Flashcards in Repro - Embryology (Embryologic derivatives & Organ morphogenesis) Deck (20)
What are 3 major derivatives/aspects of ectoderm?
(1) Surface ectoderm (2) Neuroectoderm (3) Neural crest
What are 6 derivatives of surface ectoderm?
(1) Adenohypophysis (from Rathke pouch); (2) lens of eye; (3) epithelial linings of oral cavity, sensory organs of ear, and olfactory epithelium; (4) epidermis; (5) anal canal below the pectinate line; (6) parotid, sweat, and mammary glands
What is craniopharyngioma? What are its distinguish features? To what germ layer does it apply?
Benign Rathke pouch tumor with cholesterol crystals, calcifications; (Surface) Ectoderm
What are derivates of the neuroectoderm?
(1) Brain (neurohypophysis, CNS neurons, oligodendrocytes, astrocytes, ependymal cells, pineal gland), (2) retina and optic nerve, (3) spinal cord.
What system results from neuroectoderm?
Neuroectoderm - think CNS
What are 7 derivatives of the neural crest?
(1) PNS (dorsal root ganglion, cranial nerves, celiac ganglion, Schwann cells, ANS), (2) melanocytes, (3) chromaffin cells of adrenal medulla, (4) parafollicular (C) cells of thyroid, (5) pia and arachnoid, (6) bones of the skull, (7) odontoblasts, aorticopulmonary septum
From what germ layer does neural crest arise? What kinds of structures result from neural crest?
Neural crest - think PNS and non-neural structures nearby
What are 15 derivatives of mesoderm?
(1) Muscle, (2) bone, (3) connective tissue, (4) serous linings of body cavities (e.g., peritoneum), (5) spleen (derived from foregut mesentery), (6) cardiovascular structures, (7) lymphatics, (8) blood, (9) wall of gut tube, (10) vagina, (11) kidneys, (12) adrenal cortex, (13) dermis, (14) testes, (15) ovaries
What induces ectoderm to form neuroectoderm? What is another name for neuroectoderm?
Notochord induces ectoderm to form neuroectoderm (neural plate)
What is the only postnatal derivative of notochord? From which germ layer is notochord derived?
Its only postnatal derivative is the nucleus pulposus of the intervertebral disc; Mesoderm
What are mesodermal defects?
(1) Vertebral defects (2) Anal atresia (3) Cardiac defects (4) Tracheo-Esophageal fistula (5) Renal defects (6) Limb defects (bone and muscle); Think: "Mesodermal defects = VACTERL"
What are 3 derivatives of the endoderm?
(1) Gut tube epithelium (including anal canal above the pectinate line), (2) most of urethra (derived from urogenital sinus), (3) luminal epithelial derivatives (e.g., lungs, liver, gallbladder, pancreas, eustachian tube, thymus, parathyroid, thyroid follicular cells).
Name 7 types of errors in organ morphogenesis.
(1) Agenesis (2) Aplasia (3) Hypoplasia (4) Deformation (5) Disruption (6) Malformation (7) Sequence
What is agenesis, and what causes it?
Absent organ due to absent primordial tissue
What is aplasia?
Absent organ despite presence of primordial tissue
What is hypoplasia?
Incomplete organ development; primordial tissue present
What is deformation? When does it occur?
Extrinsic disruption; occurs after the embryonic period.
What is disruption? What is an example of this?
Secondary breakdown of a previously normal tissue or structure (e.g., amniotic band syndrome)
What is malformation? When does it occur?
Intrinsic disruption; occurs during the embryonic period (weeks 3-8)