Embryogenesis Flashcards
Cortical Reaction
- Cortical granules fuse with oolemma
- Granules release contents (enzymes) between oolemma and zona pellucida
The prechordal plate is also known as:
Buccopharyngeal membrane
-site of future mouth development
How does the prechordal plate form?
Small, disk-like thickening of hypoblast forms at the end of hte bilaminar embryonic disk
What is the result of gastrulation?
Trilaminar empbryo whose 3 layers are the embryonic endoderm, mesodem, and ectoderm. All layers derive from the epiblast cells.
When does the definitive yolk sac form?
When the endodermal cells divide and migrate around the yolk sac, they gradually replace the original hypoblast cells.
What does the notochord induce?
Neural plate, neural groove formation in the overlying ectoderm
Mesoderm’s three main regions?
paraxial, intermediate, lateral.
What does lateral plate split into?
Visceral and parietal layers
Definite yolk sac becomes?
Primitive gut tube
Histogenesis
Cell movement from undifferentiated to producing many different layers of tissue
Spina bifida
Epidermis does not form completely
Derivatives of Ectoderm
Dorsal root ganglion Sympathetic ganglia Peripheral nerves Schwann and satellite cells Adrenal medulla melanocytes
Derivatives of Mesoderm
Paraxial (somites-cartilage, bone, connective tissue of body and limbs)
Intermediate (Urogenital system)
Lateral Plate (Appendicular skeleton, tendons, ligaments, connective tissue of viscera and body wall)
Remnant of notochord
Nucleas polposus
(Paraxial) Somites Differentiation
Sclertotome- Cells migrate medially around notochord to form vertebral column
Dermatome: Cells migrate under ectoderm (epidermis) to form the dermis
Myotome: Cells divide into two groups, epaxial and hypaxial and form most skeletal muscles of the body
Long List– Derivatives of Ectoderm
Central Nervous System
- Neurons of Brain and Spinal Cord
- Glial cells of Brain and Spinal Cord
- ——-Astrocytes
- ——-Oligodendrocytes
- ——-Ependymal cells
Epidermis and Derivatives
-Keratinocytes of Skin, Hair, and Nails
Ameloblasts (enamel-forming cells) of developing teeth
Epithelial cells lining the oral cavity and anal canal
Salivary gland epithelium
Secretory cells of the pituitary adenohypophysis
-Acidophils: Somatotrophs (Growth hormone); Lactotrophs (mammotrophs, prolactin)
-Basophils: Corticotrophs (ACTH); Gonadotrophs (FSH, LH); Thyrotrophs (TSH)
-Chromophobes: Follicular cells, Depleted & developing secretory cells
Long List– Derivatives of Neural Crest
Peripheral Nervous System
- Neurons of the peripheral nervous system
- ——Ganglion cells
- Supporting cells of the peripheral nervous system
- ——Schwann cells & Satellite cells of ganglia
Adrenal medulla
-Chromaffin cells, Ganglion cells
Specialized cell populations of the epidermis
-Melanocytes, Merkel cells
Craniofacial (face & jaw) connective tissues
-All cells of developing teeth EXCEPT ameloblasts
——Odontoblasts , Cementoblasts, Pulp mesenchyme
Derivatives of craniofacial mesenchyme
——Craniofacial fibroblasts, osteoblasts, osteocytes, chondroblasts & chondrocytes
Long List– Derivatives of Endoderm
Epithelial cells lining the digestive tract, from esophagus to rectum
- Cells covering the intestinal surface: Enterocytes (absorptive cells), Goblet cells
- Cells lining the intestinal crypts: Enterocytes, Goblet cells Paneth cells
Digestive glands that arise from digestive tract lining
-Liver: Hepatocytes
-Pancreas: Pancreatic acinar cells, Pancreatic alpha cells (glucagon), Pancreatic beta cells (insulin), Pancreatic delta cells (somatostatin)
Lining of ducts leading to digestive glands
Lining of bile ducts, gall bladder & cystic duct
Lining of pancreatic ducts
-Epithelial cells lining the respiratory tract from trachea to alveoli
Respiratory epithelium (pseudostratified ciliated columnar) lining trachea, larynx, & bronchi
-Simple ciliated columnar and cuboidal lining bronchioles, terminal bronchioles, respiratory bronchioles, and alveolar ducts
-Clara cells
-Type I (squamous) alveolar cells
-Type II alveolar (septal) cells
Specialized cell populations of digestive and respiratory tracts & pancreatic islets
-APUD (amine precursor uptake and decarboxylation) or DNES (diffuse neuroendocrine system)
