A structure established between the uterine and foetal tissues for the exchange of oxygen, carbon dioxide, waste, nutrients and other materials is:

Explanation

The placenta is defined as temporary intimate mechanical and the physiological connection between foetus and maternal tissue for the nutrition, respiration and excretion of the foetus. Human placenta consists of chorion only. The placenta is fully formed by the end of the third month and maintains pregnancy. In the placenta, the foetal blood comes very close to the maternal blood and this permits the exchange of material between the two. Food, water, mineral salt, vitamins, hormone antibodies and oxygen pass from the maternal blood into the foetal blood, and foetal metabolic waste, such as carbon dioxide, and urea, also water and hormones, pass into the maternal blood.