Pituitary Gland

About the Pituitary Gland

The pituitary gland hypophysis is a pea sized gland approximately 0.5 grams sitting in the sella turcica of the sphenoid bone, connected to the hypothalamus by the infundibular pituitary stalk. It is the master gland, controlling growth, metabolism, reproduction, and stress response. The anterior pituitary adenohypophysis 80 percent originates from Rathke pouch oral ectoderm and produces six hormones: GH growth hormone, PRL prolactin, ACTH adrenocorticotropic hormone, TSH thyroid stimulating hormone, FSH follicle stimulating hormone, LH luteinizing hormone. Hypothalamic releasing hormones GHRH, TRH, CRH, GnRH control their release, with feedback from target gland hormones. The posterior pituitary neurohypophysis is neural tissue, storing and releasing ADH vasopressin from supraoptic nucleus and oxytocin from paraventricular nucleus, produced in the hypothalamus. Pituitary tumors adenomas cause hormone excess acromegaly from GH, Cushing disease from ACTH, prolactinoma or deficiency hypopituitarism. Pressure on the optic chiasm causes bitemporal hemianopsia. Sheehan syndrome postpartum pituitary necrosis causes failure to lactate and amenorrhea.