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Carnegie Stage   Figure

Chorionic villus primordium

Chorionic villus primordium

A chorionic villus primordium from the embryonic pole of the ovum, arising by focal proliferation of cytotrophoblast and penetration of the latter into the more peripheral-lying, blood-containing syncytiotrophoblast. There is beginning formation in situ of mesoblasts and angioblasts (vacuolated cells, singly and in strands) within the base of the future villus and along the inner aspect of the nearby cytotrophoblast.

Fig. 30. Hertig and Rock, 1941.


Keywords: angioblasts, chorionic villi, cytotrophoblast, mesoblast, syncytiotrophoblast


Source: The Virtual Human Embryo.