TJ. The hypothalamus is a brain structure made up of distinct nuclei as well as less anatomically distinct areas. It is found in all vertebrate nervous systems. In mammals, magnocellular neurosecretory cells in the paraventricular nucleus and the supraoptic nucleus of the hypothalamus produce oxytocin and vasopressin. These hormones are released into the blood in the posterior pituitary.[3] Much smaller parvocellular neurosecretory cells, neurons of the paraventricular nucleus, release…