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30 Cards in this Set
- Front
- Back
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What is the adrenal gland thought of anatomically?
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2 triangles (outer is cortex and inner is medulla)
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What is adrenal medulla considered to be?
Therefore function? |
"extension of the SNS"
fx: nervous innervations humoral/endocrine actions |
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Cell that release epi and norepi?
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chromaffin cells
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Basic path to synthesize of catecholamines?
What enzyme induces the last step and what induces it?? |
Tyrosine (rate limiting)--> dopa--> Dopamine--> Norepinephrine--> Epinephrine
-PNMT induced by cortisol |
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In degredation of epinephrine and norepinephrine (degredation of catecholamines) what enzyme cause both to become the same thing?
What enzyme changes epi and norepi to something different and what is different products? |
MOA (monoamine oxidase) turns both into 3,4 dihydroxymandelic acid
Catechol-O-methyl transferase (COMT) 1. epi- metanephrine 2. norepi- normetanephrine |
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What are the four possible urinary metabolites from catecholoamine degredation measured and what enzymes are necessary for their creation?
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Urinary metabolites:
1. Dyhydroxymandelic acid (1) 2. metanephrine (2) 3. normetanephrine (2) 4. vanillylmandelic acid (VMA) (1,2) All step from either 1. MAO or 2. VMA |
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Action on cardio part after slow infusion of norepinephrine...
a. systolic/diastolic pressure b. vasoconstriction (a1) c. heart rate d. cardiac output |
a. increased both
b. increased c. decreased d. decreased |
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Action on cardio part after slow infusion of epinephrine...
a.vessels in skeletal muscles and liver predominate b. vasoconstriction (a1) c. heart rate d. cardiac output |
a. dilation of vessels in skeletal muscles and liver predominate
b. decreased c. increased d. increased |
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Catecholamines metabolic effect on:
a. blood glucose b. fatty acids |
a. increased
b. increased by lipolysis |
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Greatest source of norepinephrine and epidnephrine comes from what?
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epi- adrenal medulla
nor- sympathetic nervous system therefore hyposecretion of the adrenals does not mean you dont have norepinephrine in the blood |
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Major cause of adrenal medula hypersecretion
Symptoms? |
pheochromocytoma (tumor of adrenal medulla)
hypertension, palpitations, chest pain headaches, anxiety, sweating |
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Medication treatment of pheochromocytoma
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phenoxybenzamine administration
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1. What hormones are secreted from the zona glomerulosa?
2. Zona fsciculata 3. reticularis |
1. mineralocorticoids (aldosterone)
(deoxycorticosterone) 2. glucocorticoids- (cortisol) (corticosterone) sometimes androgens 3. Androgens- (dehydroepiandosterone, androstenedione) |
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Precursor from steroids we get from zona reticularis of adrenal cortex?
Where does the cholesterol come from? |
pregnenolone (cholesterol)
- most comes in blood as lipoproteins most of which are LDL |
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What is missing (Morrill) when you dont have the enzyme 17-a-hydroxylase?
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Will have an overabundance of mineralocorticoids but no androgens, or glococorticoids
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What is lowest point of cortisol during the day?
- Highest? |
12 am
- 8 am at highest Know when it was collected |
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How is Aldosterone stimulated to be released?
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Decrease BP and Blood volume causes Kidney to release renin stimulating angiotensin to become AngI and ACE converts it to ANGII
Angio II stimulates adrennal cortex |
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Other stimulators of aldosterone besides AngII?
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elevated K, ACTH, and decreased Na
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Cortisol is mostly bound to?
% aldosterone free and biologically active? |
90% corticosteroid- binding glovbn
6% albumin 4% is free and biologically active 40% aldosterone free |
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How doe adrenocorticosteroids act?
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1. genomic- DNA through protein synthesis
2. non-genomic- membrane receptor--> second messenger |
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Action of glucocorticoids?
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- increased blood glucose
1. decreasing insulin sensitivity in skeletal muscle and adipose 2. increases hepatic gluconeogenesis 3. protein breakdown 4. lipid mobilization 5. bone resportion 6. Decrease inflammation and immune response |
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What relationship does glucocorticoids have with catecholamines?
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permissive for some of the catecholamines (glucocorticoids are key to lock so catecholamines can go in and do job)
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What is cross talk?
What hormones utilize cross talk? |
Cross talk- ability of one hormone to bind to more than one receptor and exhibit different actions---
- see in steroid hormones |
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Hypocortisolism causes?
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decreased blood glucose, when fasting too long,
- increased insulin sensitivity - decreased resistance to stress and disease |
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Hypercortisolism causes?
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Cushings'
Disease- excess pituitary ACTH Syndrome- excess ectopic ACTH hypersecreting gland/tumor excess administration of cortisol |
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Main action and where of adosterones
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DCT, and cortical collecting ducts
- renal reabsorption of Na - renal excretion of K/H |
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MCCs of hypoaldosteronism
Effects? |
autoimmune, TB, carcinoma
effects- decreased bp, decreased plasma Na, increased plasma K |
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Secondary adrenocortical insufficency shows what?
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about normal aldosterone secretion, but there is a lack of ACTH so the glucocorticoids are low
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Primary adrenocortical insufficiency aka?
Causes? Resulting effects? |
aka Addison's Disease
Causes: insufficient production/ secretion of glucocorticoids and mineralocorticoids Resulting in: weakness and fatigability, hyponatremia, hyperkalemia, hypotension, hyper pigmentation, death |
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Adrenogenital syndrome enzyme problem?
levels of Mineralocorticoids Cortisol Sex hormons |
21-hydroxylase-
mineralocorticoids- down cortisol- down sex hormones- up - masculinization with female pseudohermaphroditism |
