So these two arteries essentially bring the oxygenated blood as well as the nutrients to the hypothalamus portion as well as to this portion the posterior pituitary portion of our gland. Now, the question is when exactly do we release our oxytocin and what effect does the oxytocin hormone have on our body? Well, basically oxytocin is released during childbirth in the female human and this basically causes the contraction of smooth muscles in our uterus and that basically helps move our child out of the body. And what the oxytocin also does post childbirth is it basically stimulates the secretion the ejection of our milk found in the glands in the breast. So basically, this is the function of oxytocin while this is the function of the antidiaretic hormone. Both of these hormones are not actually produced in the posterior pituitary gland.