And ACTH goes down to the adrenal gland and it causes the adrenal gland to produce the precursor molecule that then goes down into the placenta. And the placenta uses that precursor molecule to form even more estrogen. And the rising level of estrogen ultimately causes the contraction of the smooth muscle found inside the uterus and that eventually leads to the process of childbirth. So one of the functions of the placenta is to act as an endocrine gland and it basically produces these four different types of hormones. Now the second and probably the primary purpose and the primary function of placenta is to act in gas exchange and nutrient exchange. So the placenta provides nutrients and exchanges gas between the blood of the mother and the blood of the fetus.