Langman’s Medical Embryology
Langman’s Medical Embryology
Part 1 General Embryology 01
Chapter 1 Introduction to Molecular Regulation and Signaling 3
Gene Transcription 3 Other Regulators of Gene Expression 5 Induction and Organ Formation 5 Cell Signaling 6
Chapter 2 Gametogenesis Conversion of Germ Cells into Male and Female Gametes 10
Primordial Germ Cells 10 The Chromosome Theory of Inheritance 11 Morphological Changes During Maturation of the Gametes 21
Chapter 3 First Week of Development Ovulation to Implantation 29
Ovarian Cycle 29
Fertilization 32
Cleavage 37
Blastocyst Formation 37
Uterus at Time of Implantation 39
Chapter 4 Second Week of Development Bilaminar Germ Disc 43
Day 8 43 Day 9 43
Days 11 and 12 44 Day 13 46
Chapter 5 Third Week of Development Trilaminar Germ Disc 51
Gastrulation Formation of Embryonic Mesoderm and Endoderm 51 Formation of the Notochord 51 Establishment of the Body Axes 52 Fate Map Established During Gastrulation 57 Growth of the Embryonic Disc 57 Further Development of the Trophoblast 59
Chapter 6 Third to Eighth Weeks The Embryonic Period 63
Derivatives of the Ectodermal Germ Layer 63 Derivatives of the Mesodermal Germ Layer 70 Derivatives of the Endodermal Germ Layer 78 Patterning of the Anteroposterior Axis Regulation by Homeobox Genes 81
External Appearance During the Second Month 81
Chapter 7 The Gut Tube and the Body Cavities 86
A Tube on Top of a Tube 86 Formation of the Body Cavity 87 Serous Membranes 88 Diaphragm and Thoracic Cavity 90 Formation of the Diaphragm 92
Chapter 8 Third Month to Birth The Fetus and Placenta 96
Development of the Fetus 96
Fetal Membranes and Placenta 100
Chorion Frondosum and Decidua Basalis 102
Structure of the Placenta 103
Amnion and Umbilical Cord 107
Placental Changes at the End of Pregnancy 108
Amniotic Fluid 109
Fetal Membranes in Twins 110
Parturition Birth 115
Chapter 9 Birth Defects and Prenatal Diagnosis 1 1 7
Birth Defects 117 Prenatal Diagnosis 125 Fetal Therapy 128
Part 2 Systems-Based Embryology 131
Chapter 10 The Axial Skeleton 133
Skull 133
Vertebrae and the Vertebral Column 142 Ribs and Sternum 144
Chapter 11 Muscular System 145
Striated Skeletal Musculature 145
Innervation of Axial Skeletal Muscles 146
Skeletal Muscle and Tendons 148
Molecular Regulation of Muscle Development 148
Patterning of Muscles 148
Head Musculature 148
Limb Musculature 148
Cardiac Muscle 149
Smooth Muscle 149
Chapter 12 Limbs 151
Limb Growth And Development 151 Limb Musculature 152
Chapter 13 Cardiovascular System 162
Establishment and Patterning of the Primary Heart Field 162
Formation and Position of the Heart Tube 164 Formation of the Cardiac Loop 166 Molecular Regulation of Cardiac Development 169 Development of the Sinus Venosus 170 Formation of the Cardiac Septa 171 Formation of the Conducting System of the Heart 185
Vascular Development 185 Circulation Before and After Birth 195
Chapter 14 Respiratory System 201
Formation of the Lung Buds 201 Larynx 203
Trachea, Bronchi, And Lungs 203 Maturation of the Lungs 205
Chapter 15 Digestive System 208
Divisions of the Gut Tube 208 Molecular Regulation of Gut Tube Development 209 Mesenteries 210 Foregut 21 1
Molecular Regulation of Liver Induction 219 Pancreas 221 Midgut 222 Hindgut 229
Chapter 16 Urogenital System 232
Urinary System 232 Genital System 243
Chapter 17 Head and Neck 260
Pharyngeal Arches 262 Pharyngeal Pouches 266
Pharyngeal Clefts 268
Molecular Regulation of Facial Development 268 Tongue 273 Thyroid Gland 274 Face 275
Intermaxillary Segment 278 Secondary Palate 278 Nasal Cavities 282 Teeth 283
Molecular Regulation of Tooth Development 285
Chapter 18 Central Nervous System 287
Spinal Cord 288 Brain 297
Molecular Regulation of Brain Development 308 Cranial Nerves 313 Autonomic Nervous System 315
Chapter 19 Ear 321
Internal Ear 321 Middle Ear 324 External Ear 325
Chapter 20 Eye 329
Optic Cup and Lens Vesicle 329 Retina, Iris, and Ciliary Body 331 Lens 333
Choroid, Sclera, and Cornea 333 Vitreous Body 333 Optic Nerve 334
Molecular Regulation of Eye Development 334
Chapter 21 Integumentary System 339
Skin 339 Hair 341
Sweat Glands 342 Mammary Glands 342
Part 3 Appendix 345
Answers to Problems 347 Figure Credits 357 Glossary of Key Terms 361
Chapter 1 Introduction to Molecular Regulation and Signaling 3
Gene Transcription 3 Other Regulators of Gene Expression 5 Induction and Organ Formation 5 Cell Signaling 6
Chapter 2 Gametogenesis Conversion of Germ Cells into Male and Female Gametes 10
Primordial Germ Cells 10 The Chromosome Theory of Inheritance 11 Morphological Changes During Maturation of the Gametes 21
Chapter 3 First Week of Development Ovulation to Implantation 29
Ovarian Cycle 29
Fertilization 32
Cleavage 37
Blastocyst Formation 37
Uterus at Time of Implantation 39
Chapter 4 Second Week of Development Bilaminar Germ Disc 43
Day 8 43 Day 9 43
Days 11 and 12 44 Day 13 46
Chapter 5 Third Week of Development Trilaminar Germ Disc 51
Gastrulation Formation of Embryonic Mesoderm and Endoderm 51 Formation of the Notochord 51 Establishment of the Body Axes 52 Fate Map Established During Gastrulation 57 Growth of the Embryonic Disc 57 Further Development of the Trophoblast 59
Chapter 6 Third to Eighth Weeks The Embryonic Period 63
Derivatives of the Ectodermal Germ Layer 63 Derivatives of the Mesodermal Germ Layer 70 Derivatives of the Endodermal Germ Layer 78 Patterning of the Anteroposterior Axis Regulation by Homeobox Genes 81
External Appearance During the Second Month 81
Chapter 7 The Gut Tube and the Body Cavities 86
A Tube on Top of a Tube 86 Formation of the Body Cavity 87 Serous Membranes 88 Diaphragm and Thoracic Cavity 90 Formation of the Diaphragm 92
Chapter 8 Third Month to Birth The Fetus and Placenta 96
Development of the Fetus 96
Fetal Membranes and Placenta 100
Chorion Frondosum and Decidua Basalis 102
Structure of the Placenta 103
Amnion and Umbilical Cord 107
Placental Changes at the End of Pregnancy 108
Amniotic Fluid 109
Fetal Membranes in Twins 110
Parturition Birth 115
Chapter 9 Birth Defects and Prenatal Diagnosis 1 1 7
Birth Defects 117 Prenatal Diagnosis 125 Fetal Therapy 128
Part 2 Systems-Based Embryology 131
Chapter 10 The Axial Skeleton 133
Skull 133
Vertebrae and the Vertebral Column 142 Ribs and Sternum 144
Chapter 11 Muscular System 145
Striated Skeletal Musculature 145
Innervation of Axial Skeletal Muscles 146
Skeletal Muscle and Tendons 148
Molecular Regulation of Muscle Development 148
Patterning of Muscles 148
Head Musculature 148
Limb Musculature 148
Cardiac Muscle 149
Smooth Muscle 149
Chapter 12 Limbs 151
Limb Growth And Development 151 Limb Musculature 152
Chapter 13 Cardiovascular System 162
Establishment and Patterning of the Primary Heart Field 162
Formation and Position of the Heart Tube 164 Formation of the Cardiac Loop 166 Molecular Regulation of Cardiac Development 169 Development of the Sinus Venosus 170 Formation of the Cardiac Septa 171 Formation of the Conducting System of the Heart 185
Vascular Development 185 Circulation Before and After Birth 195
Chapter 14 Respiratory System 201
Formation of the Lung Buds 201 Larynx 203
Trachea, Bronchi, And Lungs 203 Maturation of the Lungs 205
Chapter 15 Digestive System 208
Divisions of the Gut Tube 208 Molecular Regulation of Gut Tube Development 209 Mesenteries 210 Foregut 21 1
Molecular Regulation of Liver Induction 219 Pancreas 221 Midgut 222 Hindgut 229
Chapter 16 Urogenital System 232
Urinary System 232 Genital System 243
Chapter 17 Head and Neck 260
Pharyngeal Arches 262 Pharyngeal Pouches 266
Pharyngeal Clefts 268
Molecular Regulation of Facial Development 268 Tongue 273 Thyroid Gland 274 Face 275
Intermaxillary Segment 278 Secondary Palate 278 Nasal Cavities 282 Teeth 283
Molecular Regulation of Tooth Development 285
Chapter 18 Central Nervous System 287
Spinal Cord 288 Brain 297
Molecular Regulation of Brain Development 308 Cranial Nerves 313 Autonomic Nervous System 315
Chapter 19 Ear 321
Internal Ear 321 Middle Ear 324 External Ear 325
Chapter 20 Eye 329
Optic Cup and Lens Vesicle 329 Retina, Iris, and Ciliary Body 331 Lens 333
Choroid, Sclera, and Cornea 333 Vitreous Body 333 Optic Nerve 334
Molecular Regulation of Eye Development 334
Chapter 21 Integumentary System 339
Skin 339 Hair 341
Sweat Glands 342 Mammary Glands 342
Part 3 Appendix 345
Answers to Problems 347 Figure Credits 357 Glossary of Key Terms 361