Neurohypophysis (pars nervosa/posterior pituitary), stores, and releases oxytocin and vasopressin, that are actually synthesized by the hypothalamus and are transported axonally to the posterior pituitary. These axonal ends from the hypothalamus in posterior pituitary stores hormones and are called Herring bodies. Since posterior pituitary just stores and release hormone it is not considered as a true endocrine gland. Oxytocin stimulates smooth muscle contraction by acting on them. In females, it stimulates a vigorous contraction of the uterus at the time of childbirth, and milk ejection from the mammary gland. Vasopressin/ADH acts mainly to stimulate the resorption of water and electrolytes by the distal tubules and thereby reduces the loss of water through urine (diuresis).