1. Between the foetus and mother there is exchange of several materials. Food in the form of glucose, amino acids, simple proteins, lipids, mineral, salts, vitamins and hormones, antibodies, etc. is sent to foetus by maternal circulation.
2. Oxygen from mother’s blood is also given to the foetus.
3. The foetal metabolic wastes such as carbon dioxide, urea and water pass from foetus into the maternal blood.
4. This exchange takes place through the placenta.
5. In the placenta, foetal blood comes very close to maternal blood to permit these exchanges. Therefore placenta is said to serve as the nutritive, respiratory and excretory organ of the embryo.
