|General Gross Description|
Spongy red tissue comprising the bulk of the placenta bounded by fetal surface (chorionic plate) and maternal surface (basal plate)
|General Microscopic Description|
Early in gestation villi are covered by a complete layer of syncytiotrophoblast overlying a complete layer of cytotrophoblast.
Trophoblast is keratin positive but serves as endothelium for intervillous space.
At term there is a single trophoblast layer with scattered knotted synctial trophoblast nuclei
Trophoblast rests on basement membrane
Interior of villus contains connective tissue, Hofbauer cells (macrophages) and fetal vasculature which proliferates and ramifies throughout gestation
By term, the terminal villi contain vasculosyncytial membranes in which the basement membrane of the fetal capillary apposes the basement membrane of the trophoblast
During gestation the terminal villi diminish in cross sectional area and have progressively larger cut surface composed of vascular profiles
Benirschke K, Kaufmann P. Pathology of the human placenta, 3rd ed. New York: Springer-Verlag, 1995, pp. 116-142.
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|Synopsis by: Melinda Sanders M.D. (T88220M00100)