What is the relation between the hypothalamus and the hypophysis?
The hypothalamus is a part of the brain situated just above the hypophysis. The hypothalamus gets peripheral and central neural impulses that trigger response of its neurosecretory cells. The axons of these cells go down to the adenohypophysis to regulate the hipophyseal secretions by means of negative feedback. When the plasma levels of adenohypophyseal hormones are too high the hypothalamus detects this information and commands the interruption of the production of the hormone. When the blood level of an adenohypophyseal hormone is low the hypothalamus stimulates the secretion of the hormone. The hypothalamic cells produce the hormones released by the neurohypophysis. These hormones are transported by their axons to the hypophysis and then released in the circulation.