Template:Week 6 Embryo Stages and Events table
Week 6 - Human Embryo Stages and Events (GA week 8) | ||
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Embryo Week: Week 1 | Week 2 | Week 3 | Week 4 | Week 5 | Week 6 | Week 7 | Week 8 | Week 9 | ||
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 - gustatory papilla, caudal midline near the foramen caecum (week 6 to 7 - nerve fibers approach the lingual epithelium) | ||
Stage 16 | Neural - first parasympathetic ganglia, submandibular and ciliary, are identifiable[1]
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 |
Neural - telencephalon areas of the future archicortex, paleocortex, and neocortex, visible. Beginning of future choroid plexus[2] Sense - Smell olfactory nerve fibres enter the brain[3] Neural - primordium of the epidural space appears first on the ventral part of the vertebral canal and develops rostro-caudally[4] Pancreas - rotation of the developing stomach moves ventral bud dorsally and fuses with the dorsal bud. | |
Heart - separation of common cardiac outflow (aortic arch and pulmonary aorta) | ||
Note - the day timing of stages is only approximate, system names link to first page of that specific system, and events are based upon the literature cited below. | ||
References |