Term
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Definition
hypothalamic pituitary axis |
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Term
what does it mean when said HPA is dinural |
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Definition
higher activity in morning |
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Term
what can increase the HPA axis activity the best |
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Definition
stress, which can over ride normal feedback controls |
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Term
what does ACTH stand for, what is its job |
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Definition
adrenocorticotrophic hormones
stimylates adrenal cortex to secrete glucocorticoids, mineralcoricoids, weak androgens |
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Term
what are two weak androgens |
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Definition
andeostendione dehydropiandrosteone |
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Term
what are the three zones of the adrenal cortex |
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Definition
zona glomerulosa - outer zona fasculata - inner zona reticularis - inner |
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Term
what enzymes does cortex outer zone have, what does it secrete |
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Definition
secretes aldosterone (mineralcorticoids) via aldosterone synthase |
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Term
how is mineralcorticoid production stimulated |
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Definition
ACTH acutely stimulates
angiotensin II receptors with Gs protein initiate it |
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Term
what happens to the cortex if it does not get enough stimulation |
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Definition
does not atrophy without pituitary stimulation |
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Term
what enzymes does the cortex inner zones have, what do they secrete |
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Definition
12-a-hydroxylase, 11-B0hydroxylase
secretes glyucocorticoids |
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Term
what stimulates inner cortex, what if there is too much stimulation |
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Definition
increases in ACTH cause hyperplasia, hypertrophy, increased cortisol and androgens |
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Term
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Definition
ACTH increases due to impaired cortisol synthesis |
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Term
what happens if the inner cortex does not get stimulation |
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Definition
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Term
what occurs in the acute phase of steroid production |
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Definition
within seconds increased supply of cholesterol to substrate (depends on amount of cholesterol) |
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Term
what occurs in the chronic phase of steroid production |
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Definition
within hours steridogenic enzyme transcription is increased |
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Term
where are most of the enzymes for steroid production |
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Definition
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Term
explain the process of steroid hormone production (3 steps) |
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Definition
1. cholesterol is turned into pregnilone via CHOLESTEROL SIDE CHAIN CLEVAGE ENZYME (P450 SCC) **RATE LIMIT
2. pregnilone is turned into cortisol, aldosterone, and adrenal androgens
3. products go to receptors and cause transcription. their structures are similar and they can activate e/o receptors |
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Term
how is production of cortisol stimulated |
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Definition
hypothalamus releases CRF and AVP which activate pituitary which releases ACTH which acrivates adrenal gland which releases cortisol |
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Term
what controls rate of cortisol production |
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Definition
ACTH release from pituitary corticotropes which are regulated by corticotropin releasing hormone (CRH) |
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Term
how is cortisol production/stimulation regulated (2) |
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Definition
ACTH can stimulate production but will burn out so it stops activity in hypothalamus
cortisol (glucocorticoids) stop activity in pituitary and hypothalamus |
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Term
cortisol and aldosterone bind same receptors for same affinity, how does the body discriminate |
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Definition
in mineralcorticoid (ALD) receptors it has enzyme barrier with 11-B-hydroxy DH that metabolizes cortisol to cortisone which cannot bind ALD receptor |
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Term
what are the 7 areas / systems that corticosteroids effects |
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Definition
carb and protein metabolism lipid metabolism cardiovascular skeletal muscle CNS blood immune supression/anti-inflammatory |
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Term
what do corticosteroids do to carb and protein metabolism |
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Definition
protect glucose dependent tissues from starvation (brain and heart)
glucogenolysis glyconeogenesis diminish glucose utilization in tissue
cause protein break down |
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Term
what do corticosteroids to to lipid metabolism |
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Definition
stimulate lipolysos increase fat in neck (buffalo hump) and face (moon faces) loss of fat in extremities |
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Term
what do corticosteroids to do skeletal muscle |
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Definition
needed for normal function decreased muscle work due to adrenocorticol insufficiency (addison's disease) hypercorticism: causes muscle wasting |
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Term
what effects do corticosteroids have on CNS (5) |
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Definition
mood, behavior, brain excitability
in cushings and addisons: neuroses, psychoses |
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Term
what does corticosteroids do to the immune system (7) |
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Definition
decreases cytokine production, lymphocyte response, histamines, leukotrienes, arachadonic acid release via phospholipase A2 inhibition supress inflammation decrease WBC circulation |
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Term
what are the HPA axis drugs (2) |
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Definition
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Term
what are the short acting glyucocorticoids (2) |
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Definition
|
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Term
what are the intermediate acting glucocorticoids (3) |
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Definition
prednisone methylprednisolone triamcinolone |
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Term
what are the long acting glucocorticoids (2) |
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Definition
betamethazone dexamethazone |
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Term
what are the corticosteroid inhibitors (3) |
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Definition
aminoglytethimide ketoconazole spironolactone |
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Term
what are the mineral corticoids |
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Definition
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Term
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Definition
high concentrations affect hypothalamus, stimulate corticoid and androgen receptors testing HPA axis |
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Term
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Definition
tests HPA axis ysing synthetic ACTH residues 1-24 |
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Term
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Definition
antigenic: comes from animals
vasopressin par causes hyponatremia |
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Term
short acting glucocorticoid MOA |
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Definition
metabolized via reduction in liver to 11-8-hydeoxyderivative to be active |
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Term
side effects of short acting glucocirticoids (4) |
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Definition
antiinflammatory salt retension minteral corticoid effects less potent |
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Term
side effects of intermediate acting glucocorticoids (3) |
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Definition
more potent low salt retension low mineralcorticoid effect |
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Term
side effects of long acting glucocorticoids (3) |
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Definition
most potent no salt retension no mineralcorticoid effect |
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Term
shared side effects of all glucocirticoids (12) |
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Definition
withdrawl: flare of of disease acute adrenal insufficiency HPA supression fluid and electrolyte imbalance hypertension hyperglycemia fat redistribution osteoperosis myopathy behavorial changes cataracts increased infection |
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Term
why do glucocirticoids cause acute adrenal insufficiency |
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Definition
due to rapid withdrawl after prolonged use |
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Term
who do glucocirticoids cause HPA supression |
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Definition
occurs with supraphysiologocal doses for 2wk + |
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Term
how do glucocirticoids cause osteoperosis |
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Definition
inhibit ostroblasts and decrease bone formation |
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Term
how are glucocirticoids administered (9) |
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Definition
oral, injected, inhaled, topical, optic, opthalamic, enema, rectal, retro rocket |
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Term
where are glucocirticoids metabolized and eliminated |
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Definition
metabolized in liver excreted in kidney |
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Term
what affects the distribution of glucocirticoids |
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Definition
90% bound to proteins (corticosteroid binding globulin, transcortin, albumin) |
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Term
what are the clinical uses of glucocirticoids (15) |
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Definition
adrenal insufficiency chronic primary adrenal insufficiency congenital adrenal hypoplasia RA SLE degrnerative joint regional pain syndrome (injection) allergies asthma PJP influenza virus ocular disease: supresses inflammation but increases IOP cerebral edema stroke spinal cord injuty |
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Term
what are 2 diseases that cause chronic primary adrenal insufficiency |
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Definition
adrenal surgery
cortex lesion (addisons) |
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Term
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Definition
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Term
aminoglytethimide clinical use |
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Definition
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Term
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Definition
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Term
ketoconazole clinical use |
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Definition
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Term
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Definition
competes for mineralcorticoid receptor and stops Na reabsorption |
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Term
spironolactone clinical use |
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Definition
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Term
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Definition
act on DCT to increase reabsorption of Na into plasma and excretion of K and H |
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Term
fludorcortisone clinical use (4) |
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Definition
addisons severe salt loss adrenogenital syndrome orthostatic hypotension |
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