The hypothalamus controls the anterior pituitary by means of
Releasing hormones
Inhibiting hormones
The hypothalamus controls production and secretion of the anterior pituitary hormones. Neurons in the hypothalamus secrete releasing and inhibiting hormones into the circulatory system and regulate the functions of the anterior pituitary. For example, thyrotropin-releasing hormone (TRH) stimulates the release of TSH, corticotropin-releasing hormone (CRH) stimulates the release of ACTH, etc. The hypothalamus also secretes hormones that inhibit the release of certain anterior pituitary hormones. Three such hormones are: somatostatin which inhibits the secretion of GH; prolactin-inhibiting factor (PIF) which inhibits the secretion of prolactin, and melanotropin-inhibiting hormone (MIH) inhibits the secretion of MSH.