The amnion and chorion develop together as upwardly projecting amniotic folds, eventually closing over the dorsal surface of the embryo. Eventually the free edges of the folds fuse and completely ...

The fetal membranes consist of the chorion, amnion, yolk sac, and allantois. The chorion has three layers: cytotrophoblastic, chorionic connective tissue, and basement membrane. The chorion lies ...