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9 Cards in this Set
- Front
- Back
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How does aldosterone alter the composition of urine/blood?
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By upregulating the CCD's Na+ channels and Na+/K+ pump, it enhances K+/H+ excretion, and Na+ & H2O reasorption
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Acetazolamide acts up on the proximal tubule. What is it's target and what effect does it have on excretion and pH
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It acts upon the carbonic anhydrase enzyme, preventing H+ generation and thus lowering bicarbonate which can be reabsorbed. Can favor metabolic acidosis, as excess Na+/HCO3- is excreted (taking water with it). This sodium is partially exchanged for K+ later in the nephron
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Where and how do loop diuretics work?
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Loop diurects like frusemide act upon the thick ascending loop (of Henle). They block the NaK2Cl channel, drawing these ions out plus Mg and Ca. Therefore there is a risk of metabolic alkalosis and depletion of minerals Mg/Ca.
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What are some side effects of loop diuretics?
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Side effects include metabolic alkalosis, hypokalaemia, dehydration, sulfur allergy, nephritis, gout.
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How and where do thiazides work?
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Thiazides work on the distal convuluted tubule, by inhibiting the Na/Cl channel. This tends to favor the reabsorption of Ca+ ions, which are drawn back here, and can lead to metabolic alkalosis
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Toxicity of thiazides includes?
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Hypokalaemic alkalosis, hyponatremia, Hyperglycemia, hyperlipidemia, hyperuremia, hypercalcemia. Sulfur allergy.
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Where and how does amiloride work?
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Amiloride acts upon the CCD, by blocking Na+ channels. Preventing sodium's reabsorption also prevents K+ loss (K-sparing), but can lead to risk of metabolic acidosis and hyperkalaemia.
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How does spironolactone work?
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Spironolactone antagonizes aldosterone receptors, thereby reducing Na+ channels and the Na/K pumps. This can lead to metabolic acidosis and hyperkalaemia, as with amiloride.
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What three molecules does the nephron use to modulate systemic pH?
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Bicarbonate (HCO-), which it can alter the reabsorption of, to raise systemic pH. H2PO4, which is can generate more of in the tubules, to lose more acid, and drop systemic pH. NH3 which it can also generate in the same fashion (proximal tubule)
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