CHORIOALLANTOIC MEMBRANE

chorioallantoic membrane: translation

(1) Protective membrane around the eggs of insects and fishes.

(2) Extraembryonic membrane surrounding the embryo of amniote vertebrates. The outer epithelial layer of the chorion is derived from the trophoblast, by the apposition of the allantois to the inner face of the chorion. The chorioallantoic membrane is highly vascularized, and is used experimentally as a site upon which to place pieces of tissue in order to test their invasive capacity.