SECRETS Endo - Pituitary Flashcards
Sheehan syndrome
postpartum necrosis
infarct of anterior pituitary
susceptibility of pituitary to hemorrhage postpartum
during pregnancy = hyperplasia of lactotrophs without increase in blood supply
sparing of posterior pituitary in Sheehan
posterior pituitary has alternate blood supply
embryo anterior pituitary
Rathke’s pouch
embryo post pituitary
ventral outgrowth from primitive hypothalamus
anterior pit hormones
FSH LH ACTH TSH prolactin GH
post pit
oxytocin
ADH
dopamine - prolactin
dopamine inhibits prolactin secretion
prolactinoma
most common type of hypersecreting pituitary adenomas
situated in sella turcica
prolactin levels before, during, after pregnancy
before = normal, tonic inhibition by depamine
during = elevated 2/2 high estrogen, but lactation is inhibited by high estrogen & progesterone
after = elevated due to suckling
inhibit GnRH = anovulatory infertility while nursing
prolactinoma sx
galactorrhea, infertility, malaise, depression
in men - impotence, lack of libido
prolactin - FSH/LH
prolactin inhibits GnRH –> decrease FSH, LH
infertility, amenorrhea
tx hyperprolactinemia
dopa agonists
bromocriptine
tuberoinfundibular tract disruption
- all ant pituitary hormones except prolactin++
causes hyperprolactinemia
prolactinoma, antipsychotics, hypothyroidism, breast feeding/excessive nipple stimulation
acromegaly
++ GH
GH-secreting tumor
middle aged adults
hyperglycemia in acromegaly
GH –> + serum glucose –> diabetes
body’s mechanism to prevent serious hypoglycemia
GH secretion times
nighttime
GH inhibition
somatostatin, glucose, emotional stress, malnutrition, obesity, glucocorticoids, decreased thyroid hormone
acromegaly sx
gradually enlarging hands, feet, coarsening face
prominent jaw, organomegaly
IGF-1
anabolic effect on bones
metabolic effects
secreted by liver
tx acromegaly
somatostatin
analog octreotide
secreted by hypothalamus, pancreatic islets, gastric mucosa
(inhibits stuff)
++ GH in kids
gigantism
epiphyseal plates have not closed yet
pituitary dwarfism
deficient GH, proportional
achondroplasia
dwarfism that is not proportional
mutation in FBFR3 = inhibit bone growth
GH effects
anabolic on skeletal muscle, bone
lipolysis in adipose tissue
stimulate gluconeogenesis
antagonizes insulin
