Template:Frog Cornea Timeline table: Difference between revisions
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Revision as of 11:51, 17 April 2018
Stage | Event |
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stage 25 | cornea starts from a simple embryonic epidermis overlying developing optic vesicle |
stage 30 | detachment of lens placode, cranial neural crest cells start to invade the space between the lens and the embryonic epidermis to construct the corneal endothelium. |
stage 41 | second wave of migratory cells containing presumptive keratocytes invades the matrix, leading to formation of inner cornea and outer cornea. A unique cell mass (stroma attracting center) connects the two layers like the center pole of a tent. |
stage 48 | secondary stromal keratocytes individually migrate to the center and form the stroma layer. |
stage 60 | stroma space is filled by collagen lamellae and keratocytes, and the stroma attracting center disappears. At early metamorphosis, embryonic epithelium gradually changes to adult corneal epithelium, covered by microvilli. |
stage 62 | embryonic epithelium thickens and cell death is observed in the epithelium, coinciding with eyelid opening. |
After metamorphosis | cornea has attained the adult structure of three cellular layers, epithelium, stroma, and endothelium, and between the cellular layers lie two acellular layers (Bowman's layer and Descemet's membrane) |
frog | vision |