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Book Details
Abstract
As the study of embryology continues to be integrated with a range of disciplines, Before We Are Born remains the ideal solution for students who need to quickly learn the basics. Fully updated by the world’s foremost embryologists, this medical reference book provides concise guidance on human embryology at every stage of development, utilizing rich illustrations and photographs designed to further explain content.
- Understand all of the latest advances in embryology , including normal and abnormal embryogenesis, causes of birth defects, and the role of genes in human development.
- See how discoveries in molecular biology have affected clinical practice, including the development of sophisticated new techniques such as recumbent DNA technology and stem cell manipulation.
- Prepare for the USMLE Step 1 with clinical case presentations, highlighted in special boxes, which demonstrate how embryology concepts relate to clinical practice.
- Quickly review just the embryology information you need to know, masterfully distilled from the popular book The Developing Human, written by the same author team.
- Understand the complex concepts inherent in embryology with help from streamlined content, didactic illustrations, and clinical photos.
- Test your knowledge with brand-new review questions at the end of each chapter.
Table of Contents
Section Title | Page | Action | Price |
---|---|---|---|
Front Cover | cover | ||
Inside Front Cover | ifc1 | ||
Half title page | i | ||
Award page | ii | ||
Before We Are Born 9E | iii | ||
Copyright Page | iv | ||
Dedication | v | ||
Contributors | vii | ||
Preface | xi | ||
Acknowledgments | xiii | ||
Table Of Contents | xv | ||
1 Introduction to Human Development | 1 | ||
Importance of and Advances in Embryology | 1 | ||
Descriptive Terms | 2 | ||
Clinically Oriented Questions | 5 | ||
2 Human Reproduction | 7 | ||
Reproductive Organs | 7 | ||
Female Reproductive Organs | 7 | ||
Vagina | 7 | ||
Uterus | 7 | ||
Uterine Tubes | 10 | ||
Ovaries | 10 | ||
Female External Sex Organs | 10 | ||
Male Reproductive Organs | 10 | ||
Gametogenesis | 10 | ||
Meiosis | 10 | ||
Spermatogenesis | 11 | ||
Oogenesis | 14 | ||
Comparison of Male and Female Gametes | 14 | ||
Female Reproductive Cycles | 14 | ||
Ovarian Cycle | 14 | ||
Follicular Development | 14 | ||
Ovulation | 17 | ||
Corpus Luteum | 18 | ||
Menstrual Cycle | 18 | ||
Phases of Menstrual Cycle | 18 | ||
Menstrual Phase | 18 | ||
Proliferative Phase | 18 | ||
Luteal Phase | 18 | ||
Transportation of Gametes | 19 | ||
Oocyte Transport | 19 | ||
Sperm Transport | 19 | ||
Maturation of Sperms | 20 | ||
Viability of Oocytes and Sperms | 20 | ||
Clinically Oriented Questions | 20 | ||
3 First Week of Human Development | 21 | ||
Fertilization | 21 | ||
Phases of Fertilization | 21 | ||
Results of Fertilization | 23 | ||
Cleavage of Zygote | 23 | ||
Formation of Blastocyst | 23 | ||
Clinically Oriented Questions | 27 | ||
4 Second Week of Human Development | 29 | ||
Formation of Amniotic Cavity, Embryonic Disc, and Umbilical Vesicle | 30 | ||
Development of Chorionic Sac | 32 | ||
Implantation Sites of Blastocysts | 33 | ||
Clinically Oriented Questions | 34 | ||
5 Third Week of Human Development | 35 | ||
Gastrulation: Formation of Germ Layers | 35 | ||
Primitive Streak | 36 | ||
Notochordal Process and Notochord | 36 | ||
Allantois | 36 | ||
Neurulation: Formation of the Neural Tube | 38 | ||
Neural Plate and Neural Tube | 38 | ||
Neural Crest Formation | 39 | ||
Development of Somites | 39 | ||
Development of Intraembryonic Coelom | 40 | ||
Early Development of Cardiovascular System | 40 | ||
Vasculogenesis and Angiogenesis | 43 | ||
Development of Chorionic Villi | 45 | ||
Clinically Oriented Questions | 47 | ||
6 Fourth to Eighth Weeks of Human Development | 49 | ||
Folding of Embryo | 49 | ||
Head and Tail Folds | 51 | ||
Lateral Folds | 51 | ||
Germ Layer Derivatives | 51 | ||
Control of Embryonic Development | 51 | ||
Estimation of Embryonic Age | 54 | ||
Highlights of the Fourth to Eighth Weeks | 54 | ||
Fourth Week | 55 | ||
Fifth Week | 56 | ||
Sixth Week | 58 | ||
Seventh Week | 58 | ||
Eighth Week | 58 | ||
Clinically Oriented Questions | 61 | ||
7 Fetal Period: | 63 | ||
Highlights of Fetal Period | 64 | ||
Nine to Twelve Weeks | 64 | ||
Thirteen to Sixteen Weeks | 65 | ||
Seventeen to Twenty Weeks | 65 | ||
Twenty-One to Twenty-Five Weeks | 65 | ||
Twenty-Six to Twenty-Nine Weeks | 66 | ||
Thirty to Thirty-Eight Weeks | 67 | ||
Expected Date of Delivery | 67 | ||
Factors Influencing Fetal Growth | 67 | ||
Procedures for Assessing Fetal Status | 68 | ||
Ultrasonography | 68 | ||
Diagnostic Amniocentesis | 68 | ||
Chorionic Villus Sampling | 69 | ||
Cell Cultures | 69 | ||
Percutaneous Umbilical Cord Blood Sampling | 69 | ||
Magnetic Resonance Imaging | 69 | ||
Fetal Monitoring | 70 | ||
Alpha-Fetoprotein Assay | 70 | ||
Noninvasive Prenatal Diagnosis | 70 | ||
Neonatal Period | 70 | ||
Clinically Oriented Questions | 70 | ||
8 Placenta and Fetal Membranes | 71 | ||
Placenta | 71 | ||
Decidua | 72 | ||
Development of Placenta | 72 | ||
Fetomaternal Junction | 72 | ||
Intervillous Space | 72 | ||
Amniochorionic Membrane | 74 | ||
Placental Circulation | 74 | ||
Fetoplacental Circulation | 74 | ||
Maternal-Placental Circulation | 75 | ||
Placental Membrane | 76 | ||
Functions of Placenta | 77 | ||
Placental Metabolism | 77 | ||
Placental Transport | 77 | ||
Transfer of Gases. | 77 | ||
Nutritional Substances. | 78 | ||
Hormones. | 78 | ||
Electrolytes. | 78 | ||
Drugs and Drug Metabolites. | 78 | ||
Infectious Agents. | 79 | ||
Placental Protection by Maternal Antibodies | 79 | ||
Placental Excretion of Waste Products | 79 | ||
Placental Endocrine Synthesis and Secretion | 79 | ||
Uterine Growth During Pregnancy | 79 | ||
Parturition | 79 | ||
Stages of Labor | 79 | ||
Placenta and Fetal Membranes after Birth | 80 | ||
Variations in Placental Shape | 81 | ||
Maternal Surface of Placenta | 81 | ||
Fetal Surface of Placenta | 82 | ||
Umbilical Cord | 82 | ||
Amnion and Amniotic Fluid | 82 | ||
Significance of Amniotic Fluid | 84 | ||
Umbilical Vesicle | 84 | ||
Significance of Umbilical Vesicle | 84 | ||
Allantois | 84 | ||
Multiple Pregnancies | 85 | ||
Twins and Fetal Membranes | 85 | ||
Dizygotic Twins | 85 | ||
Monozygotic Twins | 85 | ||
Other Types of Multiple Births | 88 | ||
Clinically Oriented Questions | 89 | ||
9 Body Cavities, Mesenteries, and Diaphragm | 91 | ||
Embryonic Body Cavity | 91 | ||
Mesenteries | 92 | ||
Division of Embryonic Body Cavity | 92 | ||
Pleuropericardial Membranes | 92 | ||
Pleuroperitoneal Membranes | 93 | ||
Development of Diaphragm | 95 | ||
Septum Transversum | 95 | ||
Pleuroperitoneal Membranes | 95 | ||
Dorsal Mesentery of Esophagus | 95 | ||
Muscular Ingrowth from Lateral Body Walls | 96 | ||
Positional Changes and Innervation of the Diaphragm | 96 | ||
Clinically Oriented Questions | 99 | ||
10 Pharyngeal Apparatus, Face, and Neck | 101 | ||
Pharyngeal Arches | 101 | ||
Pharyngeal Arch Components | 102 | ||
Derivatives of Pharyngeal Arch Arteries | 104 | ||
Derivatives of Pharyngeal Arch Cartilages | 104 | ||
Derivatives of Pharyngeal Arch Muscles | 104 | ||
Derivatives of Pharyngeal Arch Nerves | 104 | ||
Pharyngeal Pouches | 106 | ||
Derivatives of Pharyngeal Pouches | 106 | ||
Pharyngeal Grooves | 108 | ||
Pharyngeal Membranes | 110 | ||
Development of Thyroid Gland | 111 | ||
Development of Tongue | 111 | ||
Lingual Papillae and Taste Buds | 114 | ||
Nerve Supply of Tongue | 114 | ||
Development of Salivary Glands | 115 | ||
Development of Face | 115 | ||
Development of Nasal Cavities | 119 | ||
Paranasal Sinuses | 120 | ||
Development of Palate | 121 | ||
Primary Palate | 121 | ||
Secondary Palate | 121 | ||
Clinically Oriented Questions | 126 | ||
11 Respiratory System | 127 | ||
Development of Larynx | 129 | ||
Development of Trachea | 129 | ||
Development of Bronchi and Lungs | 130 | ||
Maturation of Lungs | 133 | ||
Pseudoglandular Period (5–17 Weeks) | 133 | ||
Canalicular Period (16–25 Weeks) | 133 | ||
Terminal Saccular Period (24 Weeks to Late Fetal Period) | 134 | ||
Alveolar Period (Late Fetal Period to 8 Years) | 134 | ||
Clinically Oriented Questions | 135 | ||
12 Alimentary System | 137 | ||
Foregut | 137 | ||
Development of Esophagus | 138 | ||
Development of Stomach | 138 | ||
Rotation of Stomach | 138 | ||
Mesenteries of Stomach | 141 | ||
Omental Bursa | 141 | ||
Development of Duodenum | 141 | ||
Development of Liver and Biliary Apparatus | 141 | ||
Ventral Mesentery | 143 | ||
Development of Pancreas | 143 | ||
Development of Spleen | 143 | ||
Midgut | 144 | ||
Rotation of Midgut Loop | 145 | ||
Retraction of Intestinal Loops | 145 | ||
Fixation of Intestines | 145 | ||
Cecum and Appendix | 145 | ||
Hindgut | 153 | ||
Cloaca | 153 | ||
Partitioning of Cloaca | 153 | ||
Anal Canal | 155 | ||
Clinically Oriented Questions | 160 | ||
13 Urogenital System | 161 | ||
Development of Urinary System | 161 | ||
Development of Kidneys and Ureters | 161 | ||
Pronephroi | 162 | ||
Mesonephroi | 162 | ||
Metanephroi | 162 | ||
Positional Changes of Kidneys | 165 | ||
Changes in Blood Supply of Kidneys | 166 | ||
Development of Urinary Bladder | 170 | ||
Development of Urethra | 172 | ||
Development of Suprarenal Glands | 172 | ||
Development of Genital System | 174 | ||
Development of Gonads | 174 | ||
Indifferent Gonads | 174 | ||
Primordial Germ Cells | 175 | ||
Sex Determination | 175 | ||
Development of Testes | 175 | ||
Development of Ovaries | 176 | ||
Development of Genital Ducts | 179 | ||
Development of Male Genital Ducts and Glands | 179 | ||
Seminal Glands. | 179 | ||
Prostate. | 179 | ||
Bulbourethral Glands. | 179 | ||
Development of Female Genital Ducts and Glands | 179 | ||
Development of Vagina. | 180 | ||
Female Auxiliary Genital Glands. | 180 | ||
Development of External Genitalia | 180 | ||
Development of Male External Genitalia | 181 | ||
Development of Female External Genitalia | 181 | ||
Development of Inguinal Canals | 184 | ||
Relocation of Testes and Ovaries | 187 | ||
Descent of Testes | 187 | ||
Descent of Ovaries | 187 | ||
Clinically Oriented Questions | 188 | ||
14 Cardiovascular System | 189 | ||
Early Development of Heart and Blood Vessels | 190 | ||
Development of Veins Associated with Embryonic Heart | 190 | ||
Pharyngeal Arch Arteries and Other Branches of the Dorsal Aorta | 193 | ||
Intersegmental Arteries | 193 | ||
Fate of Vitelline and Umbilical Arteries | 193 | ||
Later Development of Heart | 193 | ||
Circulation through Primordial Heart | 197 | ||
Partitioning of Primordial Heart | 197 | ||
Partitioning of Primordial Atrium | 199 | ||
Changes in Sinus Venosus | 199 | ||
Primordial Pulmonary Vein and Formation of Left Atrium | 199 | ||
Partitioning of Primordial Ventricle | 199 | ||
Partitioning of Bulbus Cordis and Truncus Arteriosus | 201 | ||
Development of Cardiac Valves | 203 | ||
Conducting System of Heart | 203 | ||
Birth Defects of Heart and Great Vessels | 204 | ||
Derivatives of Pharyngeal Arch Arteries | 213 | ||
Derivatives of First Pair of Pharyngeal Arch Arteries | 214 | ||
Derivatives of Second Pair of Pharyngeal Arch Arteries | 214 | ||
Derivatives of Third Pair of Pharyngeal Arch Arteries | 214 | ||
Derivatives of Fourth Pair of Pharyngeal Arch Arteries | 214 | ||
Fate of Fifth Pair of Pharyngeal Arch Arteries | 214 | ||
Derivatives of Sixth Pair of Pharyngeal Arch Arteries | 214 | ||
Pharyngeal Arch Arterial Birth Defects | 216 | ||
Fetal and Neonatal Circulation | 216 | ||
Fetal Circulation | 219 | ||
Transitional Neonatal Circulation | 221 | ||
Derivatives of Fetal Vessels and Structures | 221 | ||
Umbilical Vein and Round Ligament of Liver | 221 | ||
Ductus Venosus and Ligamentum Venosum | 221 | ||
Umbilical Arteries and Abdominal Ligaments | 221 | ||
Oval Foramen and Oval Fossa | 221 | ||
Ductus Arteriosus and Ligamentum Arteriosum | 221 | ||
Development of the Lymphatic System | 222 | ||
Development of Lymph Nodes | 222 | ||
Development of Spleen and Tonsils | 223 | ||
Clinically Oriented Questions | 223 | ||
15 Musculoskeletal System | 225 | ||
Skeletal System | 225 | ||
Development of Cartilage and Bone | 227 | ||
Histogenesis of Cartilage | 227 | ||
Histogenesis of Bone | 227 | ||
Intramembranous Ossification | 227 | ||
Endochondral Ossification | 227 | ||
Development of Joints | 229 | ||
Fibrous Joints | 229 | ||
Cartilaginous Joints | 229 | ||
Synovial Joints | 229 | ||
Development of Axial Skeleton | 229 | ||
Development of Vertebral Column | 230 | ||
Cartilaginous Stage of Vertebral Development | 231 | ||
Bony Stage of Vertebral Development | 231 | ||
Development of Ribs | 232 | ||
Development of Sternum | 232 | ||
Development of Cranium | 232 | ||
Cartilaginous Neurocranium | 232 | ||
Membranous Neurocranium | 232 | ||
Cartilaginous Viscerocranium | 233 | ||
Membranous Viscerocranium | 233 | ||
Newborn Cranium | 234 | ||
Postnatal Growth of Cranium | 234 | ||
Development of Appendicular Skeleton | 236 | ||
Muscular System | 238 | ||
Development of Skeletal Muscle | 239 | ||
Myotomes | 240 | ||
Derivatives of Epaxial Divisions of Myotomes | 240 | ||
Derivatives of Hypaxial Divisions of Myotomes | 240 | ||
Pharyngeal Arch Muscles | 240 | ||
Ocular Muscles | 240 | ||
Tongue Muscles | 240 | ||
Limb Muscles | 241 | ||
Development of Smooth Muscle | 241 | ||
Development of Cardiac Muscle | 241 | ||
Development of Limbs | 241 | ||
Early Stages of Limb Development | 241 | ||
Final Stages of Limb Development | 243 | ||
Cutaneous Innervation of Limbs | 244 | ||
Blood Supply of Limbs | 244 | ||
Clinically Oriented Questions | 249 | ||
16 Nervous System | 251 | ||
Development of Nervous System | 251 | ||
Development of Spinal Cord | 254 | ||
Development of Spinal Ganglia | 256 | ||
Development of Spinal Meninges | 257 | ||
Positional Changes of Spinal Cord | 257 | ||
Myelination of Nerve Fibers | 257 | ||
Birth Defects of Spinal Cord | 257 | ||
Development of Brain | 259 | ||
Brain Flexures | 259 | ||
Hindbrain | 259 | ||
Myelencephalon | 260 | ||
Metencephalon | 261 | ||
Choroid Plexuses and Cerebrospinal Fluid | 263 | ||
Midbrain | 264 | ||
Forebrain | 264 | ||
Diencephalon | 265 | ||
Telencephalon | 267 | ||
Cerebral Commissures | 267 | ||
Congenital Anomalies of Brain | 268 | ||
Development of Peripheral Nervous System | 272 | ||
Spinal Nerves | 273 | ||
Cranial Nerves | 273 | ||
Somatic Efferent Cranial Nerves | 273 | ||
Nerves of Pharyngeal Arches | 273 | ||
Special Sensory Nerves | 274 | ||
Development of Autonomic Nervous System | 275 | ||
Sympathetic Nervous System | 275 | ||
Parasympathetic Nervous System | 275 | ||
Clinically Oriented Questions | 275 | ||
17 Development of Eyes and Ears | 277 | ||
Development of Eyes and Related Structures | 277 | ||
Development of Retina | 279 | ||
Development of Choroid and Sclera | 282 | ||
Development of Ciliary Body | 282 | ||
Development of Iris | 283 | ||
Development of Lens | 283 | ||
Development of Aqueous Chambers | 283 | ||
Development of Cornea | 284 | ||
Development of Eyelids | 284 | ||
Development of Lacrimal Glands | 284 | ||
Development of Ears | 284 | ||
Development of Internal Ears | 284 | ||
Development of Middle Ears | 285 | ||
Development of External Ears | 286 | ||
Clinically Oriented Questions | 289 | ||
18 Integumentary System | 291 | ||
Development of Skin and Appendages | 291 | ||
Epidermis | 291 | ||
Dermis | 292 | ||
Development of Glands | 293 | ||
Sebaceous Glands | 293 | ||
Sweat Glands | 294 | ||
Development of Hairs | 294 | ||
Development of Nails | 294 | ||
Development of Mammary Glands | 295 | ||
Development of Teeth | 296 | ||
Bud Stage of Tooth Development | 296 | ||
Cap Stage of Tooth Development | 297 | ||
Bell Stage of Tooth Development | 297 | ||
Tooth Eruption | 299 | ||
Clinically Oriented Questions | 301 | ||
19 Human Birth Defects | 303 | ||
Teratology: Study of Abnormal Development | 303 | ||
Birth Defects Caused by Genetic Factors* | 304 | ||
Numerical Chromosomal Abnormalities | 304 | ||
Trisomy | 306 | ||
Structural Chromosomal Abnormalities | 308 | ||
Translocation | 309 | ||
Deletion | 309 | ||
Birth Defects Caused by Mutant Genes | 310 | ||
Birth Defects Caused by Environmental Factors | 311 | ||
Principles of Teratogenesis | 311 | ||
Critical Periods of Human Development | 312 | ||
Human Teratogens | 314 | ||
Cigarette Smoking | 314 | ||
Alcohol | 314 | ||
Androgens and Progestogens | 314 | ||
Antibiotics | 315 | ||
Anticoagulants | 315 | ||
Anticonvulsants | 315 | ||
Antineoplastic Agents | 315 | ||
Angiotensin-Converting Enzyme Inhibitors | 315 | ||
Retinoic Acid (Vitamin A) | 315 | ||
Salicylates | 315 | ||
Acetaminophen | 316 | ||
Thyroid Drugs | 316 | ||
Tranquilizers | 316 | ||
Psychotropic Drugs | 316 | ||
Illicit Drugs | 316 | ||
Environmental Chemicals as Teratogens | 317 | ||
Organic Mercury | 317 | ||
Lead | 317 | ||
Polychlorinated Biphenyls | 317 | ||
Infectious Agents as Teratogens | 317 | ||
Rubella (German Measles) | 317 | ||
Cytomegalovirus | 317 | ||
Herpes Simplex Virus | 317 | ||
Varicella (Chickenpox) | 317 | ||
Human Immunodeficiency Virus | 318 | ||
Toxoplasmosis | 318 | ||
Congenital Syphilis | 318 | ||
Radiation as a Teratogen | 318 | ||
Maternal Factors as Teratogens | 318 | ||
Mechanical Factors as Teratogens | 319 | ||
Birth Defects Caused by Multifactorial Inheritance | 319 | ||
Clinically Oriented Questions | 319 | ||
20 The Cellular and Molecular Basis of Development | 321 | ||
Intercellular Communication | 322 | ||
Gap Junctions | 322 | ||
Cell Adhesion Molecules | 322 | ||
Morphogens | 323 | ||
Retinoic Acid | 323 | ||
Transforming Growth Factor-β/ Bone Morphogenetic Protein | 323 | ||
Sonic Hedgehog | 323 | ||
Wnt/β-Catenin Pathway | 325 | ||
Receptor Tyrosine Kinases | 325 | ||
Common Features | 325 | ||
Regulation of Angiogenesis by Receptor Tyrosine Kinases | 326 | ||
Notch-Delta Pathway | 326 | ||
Transcription Factors | 326 | ||
Hox/Homeobox Proteins | 327 | ||
Pax Genes | 327 | ||
Basic Helix-Loop-Helix Transcription Factors | 328 | ||
Epigenetics | 328 | ||
DNA Methylation | 328 | ||
Histone Modifications | 328 | ||
Acetylation | 328 | ||
Methylation | 329 | ||
Stem Cells: Differentiation Versus Pluripotency | 329 | ||
Summary of Common Signaling Pathways Used during Development | 329 | ||
Bibliography and Suggested Reading | 331 | ||
Chapter 1 | 331 | ||
Chapter 2 | 331 | ||
Chapter 3 | 331 | ||
Chapter 4 | 331 | ||
Chapter 5 | 331 | ||
Chapter 6 | 331 | ||
Chapter 7 | 332 | ||
Chapter 8 | 332 | ||
Chapter 9 | 332 | ||
Chapter 10 | 332 | ||
Chapter 11 | 332 | ||
Chapter 12 | 332 | ||
Chapter 13 | 333 | ||
Chapter 14 | 333 | ||
Chapter 15 | 333 | ||
Chapter 16 | 333 | ||
Chapter 17 | 334 | ||
Chapter 18 | 334 | ||
Chapter 19 | 334 | ||
Chapter 20 | 334 | ||
Answers to Clinically Oriented Questions | 337 | ||
Chapter 1 | 337 | ||
Chapter 2 | 337 | ||
Chapter 3 | 337 | ||
Chapter 4 | 338 | ||
Chapter 5 | 338 | ||
Chapter 6 | 338 | ||
Chapter 7 | 339 | ||
Chapter 8 | 339 | ||
Chapter 9 | 340 | ||
Chapter 10 | 340 | ||
Chapter 11 | 340 | ||
Chapter 12 | 340 | ||
Chapter 13 | 341 | ||
Chapter 14 | 341 | ||
Chapter 15 | 342 | ||
Chapter 16 | 343 | ||
Chapter 17 | 344 | ||
Chapter 18 | 344 | ||
Chapter 19 | 345 | ||
Index | 347 | ||
A | 347 | ||
B | 348 | ||
C | 348 | ||
D | 350 | ||
E | 350 | ||
F | 351 | ||
G | 352 | ||
H | 352 | ||
I | 353 | ||
J | 353 | ||
K | 353 | ||
L | 354 | ||
M | 354 | ||
N | 355 | ||
O | 356 | ||
P | 356 | ||
Q | 358 | ||
R | 358 | ||
S | 358 | ||
T | 359 | ||
U | 360 | ||
V | 360 | ||
W | 361 | ||
X | 361 | ||
Z | 361 | ||
Inside Back Cover | ibc1 |