Term
| In what arterial pressure range are both GFR and RBF maintained? |
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Definition
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Term
| What are two intrinsic mechanisms of autoregulation? |
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Definition
Myogenic mechanism
Tubuloglomerular feedback |
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Term
| Define myogenic mechanism? |
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Definition
| the changes in pressure in the arterioles causes the smooth muscles to stretch which stimulates them to contract. |
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Term
| What is the receptor and stimulus of the tubuloglomerular feedback mechanism? |
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Definition
The receptor is the macula densa.
The stimulus is an increase in NaCl delivery to the macula densa or an increase in tubular fluid flow rate. Either of these cause a fall in GFR. |
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Term
| What are the requirements of a substance being used to measure glomerular filtration rate? |
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Definition
-must pass freely from glomerular capillaries into filtrate
-must be neutrally charges
-must not bind to plasma proteins
-must not be secreted
-must not be reabsorbed
-all that is filtered must be secreted |
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Term
| What substance is used to glomerular filtration rate? |
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Definition
| Inulin is infused IV to measure GFR. |
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Term
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Definition
| The volume of plasma from which all of a substance has been removed and excreted into urine per unit of time. |
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Term
| T/F. Inulin clearance is dependent on plasma inulin concentration and urine flow. |
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Definition
| False. Inulin clearance is independent of plasma inulin concentration and urine flow. |
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Term
| What endogenous substance approximates GFR? |
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Definition
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Term
| What can creatine be an approximation of? |
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Definition
| Plasma creatine levels can be an approximation of GFR |
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Term
| If the amount of inulin filtered into the tubule does not change then what would changes in concentration of inulin reflect? |
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Definition
| Changes in water movement. |
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Term
| What is fractional excretion? |
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Definition
| Fractional excretion shows the fraction of the filtered mass of a substance that was excreted. |
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Term
| How is fractional excretion found? |
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Definition
| Mass excreted divided by mass filtered |
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