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Cards In This Set
| Front | Back |
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Urea
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N -> ammonium -> ammonia -> urea
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Urinary System Function
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Excrete waste
regulateblood vol/BPsolute concentrationRBC/Vit D sythesispH of extracellualar fluid |
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Nephrons
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JuxatmedullaryCortical
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Capillary Beds
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Glomerulus (FILTRATION)
Peritubular/ Vasa Recta (REABSORBTION AND SECRETION) |
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Bowerman's capsule
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Parietal LumenVisceral (w/ podocytes)
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Filtration Membrane
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fenestrated Glomerular capillaries (larger than)-> podocytes: filration slits
allow protein free, solute rich fluid into capsule |
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Filration
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High BP
Very permeable filtration membrane |
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Glomular Filtration Rate
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180L/day
if too high -> can't reabsorb if too low -> everything reabsorbed |
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Net Filration Pressure
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Glomular BP - (Blood Colloid Osmotic P + Capsular BP) = 10
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GFR Regulation
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Neural/ Hormonal / Intrinsic
Autoregulation (Intrinsic) = myogenic^ BP -> stretched wall -> contract vessels -> reduce BP |
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Intrinsic GFR Regulation
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myogenic^ BP -> stretched wall -> contract vessels -> reduce BP
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Extrinsic GFR Regulation
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Usual = sympathetic at rest - dilated vessels
stress -> SNS and arenal medulla -> norep and ep -> constrict afferent arterioles -> inhibit filtration |
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Reabsorption
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PCT
Substances from tubule lumen -> tubule basolateral membrane -> peritubular cap's endothelium (paracellular or transcellular) all organic compounds reclaimed by end of PCT |
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Sodium Reabsorption
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Active transport via Na/K pump
carries other solutes into tubule cell -> solutes leave basomembrane by diffusion -> interstitial fluid Drive water by osmosis (via aquaporines)ions and fat-solubles via diffusion limited by Transport Max |
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Transport Max
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When carriers for each substance's active transport our of filtrate is saturated -> excess secreted
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