ANATOMY & PHYSIOLOGY DEVELOPMENTAL BIOLOGY A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z                    HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site amniotic sac The fetus in vitro, showing amniotic sac Credit: University of Utah, Health Sciences Center The membranous bag that surrounds the fetus and fills with watery amniotic fluid as pregnancy advances. The amniotic sac is made up of two membranes, the inner amnion and the outer chorion. Related categories    • ANATOMY AND PHYSIOLOGY    • DEVELOPMENTAL BIOLOGY Source: British Medical Association Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP