Week 6
Key Events of Human Development during the sixth week (week 6) following fertilization or Clinical week 8 (LMP).
Event | ||
Pituitary Week 6 - connecting stalk between pouch and oral cavity degenerates
Parathyroid Week 6 - diverticulum elongate, hollow then solid, dorsal cell proliferation Thymus Week 6 - diverticulum elongate, hollow then solid, ventral cell proliferation Adrenal Week 6 - fetal cortex forms from mesothelium adjacent to dorsal mesentery, medulla neural crest cells from adjacent sympathetic ganglia Respire Week 6 - descent of heart and lungs into thorax. Pleuroperitoneal foramen closes Tongue Week 6 - descent of heart and lungs into thorax. Pleuroperitoneal foramen closes gustatory papilla, caudal midline near the foramen caecum (week 6 to 7 - nerve fibers approach the lingual epithelium) | ||
Stage 16 | File:CST16.gifNeural first parasympathetic ganglia, submandibular and ciliary, are identifiable PMID: 2751117
Limbs upper limb bud nerves median nerve, radial nerve and ulnar nerve entered into hand plate, myoblasts spindle shaped and oriented parallel to limb bud axis. Heart outflow tract elliptical configuration with four cushions, the two larger fusing at this stage. Semilunar valve leaflets form at the downstream end of the cushions Head lip and palate components of the upper lip, medial nasal prominence and maxillary process present, median palatine process appears. | |
Stage 17 | File:CST17.gif
Neural telencephalon areas of the future archicortex, paleocortex, and neocortex, visible. Beginning of future choroid plexus PMID: 2802187 Sense - Smell olfactory nerve fibres enter the brain PMID: 15604533 Neural primordium of the epidural space appears first on the ventral part of the vertebral canal and develops rostro-caudally PMID: 15478101 | |
Heart separation of common cardiac outflow (aortic arch and pulmonary aorta) |
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Cite this page: Hill, M.A. (2024, June 27) Embryology Week 6. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Week_6
- © Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G