Other extra-embryonic folds expand up over the embryo to form the amniotic folds. The amnion and chorion develop together as upwardly projecting amniotic folds, eventually closing over the dorsal ...

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 ...