(i) 1. Placenta—It helps irtIe nutrition, excretion and respiration of the embryo.
2. Chorion—It forms the placenta.
(ii) Amniotic fluid present in amniotic cavity, acts as shock absorber and prevents desiccation of embryo.
(iii) Umbilical cord makes the connection between placenta and foetus. It supplies the nutrients and 02 with maternal blood; to foetus and removes C02 and excretory wastes from foetus blood into maternal blood. Thus it acts as a transport channel between foetus and mother blood.
(iv) Placenta—Secrets HCG (Human Chorionic Gonadotropin) hormone.