Download ADENOHYPOPHYSIAL HORMONES

ADENOHYPOPHYSIAL HORMONES
DIRECT ACTIONS
Growth hormone releasing hormone (GHRH) ===> somatotrophin (GH) ===> somatic tissues
GH release inhibited by somatostatin
- promotes growth by stimulating proteins synthesis of virtually all tissues
sensory input ===> prolactin
prolactin release inhibited by prolactin inhibiting factor (PIF)
- stimulates milk production
MSH releasing factor ===> melanocyte-stimulating hormone (MSH; also released in response to
corticotrophin releasing factor; CRF)
- stimulates melanin synthesis in melanocytes
INDIRECT ACTIONS
Thyrotrophin releasing factor (TRF or TRH) ===> thyrotrophin or thyroid stimulating hormone
(TSH) ===> thyroid gland ===> thyroxine ===> tissues
- regulates development
- regulates metabolic rate in adulthood
Corticotrophin releasing factor (CRF) ===> corticotrophin or adrenocorticotrophic hormone
(ACTH) ===> cortisol, aldosterone
- cortisol in inhibits protein synthesis, stimulates gluconeogenesis (synthesis of glucose
from proteins), inhibits conversion of carbohydrates to fats
- aldosterone regulates electrolytes, especially sodium
Gonadotrophin releasing hormone (GnRH) or leuteinizing hormone releasing hormone (LHRH)
===> luteinizing hormone (LH) and follicle stimulating hormone (FSH) ===> gonads ===>
androgens or estrogens and progesterone
- sexual differentiation during development
- LH and FSH also stimulate gametogenesis and, in females, ovulation
NEUROHYPOPHYSIAL HORMONES
stimulation of cervix, nipples ===> oxytocin
- "turns on" maternal behavior
- stimulates mammary glands, causing milk ejection
low blood pressure ===> vasopressin or antidiuretic hormone (ADH)
- causes kidneys to retain more water