Term
What is the equation for renal plasma flow (RPF)?
What is the normal RPF value? |
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Definition
RPF = RBF x (1-HCT)
RPF = 625 ml/min |
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Term
What is the equation for glomerular filtration rate (GFR)?
What is the normal GFR value? |
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Definition
GFR = FF x RPF
GFR = .20 x 625 ml/min
GFR = 125 ml/min |
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Term
| What is the blood pressure in the glomerular capillaries? peritubular capillaries? |
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Definition
glomerular capillaries = 60 mmHg
peritubular capillaries = 20 mmHg |
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Term
| where is the greatest fall in pressure in renal vasculature? |
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Definition
| afferent and efferent arterioles |
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Term
| what is the difference in sympathetic inputs between afferent and efferent arterioles? |
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Definition
| afferent arterioles have 10x the sympathetic inputs as efferent arterioles |
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Term
| why is glomerular filtrate called an ultrafiltrate? |
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Definition
| it is an exact replica of the blood plasma except that it lacks RBCs, WBCs, and large plasma proteins |
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Term
| what is the filtration coefficient Kf similar to in the lung? |
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Definition
| DLO2 (diffusion coefficient) |
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Term
| How do you calculate GFR from the filtration coefficient and Starling forces? |
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Definition
| GFR = Kf x (PGC + πBS – PBS – πGC) |
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Term
| What is the net pressure (hydraulic and oncotic) on the afferent end of the glomerular capillaries? on the efferent end? |
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Definition
afferent end = +24 mmHg
efferent end = +10 mmHg |
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Term
| what is the oncotic pressure of Bowman's space? |
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Definition
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Term
| what Starling force affects the net pressure the most from the afferent to the efferent ends? |
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Definition
| oncotic pressure in the glomerular capillary (it increases from 21 to 33 mmHg from afferent to efferent) |
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Term
| what would happen to GFR in liver failure?? |
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Definition
| liver failure causes a decrease in albumin production which would decrease pi oncotic pressures in the glomerular capillaries resulting in INCREASED filtration |
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Term
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Definition
| single nephron glomerular filtration rate -- each nephron has its own GFR controlled by its JGA |
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Term
| over what range of arterial pressures are renal blood flow, renal plasma flow and glomerular filtration rate regulated? |
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Definition
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Term
| at what low pressure does the kidney shutdown and not produce urine? (as in hypovolumic shock) |
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Definition
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