Week 1 Physiology Part 2

Front 1

describe how glucocorticoid remediable aldosteronism causes disease

Back 1

autosomal dominant primary aldosteronism. causes unequal crossing over of 11b hydroxylase gene to coding sequence of aldosterone synthase. aldosterone is thus regulated by ACTH instead of RAA system. Small doses of glucocorticoids cause hypertension.

Front 2

explain what happens to people without 11b hydroxysteroid dehydrogenase type 2 and why

Back 2

this is called syndrome of apparent mineralocorticoid excess, characterized by findings suggestive of a hypermineralocorticoid state. this is caused by impaired conversion of cortisol to cortisone. urinary cortisol is increased but plasma cortisol is normal.

Front 3

Detail the mechanism of aldosterone action on the kidney

Back 3

promotes the NA/K atpase activity and increases the # of Na channels in the luminal membrane thus increasing the passive movement of sodium from the filtrate into the cell. this also causes the lumen to become more negative, causing K efflux into the lumen.

Front 4

Detail the effects of increased K intake on plasma K, aldosterone, and renal K secretion

Back 4

Increased K+ causes increased Plasma K+, increased aldosterone, and increased K+ secretion

Front 5

Describe the effects of increased sodium intake on plasma aldosterone, GFR, Proximal tubular NA reabsorption, distal tubular flow rate, K secretion by cortical collecting ducts, and renal K excretion

Back 5

increase in Na leads to decrease in aldosterone
increased GFR
Descreased Proximal NA reabsorption
Increased flow rate in the distal tubules
K+ secretion increases, but the decreased Aldosterone balances this out so there is no net loss of K

Front 6

Describe the MOA of angiotensin, the receptor subtypes

Back 6

converted to A2 by ACE in the lungs. increases aldosterone secretion. A2 stimulates NA/H exchange in the renal PCT and increases reabsorption of HCO3 and NA.
AT1 receptor: located on arterioles to cause vasoconstriction
AT2 receptor: mediate effects on cell growth and differentiation in the heart, kidney, and smooth muscle
in the circumventricular organs, Angiotensin provokes drinking, and secretion of vasopressin.

Front 7

Name 2 drugs which cause increased Angiotensinogen and one that causes decreased angiotensinogen

Back 7

Essential HTN and oral contraceptives increses Angiotensinogen
Addison's Dx decreases it

Front 8

detail the fxns and derivations of the intermediate lobe of the pituitary hormones which are formed from POMC: beta endorphin, and MSH's

Back 8

MSH causes hyperpigmentation of the skin and are only significant in diseases like addison's disease. B-endorphin binds to opioid receptors throughout the CNS.