Term
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Definition
| movement of substances from tubules into peritubular capillaries (returned to blood) |
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Term
| Where does most reabsorption occur? |
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Definition
| proximal convoluted tubule, some in distal tubule |
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Term
| What is the barrier for reabsorption? |
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Definition
| epithelial cells of renal tubules and endothelial cells of capillary |
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Term
| solute and water reabsorption depends on- |
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Definition
| transport proteins and membrane permeability to water |
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Term
| Molecules reabsorbed in the proximal convoluted Tubule include: |
|
Definition
| glucose, amino acids (both 100% absorbed) sodium, urea, water |
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Term
| Aprox how much filtered water is reabsorbed in PCT? and why? |
|
Definition
| 65%, due to osmotic gradient produced by the reabsorption of solute. |
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Term
| Glucose and amino acids are co-transported with-- into PCT cells |
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Definition
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|
Term
| The transporters can be -- meaning that above a certain filrate concentration no further reabsorption occurs and the remainder is-- |
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Definition
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Term
| Is there normally glucose in the urine? |
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Definition
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|
Term
| During diabetes mellitus- |
|
Definition
| plasma glucose can be as high as 600 mg/100mL which exceeds Tmax (transportation maximum) |
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Term
|
Definition
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Term
|
Definition
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Term
| descending loop of henle- |
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Definition
| water reabsorption, 15%, little solute reabsopbed= concentrates the fluid in tubule |
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|
Term
ascending loop of henle-
thin portion of loop-
thick- |
|
Definition
sodium and chloride reabsoption.
passive sodium channels
secondary active transporter |
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|
Term
| Distal Convoluted Tubule (DCT) |
|
Definition
regulates sodium reabsorption
depends on aldosterone secreted by adrenal cortex cells.
Part of RAAS (renal, angiotensin, aldosterone system) |
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Term
|
Definition
| hormone secreated by kidney in response to low plasma sodium or low plasma and ECF volume |
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Term
|
Definition
| increases sodium reabsorption from DCT |
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Term
|
Definition
| water reabsorption (some sodium) |
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Term
| water reabsorption in DCT depends on |
|
Definition
| anti diuretic hormone (ADH, vasopressin) |
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Term
|
Definition
| water channels (aquaporins) into membrane, allows water to move from tubule to cells. Without water can't pass membranes |
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Term
| ADH is produced in , released from |
|
Definition
| hypothalamus, posterior pituitary gland |
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Term
| ADH is secreated in response to |
|
Definition
| low ECF volume (allows water to be reabsored to increase volume) or increased ECF osmolarity |
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Term
|
Definition
| water remains in tubules are is lost in urine |
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Term
|
Definition
| solute moves from peritubular capillaries into tubules |
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Term
|
Definition
| potassium, H+ ions, penicillin |
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Term
| To maintain water balance over time: |
|
Definition
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Term
|
Definition
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Term
|
Definition
| high blood volume due to positive water balance |
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Term
|
Definition
| low blood volume due to negative water balance |
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Term
| Concentrated v. dilute urine |
|
Definition
A lot of urine- dilute,
small amount- concentrated to conserve water |
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Term
|
Definition
| water moves down concentration gradient, |
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|
Term
Proximal tubules reabsorb -
(regulated?) |
|
Definition
| 70% filtered water and is not regulated |
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|
Term
Desending loop of henle reabsorb-
(regulated) |
|
Definition
| 15% of filtered water, not regulated |
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|
Term
Distal tubules and collecting ducts reabsorb-
(regulated?) |
|
Definition
| most remaining water, regulated by ADH |
|
|
Term
| what gradient is critical for water reabsorption? |
|
Definition
| medullary osmotic gradient |
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|
Term
| what is the osmotic gradient established by in the loop of henle- |
|
Definition
counter current multiplier
descending is permeable to water but not Na, Cl, or K.
Ascending limb isn't permemable to water but is active transport for Na, Cl, K |
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Term
| filtrate is (more or less) dilute at top of ascending limb? |
|
Definition
| More b/c of active transport of Na Cl K |
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|
Term
| The -- in interstitial fluid favors reabsorption of water from tubules |
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Definition
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|
Term
| In distal tubules and collecting ducts water permeability depends on - |
|
Definition
| aquaporin-2 present in apical membrane only when ADH is present |
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Term
| How is the urine with the presence of ADH? |
|
Definition
| small vol and concentrated |
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Term
| How is the urine without the presence of ADH? |
|
Definition
| no water reabsorption=water is excreted |
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