So we see that the placenta, as a result of allowing the movement of immunoglobigging gives that growing embryo passive immunity because when the embryo grows the immune system of that embryo is not fully developed. So function number one is as an endocrine gland. Function number two is it provides a route by which there's an exchange between the nutrients such as glucose, water, minerals, so salts as well as amino acids between the blood of that mother and the blood of that fetus. Gas exchange also takes place. And that's important because as the fetus is developing the lungs of that fetus do not actually form until after birth takes place. And so the placenta acts as a system where gas exchange takes place.