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49 Cards in this Set
- Front
- Back
What are the parts of the body that make up the hypothalamic-pituitary-adenal axis?
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hypothalamus
anterior pituitary adrenal cortex |
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Name the steps that lead to the release of glucocorticoids
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hypothalamus synthesize and secrete corticotropin releasing hormone (CRH)
CRH stimulates anterior pituitary to release adrenocorticotropic hormone (ACTH) ACTH stimulates adrenal cortex to release glucocorticoid hormones |
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What does glucocorticoid hormone feedback to?
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anterior pituitary and hypothalumus
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What can override the normal negative feedback control mechanisms leading to increased plasma levels of glucocorticoids
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stress
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Where is CRH produced?
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paraventricular nucleus of hypothalamus
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What are the clinical applications of CRH?
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diagnostic purposes
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What am I:
the precursor protein to ACTH |
pro-opiomelanocortin (POMC)
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What am I:
the first 13 amino acids of ACTH cleaved |
alpha-melanocyte stimulating hormone
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During what time of the day does ACTH have its highest plasma level?
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early morning
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Why do patient's with Addison's disease often present with skin hyperpigmentation?
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because ACTH has a common structure of MSH
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What am I:
stimulate the synthesis and distrubution of melanin in melanocytes in mammals |
melatonin stimulating hormone
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What primarily influences of the secretion of mineralocorticoid aldosterone?
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angiotensin
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What receptor does ACTH acto through?
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G protein coupled ACTH receptors on adrenocortical cells
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What is the clinical application of ACTH?
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diagnostic purposes - tests integreity of HPA axis
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What are the 3 compartments of the adrenal cortex?
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zona glomerulosa
zona fascuculatat zona reticularis |
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What are all glucocorticoids synthesized from?
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cholestorol
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What is the main glucocorticoid in humans?
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cortisol
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True or false, cortisol is important for the circadian rhythm?
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true
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Are there more bound or unbound cortisol in circulation?
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unbound
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What differentiates the different classes of corticosteroids?
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length of activity, and allergic reactions
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True or False:
Corticosteroid are not diurnal |
False: they are diurinal
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What are the metabolic effects of glucocorticosteroids?
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stimulate protein breakdown in extrahepatic tissue
stimulate triglyceride breakdown in adipose tissue stimulate gluconeogenesis in liver inhibit glucose uptake in muscle and adipose tissue overall increase ATP |
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What are the catabolic effects of GC?
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stimulate breakdown of lymphoid and connective tissue, muscle, bone and skin
cause growth reduction in children |
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What are the anti-inflammatory effects of GC?
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inhibits function of immune cells
suppress release of pro-inflammatory cytokines and PGs |
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What are teh CNS effects of GC?
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induce insomnia, euphoria, depression
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What are the naturally occurring GC?
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cortisol (hydrocotisone)
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What are the synthetic GC?
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prednisone
prednisolone dexamethasone |
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What am I:
am a glucocorticosteroid longer duration of action and stronger anti-inflammatory effects less plasma protein binding |
synthetic GC
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How are GC metabolized?
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glucoronidation
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What is the MOA of GC?
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regulation of gene suppression by:
diffuse across cell membrane to bind to cytosolic and nuclear receptors Dimerize with receptor and binds to GRE this initiates transcription and translation |
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What are the therapuetic uses of GC?
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diagnostic pursposes
replacement therapy for adrenal insufficiency (addison's disease) anit-inflammatory/immunosuppressive effects |
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What are the two ways that can lead to an adrenal cortex disorder?
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primary dysfunction of adrenal cortex (primary)
pituitary disorder (secondary) |
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What disease am I:
increase plasma cortisol levels decrease ACTH levels primary disorder |
cushing's syndrome
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What disease am I:
increase plasma cortisol levels increase plasma ACTH levels secondary disorder |
cushings disease
pseudo-cushings syndrome |
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What disease am I:
decrease plasma cortisol decrease ACTH secondary |
sheehans syndrome
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What disease am I:
decrease cortisol increase ACTH primary |
addison's disease
nelson's syndrome |
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What disease am I:
caused by excessive anterior pituitary secretion of ACTH leading to increased cortisol |
cushing's disease
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What disease am I:
increased cortisol leading to decreased ACTH |
cushing's syndrome
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What are the causes of adrenocortical hyperfunction?
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pituitary hypersecretion of ACTH
non-pituitary tumor secretion of ACTH adrenal tumor secretion of cortisol GC drug administration |
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What are the clinical manifestations of adrenocortical hyperfunction?
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weight gain and fat redistribution
thin extremities, muscle wasting and weakness diabetes hypertension osteoporosis menstrual irregularities |
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What is the diurnal rhythm of cortisol levels?
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high in morning, low at night
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True or False:
Diurnal rhythm is present in adrenocortical hyperfuntion |
False
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What am I:
1mg of this drug is taken at by mouth at night plasma cortisol is taken in the next morning if plasma cortisol level is low in morning, pts is normal if plasma cortisol level is maintained from night before, pt have cushing's syndrome |
dexamethasone test
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What are the two causes of side effects with GC therapy
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chonic use at high doses
sudden withdrawal (should titrate down if use is for longer than 2 weeks) |
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What is the most important mineral-corticoid in humans?
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aldosterone
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What is the direct precusor to aldosterone, cortisol, and testosterone?
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progesterone
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What is the mechanism of action of aldosterone?
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binds to mineralocortioicd receptors (nuclear receptors) to activate transcription and translation
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What am I:
a synthetic mineralocortiod used to reat adrenocortical insufficiency (addison's disease) |
fludrocortisone
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What am I:
A synthetic mineralocortioid an mineroalcorticoid antagonist ued to treat hyperaldosteronism |
spironolactone
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