The Nail Unit week 17
Partially keratinized sheet lies between nail bed and periderm
The early nail plate is derived from the dorsal and ventral epithelia of the matrix primordium, and the nail bed. Because the structure is only partially keratinized, it is brittle and breaks. As is grows distally, however, it displaces the keratinized cells of the dorsal ridge. The nail plate is completely covered by periderm.
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Self-Test A
Self-Test B
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