this book. We would also like to thank the editors at Wiley‐Blackwell for leading us through this process and for their support and encouragement, and Jane Fallows for all her work with the illustrations. ix List of abbreviations AER Apical ectodermal ridge CAM Cell adhesion molecule CN Cranial nerve CSF Cerebrospinal fluid ECMO Extracorporeal membrane oxygenation FGF Fibroblast growth factor FSH Follicle stimulating hormone GnRH Gonadotrophin releasing hormone HbF Foetal haemoglobin hCG Human chorionic gonadotrophin hCS Human chorionic somatomammotrophin IUD Intrauterine device – contraceptive device IUGR Intrauterine growth restriction IVC Inferior vena cava IVD Intervertebral disc IVF In vitro fertilisation LH Luteinising hormone LMP Last menstrual period PDA Patent ductus arteriosus PFO Patent foramen ovale PTH Parathyroid hormone PZ Proliferating zone Rh Rhesus SVC Superior vena cava TGF Transforming growth factor ZPA Zone of polarising activity x Timeline Language of embryology (Chapter 2) Introduction to development (Chapter 3) Embryonic and foetal periods (Chapter 4) Spermatogenesis (Chapter 7) Oogenesis (Chapter 8) Fertilisation (Chapter 9) From zygote to blastocyst (Chapter 10) Implantation (Chapter 11) Placenta (Chapter 12) Gastrulation (Chapter 13) Formation of germ layers (Chapter 14) Formation of the heart tube (Chapter 25) Folding of the embryo (Chapter 18) Neurulation (Chapter 15) Segmentation (Chapter 19) Formation of blood vessels (Chapter 27) Somite development (Chapter 20) Development of digestive system (Chapter 31) Development of body cavities (Chapter 17) Development of urinary system (Chapter 34) Development of head and neck structures (Chapter 38–41) Development of the eye (Chapter 45) Migration of neural crest cells (Chapter 16) Development of muscular system (Chapter 23) Development of the ear (Chapter 44) Development of central nervous system (Chapter 42) Cranial neuropore closes (Chapter 15) Development of endocrine system (Chapter 36) Caudal neuropore closes (Chapter 15) Heart tube divides into four chambers (Chapter 26) Development of skeletal system (Chapter 22) Development of peripheral nervous system (Chapter 43) Development of musculoskeletal system (Chapter 24) Development of respiratory system (Chapter 30) Formation of the atrial septa (Chapter 26) Ossification of skeletal system (Chapter 21) Development of reproductive system (Chapter 35) Foetus can hear external sounds (Chapter 44) 0 10 20 30 Days Weeks 40 50 60 10 20 30 40 Death Menopause Days Weeks Adult Puberty Adult 0 10 20 30 40 50 60 10 20 30 40 Death Puberty Menopause xi About the companion website Don’t forget to visit the companion website for this book: www.ataglanceseries.com/embryology There you will find valuable material designed to enhance your learning, including: • Podcasts and animations hosted on Dr Webster’s website • An additional instructor resource comprising an image bank of all the figures from the book. Scan this QR code to visit the companion website 1 Early development Chapters 1 Embryology in medicine 2 2 Language of embryology 4 3 Introduction to development 6 4 Cell signalling genes 8 5 Embryonic and foetal periods 10 6 Mitosis 12 7 Meiosis 14 8 Spermatogenesis 16 9 Oogenesis 18 10 Fertilisation 20 11 From zygote to blastocyst 22 12 Implantation 24 13 Placenta 26 14 Gastrulation 28 15 Germ layers 30 16 Stem cells 32 17 Neurulation 34 18 Neural crest cells 36 19 Body cavities (embryonic) 38 20 Folding of the embryo 40 21 Segmentation 42 22 Somites 44 Part 1