Term
| (04-27) What does GFR stand for? |
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Definition
| Glomerular filtration rate |
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Term
| (04-27) Define filtered load. |
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Definition
| The amount of solute (load) removed from plasma |
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Term
| (04-27) What is the equaion for clearance? |
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Definition
| (([x]urine)(urine production rate))/([x]plasma]) |
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Term
| (04-27) If a substance x is freely filtered and is not secreted or reabsorbed, then clearance of that substance equals ____. |
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Definition
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Term
| (04-27) What are the molecules that are freely filtered but not secreted nor absorbed? |
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Definition
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Term
| (04-27) What is the clearance of inulin? Why? |
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Definition
| The clearance is equal to the glomerular filtration rate because it is not secreted or reabsorbed |
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Term
| (04-27) What’s special about para-aminohippuric acid (PAH)? What is it used for? |
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Definition
| It is freely filtered but not reabsorbed; it is completely secreted. It is used to find renal plasma flow (Clearance of PAH = Renal plasma flow) |
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Term
| (04-27) If 20% of PAH is filtered, how much PAH is secreted? |
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Definition
| 80% is secreted; plasma is completely cleared of PAH |
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Term
| (04-27) You find the clearance of PAH to be 100 mL/min. What is the renal plasma flow? How much PAH was fitered? How much PAH was secreted? |
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Definition
| RPF = 100 mL/min; 20 mL filtered; 80 mL secreted |
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Term
| (04-27) What information from a blood sample is needed to calculate renal blood flow? What’s the formula using this information? |
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Definition
| Hematocrit; Renal blood flow = (Renal plasma flow)/(1-hematocrit) |
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Term
| (04-27) Define reabsorption. |
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Definition
| The movement of solutes and water from lumen of tubules back into plasma |
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Term
| (04-27) Where does (most) reabsorption take place? |
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Definition
| The proximal and distal tubules (70% of water and salt reabsorption appens in the proximal tubule) |
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Term
| (04-27) What inhibits the movement of reabsorption? |
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Definition
| The apical and basolateral membranes of the tubular epitelium are the main barriers to movement |
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Term
| (04-27) Which way does the kidney apical membrane face? |
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Definition
| Toward the lumen of the kidney |
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Term
| (04-27) What are the three types of reabsorption? |
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Definition
| Active solute transport, passive water movement, passive solute movement |
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Term
| (04-27) What is active solute transport reabsorption? |
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Definition
| Reabsorption that requires transporters or channels on the apical or baasolateral membranes |
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Term
| (04-27) What is passive water movement reabsorption? |
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Definition
| Reabsorption that requires an increase in plasma osmolarity |
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Term
| (04-27) What ion is key for the movement of solutes in the kidney? |
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Definition
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Term
| (04-27) Why does the kidney use so much ATP? |
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Definition
| It has to constantly power the sodium/potassium pump |
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Term
| (04-27) On a graph of plasma concentration (x-axis) vs. rate of glucose movement (y-axis), what is the slope of filtration? |
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Definition
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Term
| (04-27) On a graph of plasma concentration (x-axis) vs. rate of glucose movement (y-axis), what is the slope of reabsorption? |
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Definition
| Positive slope, extending ino a plateau |
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Term
| (04-27) To what extent is glucose filtered? Reabsorbed? Secreted? |
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Definition
| Freely filtered, normally completely reabsorbed, never secreted |
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Term
| (04-27) What happens when the kidney’s capacity to reabsorb a substance is exceeded? |
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Definition
| The substance is excreted |
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Term
| (04-27) With an increase in glucose, you ______ the amount of glucose filtered. |
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Definition
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Term
| (04-27) With a small increase in glucose, you ______ the amount of glucose reabsorbed. |
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Definition
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Term
| (04-27) With a substantial increase in glucose, you _______ the amount of glucose reabsorbed. |
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Definition
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Term
| (04-27) When you max out the body’s capacity to reabsorb glucose, what happens to the excess? |
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Definition
| It is excreted through urine |
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Term
| (04-27) Define transport maximum. |
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Definition
| The point in time when all transporters for a sustance are saturated (“occupied”) |
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Term
| (04-27) Define renal threshold. |
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Definition
| The plasma concentration at which the solute shows up in urine |
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Term
| (04-27) On a graph of plasma concentration of glucose (x-axis) vs. rate of glucose movement (y-axis), what marks the transport maximum? |
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Definition
| The plateau of the reabsorption curve |
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Term
| (04-27) For diabetics, the filtered load of glucose is _____ than the transport maximum of glucose. |
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Definition
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Term
| (04-27) What is the difference between reabsorption and secretion? |
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Definition
| The direction of steps; reabsorption is in, secretion is out. |
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Term
| (04-27) What are the two main equations for excreted load? |
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Definition
| EL = (concentration of substance in urine)(rate of urine production) or EL = (filtered load) – (reabsorbed load) – (secreted load) |
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