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42 Cards in this Set
- Front
- Back
which hormone makes up most of the anterior pituitary?
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GH
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stimulators of growth hormone
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ghrelin
opioids alpha-adrenergic protein load hypoglycemia sleep stress |
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inhibitors of growth hormone
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glucose load
fatty acids somatostatin beta-adrenergic |
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mechanism of GH signaling
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1. GHR dimerizes
2. recruits JAK2 3. JAK2 phos. GHR 4. recruit STAT5b 5. JAK2 phos STAT5b 6. STAT5b moves to nucleus 7. STAT5b binds IGF-1 promoter |
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GH excess before closure of epiphysis is called what
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gigantism
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most common isolated ant pit deficiency
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GH
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GHR mutations
Dwarfs conditions? |
Laron syndrome
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GH effect on carbohydrates
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^ circulating glucose
- reduce uptake in peripheral tissues - ^ neogenesis in liver |
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GH effect on lipids
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^ lipolysis in adipocytes
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glucose intolerance
hyperinsulinemia what is the defect? |
GH secreting tumor
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short and chubby
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GH deficiency
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how does GH mediate its effects?
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directly: glucose intolerance, hyperinsulinemia (tumor)
indirectly: IGF-1 |
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which substance circulates bound to a carrier protein
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IGF-1 to IGFBP
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effect of IGF-1 on GH action?
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oppose (feedback)
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what substances are used in GH stimulation testing to detect GH deficiency
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arginine (aa)
clonidine (a adrenergic) |
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what is somatotropin used for?
contraindication? |
treat GH deficiency
active malignancy, ICU |
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when would you use IGF-1 instead of GH to treat short stature?
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laron syndrome
primary IGF-1 deficiency GH antibodies |
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Mecasermin
what is it? complication? |
recombinant IGF-1
hypoglycemia & lipohypertrophy (insulin effects) |
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acromegaly/gigantism
causes? |
somatostatin
GH antagonist dopamine agonist |
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which somatostain analog do you use?
what does it do? |
octreotide over regular somatostatin (useless clinically)
acts DIRECTLY on somatotroph to inhibit GH release - also inhibits TSH release |
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what does Pegvisomant do?
when is it used? |
binds GH receptor w/o activation (antagonist)
when pt fails surgery/somatostatin |
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which two hormones are in the same cytokine receptor family?
what is their mechanism? |
GH & Prolactin
JAK2/STAT5 |
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PRL secretion stimulators?
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estrogen
suckling TRH |
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besides a tumor, what 2 other things can cause elevated PRL
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1. primary hypothyroidism (leads to elevated TRH, which ^ PRL)
- "hormone spillover" 2. antipsychotic drugs (dopamine antagonists) |
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what shares an a-subunit w/ TSH?
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LH
FSH |
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what type of receptors do LH, FSH, hCG have?
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G-protein
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what does hCG do?
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1. progesterone production by corpus luteum
2. testosterone production by Leydig cells 3. Pregnancy tests |
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FH function
Males active in which type of cells? feedback substance? |
Sertoli
spermatogenesis/differentiation Inhibin reduces FSH release |
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LH function
males active in which type of cells? |
Leydig
Testosterone production feeds back to reduce LH secretion |
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FSH
females cells? function? |
granulosa
stimulates aromatase to convert theca to androgens to estrogen |
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what happens in Theca cells?
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1. LH stimulates synthesis of androgens
2. FSH stimulates aromataseto convert androgens to estrogens |
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What happens in the corpus luteum?
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Granulosa-lutein cells synthesize both estrogen and progesterone
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what processes does GnRH control?
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puberty onset
mentraul cycle |
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diagnostic use of LH?
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look for surge
= optimal fertility |
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failure of normal testes descent
cause? tx? |
prenatal androgen deficiency
tx: hCG Crytochordism |
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effect of prolonged stimulation of GnRH agonists?
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Desensitization
- GnRH receptor down-regulation - decreased GnRH secretion |
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effects of Leuprolide?
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suppress puberty
maximize adult height synthetic GnRH agonist (down regulates LH and FSH secretion = reduction in estrogen) |
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woman wants to get pregnant?
approach? |
1. exogenous gonadotrophins ^ maturation of follicles and sperm
2. use GnRH receptor agonists & antagonists to shut down endogenous gonadotropins (better control w/ exogenous ones) |
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large growth but not pituitary thyroid tumor
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primary hypothyrodism
(thyrotrophs hypertrophy) |
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what do you use to monitor thyroid cancer?
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thyrotropin
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what do you use to diagnose adrenal insufficiency (primary & secondary)
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Cortrosyn
|
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microphallus
hypoglycemia mid-face hypoplasia condition? |
EMERGENCY
congenital Panhypopituitism |