normal renal function and diuretcis Flashcards
Where is magnesium resorbed in the kidney?
Mg resorbed through paracelluar diffusion in the ascending LOH
How is calcium resorbed in the kidney?
Ca is resorbed via paracellular diffusion in the ascending LOH; Ca is also resorbed in the DCT depending on parathyroid hormone activity
What is the difference between the collecting tubule and the collecting duct?
the collecting tubule is in the kidney cortex; the collecting duct is in the kidney medulla
What do the principle cells do?
they are in the collecting tubule/duct. They drive Na resorption and K secretion when stimulated by aldosterone
What do the intercalated cells of the kidney do?
They secrete H+ and resorb K
What are the indications and adverse effects of acetazolamide?
Indications: glaucoma, epilepsy?, altitude sickness, metabolic alkalosis
Side effects: metabolic acidosis (prevents resorption of HCO3- in PCT via carbonic anhydrase inhibition), hypokalemia, nephrolithiasis
What are the adverse effects of loop diuretics? What are the effects on calcium?
Loops indirectly inhibit calcium resorption and so can be used in hypercalcemia (loops loose calcium)
ototoxicity, hypokalemia, gout, interstitial nephritis
What are the adverse effects of thiazides? What are their effects on calcium?
Inreases calcium resorption- can be useful for hypercalciuria.
can cause hyperuricemia, hyperlipidemia, hypercalcemia,
What is triamterene/amiloride?
blocks Na-K exchanger in the cortical collecting tubules. used in HTN as a K sparing diuretic
What is the signifcance of pyuria with waxy casts?
interstitial disease or obstruction
What is the FENa and how do you interpret it?
(Serum creatinine * urine sodium)/(Serum Na * urine creatinine). less than 1% suggests prerenal disease (you are trying to hold onto sodium in setting of low perceived volume); greater than 2% suggests ATN (and much higher suggests post-renal cause)
What is renal osteodystrophy?
bone degeneration due to low serum calcium; tests show low calcium and vitamin D with high parathyroid and phosphate
