Term
| Uncontrolled reabsorption occurs where? |
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Definition
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Term
| Controlled reabsorption occurs where? |
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Definition
| distal tubules & collecting ducts |
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Term
| What causes high permeability of capillaries in glomerulus? |
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Definition
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Term
Of the following, which does not belong in the filtrate? (normally)
water, sugars, wastes, proteins, salts, amino acids |
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Definition
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Term
| average amount of urine produced in a day? |
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Definition
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Term
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Definition
| prevent plasma proteins from getting into the filtrate |
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Term
| What do macula densa cells do and where are they located? |
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Definition
sense salt delivery and filtration rate
distal tubule |
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Term
| What do juxtaglomerular cells do? |
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Definition
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Term
| what are mesangial cells? |
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Definition
| they contain actin and myosin (for contraction) |
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Term
| what is the cause of high pressure in the glomerulus? |
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Definition
| the afferent arteriole is bigger than the efferent arteriole, so blood collects in the glomerulus and builds pressure |
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Term
| What are the three lines of defense for plasma proteins? |
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Definition
| capillary pores, negatively charged basement membrane, podocytes |
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Term
| what is the value of net filtration pressure? |
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Definition
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Term
| 3 types of pressure that factor in to net filtration pressure |
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Definition
glomerular blood pressure (favors movement toward filtrate)
plasma osmotic pressure (favors movement toward blood)
Bowman's Capsule Hydrostatic Pressure (movement toward blood) |
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Term
| what factor is GFR dependent on? |
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Definition
| net filtration pressure (glomerular surface area and permeability remain constant) |
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Term
| when there is increased pressure and the arteriole becomes stretched, what does the smooth muscle do? |
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Definition
| the smooth muscle contracts to limit blood flow and maintains GFR |
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Term
| what is the juxtaglomerular apparatus? |
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Definition
| distal tubules and afferent arteriole |
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Term
If there is a high salt flow in the distal tubule, what is also higher that normal?
What is the response? |
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Definition
high GFR
macula densa cells release adenosine, which constricts the afferent arteriole and lowers GFR |
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Term
| what causes a decrease in GFR? |
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Definition
| dehydration, hemorrhaging, etc (hypovolumetric states) |
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Term
| what causes an increase in GFR? |
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Definition
| high protein diet, pregnancy, increased plasma volume |
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Term
| how are glucose and amino acids reabsorbed? |
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Definition
| secondary active transport |
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Term
| at the lumenal/apical membrane, what mechanism is used for glucose reabsorption? what does glucose reabsorption depend on? |
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Definition
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Term
| what transports glucose out the basolateral side into the blood? |
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Definition
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Term
| what is the tubular maximum for glucose? |
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Definition
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Term
| what happens if the amount of glucose filtered per minute is more than the tubular maxium? |
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Definition
| the extra glucose remains in the filtrate |
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Term
| after a lot of reasorption of nutrients/salts in the proximal tubule, what happens to urea? |
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Definition
| passive reabsorption of urea due to concentration gradient |
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Term
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Definition
| this ascending and descending limbs |
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Term
| how are foreign substances secreted? |
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Definition
| liver converts them to an anionic metabolite, and is secreted in the PCT through anionic carriers |
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Term
| where does aldosterone act? |
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Definition
| cortical collecting tubule |
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Term
| where does vasopressin act? |
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Definition
| outer and inner medullary collecting ducts |
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Term
| what part of the loop of henle is permeable to water? |
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Definition
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Term
| how is salt transported out of the lumen of the thick ascending limb? |
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Definition
| secondary active transport (Na-K-2Cl cotransporter) and primary active transport (Na-K-ATPase in basolateral membrane) |
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