Endocrine Flashcards
what hormones do the anterior pituitary secrete? (also called adenohypophysis)
FSH LSH ACTH TSH Prolactin GH Melantropin
What hormone does the posterior (neurohypophysis)?
Vasopressin
Antidiuretic hormone
ADH
oxytocin
What are the parts of the pancreas?
Islets of Langerhans (alpha, beta)
Alpha= gulcagon
B= insulin
Gamma= somatostatin
What are the steps of insulin?
pre-pro insulin to proinsulin to insulin
Briefly describe the mechanism of insulin?
Binds to insulin receptors on the cell
Induces glucose uptake
Gene transcription
Does insulin cross the placenta?
No, but glucose does
Which are insulin dependent transporters?
GLUT 4 (adipose tissue) striated muscle
Which one are insulin -dependent transporters?
GLUT 1: RBC (brain, cornea)
GLUT 2: liver, kidney, small intestine
GLUT 3: brain, placenta
GLUT 5: fructose
What does glucagon do? What cells secrete it?
1) Made by alpha cells of the pancrease
2) Catabolic effects (glycogenesis, gluconeogenesis)
3) Lipolysis and ketone production
4) Secreted in response to hypoglycemia
5) Inhibited by insulin, hyperglycemia, and somatostatin
What are the hypothalamic-pituitary hormones?
1) CRH
2) Dopamine
3) GHRH
4) GnRH
5) Prolactin
6) Somatostatin
7) TRH
What does CRH do?
Increases ACTH, MSH, B endorphin
Decreased in chronic exogenous steroid use.
What does dopamine do?
Decrease prolactin
Increase TSH
Dopamine antagonists can cause galactorrhea due to hyperprolactinemia
What does GnRH?
Increased FSH, LH
Suprreses hyperprolactinemia
What does prolactin do?
Decrease GnRH
If have a prolactinemia —>amenorrhea, osteoporosis, hypogonadism, galactorrhea
What does somatostatin do?
Decrease GH, TSH
Used to treat acromegalu
What does TRH do?
Increased TSH, prolactin
Function of prolactin?
Stimulates milk production in the breast
Inhibits ovulation in females and spermatogenesis in males
Too much prolactin leads to decreased libido
How does prolactin inhibit it’s own production?
prolactin is secreted by anterior pituary
(inhibited by dopamine)
Prolactin will inhibit its own secretion by STIMULATING dopamine
How are prolactinemia treated?
Bromocriptine (dopamine agnosit) inhibits the secretion of prolactin
What are side effects of dopamine antagonists? what are common dopamine antagnoists?
1)antipyschotics
They will stimulate the production of prolactin
What does the growth hormone Somatotropin do?
Secreted by the anterior pituitary
Stimulates linear growth and muscle mass
Secretion is increased during exercise or deep sleep
Released when pulse of GHRH
Excess GH leads to gigantism or acromegaly
What are the hormones responsible for appetite regulation?
1) Grehlin
2) Leptin
3) Endocannabinoids
What does Ghrelin do?
What increases production?
1) Stimulate hunger and GH release
2) Sleep deprivation and Prader-Willi can increase production
What does leptin do?
Satiety hormone
Produced by adipose tissue
Can be produced by sleep deprivation or starvation