Embryology

  1. Fourth to Eighth Week
    1. Overview of the Embryonic Period
      1. Critical Periods of Organogenesis
        1. Susceptibility to Teratogens
        2. Folding of the Embryo
          1. Head Fold
            1. Tail Fold
              1. Lateral Folds
                1. Formation of the Body Shape
                  1. Incorporation of the Yolk Sac
                  2. Derivatives of the Ectoderm
                    1. Surface Ectoderm
                      1. Epidermis
                        1. Hair
                          1. Nails
                            1. Glands
                              1. Lens of the Eye
                                1. Enamel of Teeth
                                2. Neuroectoderm
                                  1. Neural Tube
                                    1. Brain
                                      1. Spinal Cord
                                      2. Neural Crest
                                        1. Sensory Ganglia
                                          1. Autonomic Ganglia
                                            1. Schwann Cells
                                              1. Melanocytes
                                                1. Craniofacial Cartilage and Bone
                                            2. Derivatives of the Mesoderm
                                              1. Paraxial Mesoderm
                                                1. Axial Skeleton
                                                  1. Skeletal Muscles
                                                    1. Dermis of Skin
                                                    2. Intermediate Mesoderm
                                                      1. Kidneys
                                                        1. Gonads
                                                        2. Lateral Plate Mesoderm
                                                          1. Somatic Layer
                                                            1. Body Wall
                                                              1. Limbs
                                                              2. Splanchnic Layer
                                                                1. Heart
                                                                  1. Blood Vessels
                                                                    1. Smooth Muscle of Gut
                                                                    2. Formation of Body Cavities
                                                                  2. Derivatives of the Endoderm
                                                                    1. Primitive Gut Tube
                                                                      1. Foregut
                                                                        1. Pharynx
                                                                          1. Esophagus
                                                                            1. Stomach
                                                                              1. Proximal Duodenum
                                                                              2. Midgut
                                                                                1. Distal Duodenum
                                                                                  1. Jejunum
                                                                                    1. Ileum
                                                                                      1. Cecum
                                                                                        1. Appendix
                                                                                          1. Ascending Colon
                                                                                            1. Proximal Transverse Colon
                                                                                            2. Hindgut
                                                                                              1. Distal Transverse Colon
                                                                                                1. Descending Colon
                                                                                                  1. Sigmoid Colon
                                                                                                    1. Rectum
                                                                                                      1. Upper Anal Canal
                                                                                                    2. Pharyngeal Apparatus
                                                                                                      1. Pharyngeal Arches
                                                                                                        1. Cartilage
                                                                                                          1. Muscles
                                                                                                            1. Nerves
                                                                                                              1. Arteries
                                                                                                              2. Pharyngeal Pouches
                                                                                                                1. Pharyngeal Grooves
                                                                                                                  1. Pharyngeal Membranes
                                                                                                                2. Development of Major Organ Systems
                                                                                                                  1. Nervous System Development
                                                                                                                    1. Brain Vesicles
                                                                                                                      1. Forebrain
                                                                                                                        1. Midbrain
                                                                                                                          1. Hindbrain
                                                                                                                          2. Spinal Cord
                                                                                                                            1. Peripheral Nervous System
                                                                                                                            2. Cardiovascular System Development
                                                                                                                              1. Heart Looping
                                                                                                                                1. Heart Septation
                                                                                                                                  1. Formation of Heart Chambers
                                                                                                                                    1. Aortic Arches
                                                                                                                                      1. Vitelline Vessels
                                                                                                                                        1. Umbilical Vessels
                                                                                                                                          1. Fetal Circulation
                                                                                                                                          2. Musculoskeletal System Development
                                                                                                                                            1. Axial Skeleton
                                                                                                                                              1. Appendicular Skeleton
                                                                                                                                                1. Musculature
                                                                                                                                                2. Respiratory System Development
                                                                                                                                                  1. Larynx
                                                                                                                                                    1. Trachea
                                                                                                                                                      1. Bronchi
                                                                                                                                                        1. Lungs
                                                                                                                                                        2. Digestive System Development
                                                                                                                                                          1. Esophagus
                                                                                                                                                            1. Stomach
                                                                                                                                                              1. Intestines
                                                                                                                                                                1. Liver
                                                                                                                                                                  1. Gallbladder
                                                                                                                                                                    1. Pancreas
                                                                                                                                                                    2. Urogenital System Development
                                                                                                                                                                      1. Kidney Systems
                                                                                                                                                                        1. Pronephros
                                                                                                                                                                          1. Mesonephros
                                                                                                                                                                            1. Metanephros
                                                                                                                                                                            2. Gonads
                                                                                                                                                                              1. Testes
                                                                                                                                                                                1. Ovaries
                                                                                                                                                                                2. Genital Ducts
                                                                                                                                                                                  1. External Genitalia
                                                                                                                                                                                  2. Head and Neck Development
                                                                                                                                                                                    1. Face
                                                                                                                                                                                      1. Nose
                                                                                                                                                                                        1. Palate
                                                                                                                                                                                          1. Tongue
                                                                                                                                                                                            1. Thyroid Gland
                                                                                                                                                                                            2. Limb Development
                                                                                                                                                                                              1. Limb Buds
                                                                                                                                                                                                1. Apical Ectodermal Ridge
                                                                                                                                                                                                  1. Digital Rays
                                                                                                                                                                                                    1. Limb Rotation
                                                                                                                                                                                                    2. Integumentary System Development
                                                                                                                                                                                                      1. Epidermis
                                                                                                                                                                                                        1. Dermis
                                                                                                                                                                                                          1. Skin Appendages

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                                                                                                                                                                                                      5. Third Week of Development

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                                                                                                                                                                                                      7. The Fetal Period