Flashcards in endo p 317 - 321 Deck (58):
what is another name for growth hormone?
what are the 3 functions of growth hormone?
1. stimulates linear growth
2. stimulates muscle mass
3. inc insulin resistance (diabetogenic)
growth hormone stimulates muscle mass through
IGF-1 (somatomedin C)
2 functions of ghrelin?
1. stimulates hunger (orexigenic effet)
2. release GH via GH secretagog receptor
ghrelin is produced by
ghrelin is inc with what 2 conditions?
1. inc with sleep loss
2. prader-willi syndrome
leptin is made by
mutation is what gene causes congenital obesity?
mutation of leptin gene
what condition leads to dec leptin production?
what stimulates cortical reward centers and inc desire for high fat foods?
what receptor regulates serum osmolarity and blood pressure?
V1 - receptors --> regulate bp
V2 --> regulate osmolarity
antidiuretic hormone is synthesized in
supraoptic nuclei in hypothalamus
name hormones/signaling pathways associated with intrinsic tyrosine kinase
insulin, IGF-1, FGF, PDGF, EGF, MAP kinase pathway, (think growth factors)
calcitonin opposes the action of
calcitonin blocks what type of bone cell?
zona fasciculata produces
zona reticularis produces
zona glomerulosa produces
ACTH stimulates what enzyme?
cholesterol desmolase is inhibited by
cholesterol desmolase converts cholesterol to
what are the 2 roles of 17 alpha hydroxylase?
1. converts pregnenolone to 17-hydroxypregnenolone
2. converts pregesterone to 17-hydroxypregnenolone
2 drugs that block aromatase
what blocks 5 alpha reductase?
symptoms of 17 alpha hydroxylase def in XY/XX
XY: ambiguous genitalia, undescended testes
XX: lacks secondary sexual development
what blocks the conversion of cortisol to cortisone?
what stimulates aldosterone synthase?
what enzyme def is associated with dec renin?
11 beta hydroxylase
what enzyme def is associated with inc renin and inc 17 hydroxy progesterone?
2 reasons that cortisol inc blood pressure
1. upregulates alpha 1 receptors on arterioles --> inc sensitivity to norepinephrine and epinephrine
2. at high conc., can bind to aldosterone receptor
what property of cortisol lead to purple striae?
dec fibroblast activity
cortisol dec bone formation by dec activity of what cell?
what is the level of renin and aldosterone in 17 alpha hydroxylase def?
low renin, low aldo
what is the potassium level high or low in 17 alpha hydroxylase def?
what explains the low serum K+ in 17 alpha hydroxylase def?
11-deoxycorticosterone acts similar to aldoesterone leading to hypokalemia and metabolic alkalosis
what congenital adrenal enzyme def mimics addison dz?
21 hydroxylase def (b/c of high ACTH and low cortisol, hyperkalemia)
what congenital adrenal enzyme def mimics conn's syndrome?
both 17 alpha hydroxylase def and 11 beta hydroxylase def (b/c of low renin activity, hypokalemia due to high 11 DOC)
how is cortisol regulated?
CRH from hypothalamus stimulates ACTH release from pituitary that stimulates cortisol production in adrenal zona fasciculata
describe the effect of excess cortisol on CRH, ACTH?
dec CRH, dec ACTH
what acid/alkalosis disturbance can lead to hypocalcemia?
alkalosis (inc pH) --> inc affinity of albumin to bind Ca2+, leading to hypocalcemia
symptoms of hypocalcemia?
cramps, pain, paresthesias, carpopedal spasm
what are the effects of inc sex hormone binding globulin in men and women?
in men, inc SHBG leads to low free testosterone --> gynecomastia
in women, dec SHBG leads to inc free testosterone --> hirsutism
what 2 conditions lead to inc SHBG in women?
OCPs, pregnancy (b/c estrogen inc SHBG synthesis)
name the 4 functions of parathyroid hormone
1. inc bone resorption of Ca2+ and PO43-
2. inc kidney reabsorption of Ca2+ in distal convoluted tubule
3. dec reabsorption of PO43- in proximal convoluted tubule
4. inc 1, 25 (OH)2D3 (calcitriol) production by stimulating kidney 1 alpha hydroxylase in proximal convoluted tubule
explain how PTH leads to the activation of osteoclast which leads to inc serum Ca2+
inc production of macrophage colony-stimulating factor and RANK-L (receptor activator of NF-KB ligand)
RANK-L (ligand) is secreted by
RANK (receptor) is on what cell?
how does RANK-L and RANK interact to stimulate Ca2+ release?
RANK-L (ligand) secreted by osteoblasts and osteocytes binds RANK (receptor) on osteoclasts and their precursors to stimulate osteoclasts and inc Ca2+
will low serum Mg2+ stimulate or inhibit PTH secretion?
what about very low serum Mg2+?
stimulate PTH (however, very low serum Mg2+ dec PTH)
name 4 common causes of low serum Mg2+, thus can cause hyperparathyroidism
name all the hormones that use cAMP
ADH (V2 receptor)
name all the hormones that use cGMP
ANP, BNP, NO
name all the hormones that use IP3
name all the hormones that use receptor-associated tyrosine kinase
Immunomodulators (cytokines, IL-2, IL-6, IFN)
2 functions of vit D?
1. inc absorption of dietary Ca2+ and PO43-
2. inc bone resorption --> inc Ca2+ and PO43- absorption
what form of vit D is from sun exposure?