|See also amnion the outer of two membranes that form a sac around the embryonic reptile, bird, or mammal: contributes to the placenta in mammals|
|[C16: from Greek khorion afterbirth]|
chorion cho·ri·on (kôr'ē-ŏn')
The outer membrane enclosing the embryo in reptiles, birds, and mammals. In placental mammals it contributes to the development of the placenta.
|chorion (kôr'ē-ŏn') Pronunciation Key
The outer membrane that encloses the embryo of a reptile, bird, or mammal. In mammals, the chorion contributes to the development of the placenta.