Term
| what is the definition of renal clearance? |
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Definition
| the volume of plasma per minute from which all of any substance (X) is removed from the blood into the urine |
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Term
| what units does clearance have? |
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Definition
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Term
| What is the equation for clearance? |
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Definition
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Term
| What three tests do you need to calculate the clearance of any substance? |
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Definition
| arterial blood sample, a urine sample, and a urine flow rate |
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Term
| What changes in the F + S = R + E equation for inulin? |
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Definition
| it becomes F = E because inulin is neither secreted nor reabsorbed |
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Term
| What is the clearance of inulin equal to? |
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Definition
| clearance of inulin = GFR |
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Term
| What is GFR comparable to in the lungs? |
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Definition
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Term
| what does it mean if C(X) > C(inulin)? |
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Definition
| the substance X must also be secreted in addition to being filtered |
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Term
| what does it mean if C(X) < C(inulin)? |
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Definition
| the substance X, if filtered, must also be reabsorbed from the tubules |
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Term
| what exogenous organic anion is 90% cleared from the blood on a single pass through the kidneys? |
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Definition
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Term
| what equations do we use when estimating effective renal plasma flow with PAH? |
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Definition
ERPF = CPAH = UPAH x Vdot/PPAH
RPF = 1.1 x EPRF
RBF = RPF/(1-HCT) |
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Term
| what endogenous substance is a good substitute for inulin? |
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Definition
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Term
| how is creatinine produced in the body? |
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Definition
| it is a product of muscle metabolism |
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Term
| how is plasma creatinine a detector of renal failure? |
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Definition
| high levels of plasma creatinine suggest low GFR |
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Term
| what is normal GFR and PCr? how do you calculate the load of creatinine from the two? |
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Definition
GFR = 180 L/day (125 ml/min)
PCr = 1mg/100mL
GFR x PCr = LoadCr
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Term
| how is urea produced in the body? |
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Definition
| it is a metabolic product of protein catabolism |
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Term
| what is the relationship between BUN and creatinine concentrations in the blood? |
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Definition
| BUN concentrations are normally 10x higher than creatinine |
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Term
| what are urea concentrations a reflection of? what are creatinine concentrations a reflection of? which is less stable? |
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Definition
[urea] is a reflection of proteins meals [creatinine] is a reflection of body mass
urea is much less stable over time |
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