Video - Development of the fetal membranes

The fetal membranes, also known as extraembryonic membranes, are associated with the developing embryo or fetus and protect and nourish it during gestation. These include the amnion, the yolk sac, the chorion, and the allantois. The chorion and amnion form the amniotic sac, which is filled with amniotic fluid in which the fetus is bathed in, safe from mechanical shock, and the allantois, which collects waste products from the embryo. The allantois degenerates early in pregnancy.