ENDO Flashcards
(121 cards)
Portal system structure
portal system-capillaries->vein->enter another capillary bed provides rapid delivery of controlling hormones from hypothalamus to anterior pituitary
GnRH does
controls release of LH and FSH from gonadotroph cells.
GnRH
Gonadotropin releasing hormone
GnRH purpose and target organ
stimulates LH+FSH in ant pituitary
GnRH->ant. Pituitary gonadotrophs->LH+FSH->gonadotropin->ovaries/testes
GnRH and FSH inhibited by
GnRH and FSH are inhibited with negative feedback loop @hypothalmus/gonadotrophs by increased levels of estrogen in women/testosterone in men
PRH purpose and target organ
Prolactin releasing hormone->ant. Pituitary lactotrophs->prolactin releasing hormones go to mammary glands.
PRH
Prolactin releasing hormone
PRH inhibited by
inhibited by Prolactin inhibiting hormone/PIH. PIH structurally a dopamine and regulated by estrogen
CRH
corticotropin releasing hormone
CRH purpose and target organ
stimulates ACTH to be released.
Hypothalamus->CRH->ant. Pituitary corticotrophs->ACTH/corticotropin->adrenal cortex(zone fasciculata)->cortisol
CRH inhibited by
Cortisol negative feedback to corticotrophs and hypothalamus to inhibit CRH and ACTH
TRH stimulates
Production of TSH
TRH:
Thyrotropin releasing hormone
TRH purpose and pathway
stimulate production of TSH
Hypothalamus->TRH->ant. Pituitary thyrotrophs->TSH/thyrotropin->thyroid(target)->T3+T4
TSH purpose
TSH stimulates thyroid to produce T3+t4
TSH
Thyrotropin
TRH inhibitor/regulator
T3+T4
GHRH
growth hormone releasing hormone
GHRH
growth hormone releasing hormones:
GHRH purpose
stimulates somatotrophs to release GH(growth hormone.
GHRH pathway
Hypothalamus->GHRH->ant. Pituitary somatotrophs->GH/growth hormone->liver-> IGF/insulin like growth factor-> blood sugar increases
IGF
Insulin-like growth factor
IGF produced in
the liver
GHRH inhibited
by GHIH/growth hormone inhibiting hormone and affected by blood glucose levels