Term
Describe what the RAAS system does in response to lowered blood pressure |
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Definition
1. BP drops 2. JG cells secrete renin 3. Renin acts on angiotensinogen to produce ANG I 4. ACE converts ANG I to ANG II 5. ANG II causes vasoconstriction 6. BP increases |
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Term
Low blood pressure can lead to ____ heart failure |
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Definition
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Term
Where does ACE come from? |
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Definition
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Term
Where does renin come from |
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Definition
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Term
Where does angiotensinogen come from |
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Definition
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Term
ANG II binds to an ____ receptor to promote vasoconstriction |
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Definition
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Term
Describe what the RAAS does in response to low blood volume |
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Definition
ANG II promotes aldosterone secretion from the adrenal cortex
ANG II & aldosterone tell kidneys to increase retention of salt & water
blood volume is increased |
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Term
______ leads to heart attacks |
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Definition
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Term
What would be prescribed to treat chronic high blood pressure? |
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Definition
ACE inhibitors, which prevent conversion of ANG I to ANG II |
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Term
Describe what happens with reabsorption |
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Definition
-Excess K+ in glomerular filtrate is returned to peritubular capillaries, reabsorbed in the PCT & descending loop of henle |
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Term
Where does resorption of salt & water occur? |
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Definition
65% in the peritubular capillaries of the PCT
20% through descending loop of henle |
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Term
Does reabsorption occur through PCT cells, or between them? |
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Definition
both!
leaky junctions between cells allows Na+ & K+ through (paracellular)
can also be transported through the cells (transcellular) |
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Term
_____ is the opposite of reabsorption |
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Definition
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Term
Is resorption passive or active? |
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Definition
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Term
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Definition
active transport of substances from peritubular capillaries into the tubular fluid |
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Term
What comes out in the descending loop of henle? What happens to osmolality? |
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Definition
water
increases from 300 to 800 to 1200 |
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Term
What comes out in the ascending loop of henle? What happens to osmolality? |
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Definition
various salts
decreases from 1200 to 700 to 200 |
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Term
What is the concentration of blood entering the glomerulus? |
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Definition
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Term
What happens in the ascending loop of Henle? |
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Definition
-salt is actively removed, to decrease osmolality from 1200 to 300 |
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Term
The ascending loop of Henle is rich in _____ |
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Definition
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Term
The ascending loop of henle is _____ to salt but _____ to water |
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Definition
permeable to salt impermeable to water |
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Term
Which has a thicker wall, the ascending or descending loop of henle? |
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Definition
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Term
What happens in the descending loop of henle? |
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Definition
-water is drawn out, so filtrate concentration increases from 300 to 1200 |
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Term
The descending loop of Henle is _____ to Na but _____ to water |
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Definition
impermeable to Na permeable to water |
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Term
What is the countercurrent multiplier system? |
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Definition
1. NaCl extruded from ascending limb, increases fluid concentration
2. Concentration effect is augmented by passive permeability of descending limb to water |
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Term
What happens in the collecting ducts? describe the steps |
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Definition
ADH promotes further removal of water from filtrate by osmosis
1. ADH binds to receptor 2. Signals via cAMP pathway 3. AQP2 inserted in apical side of mmb 4. H2O is absorbed by osmosis into the blood |
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Term
What must be present in order to make urine hyperosmotic (more concentrated than blood)? |
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Definition
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Term
Why doesn't water enter the interstitial fluid dilate the standing gradient? |
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Definition
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Term
What is the countercurrent exchange system? |
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Definition
Descending limb of vasa recta has lower solute concentration than the ascending limb
NaCl diffuses from ascending to descending limb, water from descending to ascending
Works in conjunction with loop of henle to take the water that is being removed & added |
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Term
What prevents backflow of urine from the bladder? |
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Definition
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Term
True or False
It is normal to find glucose in the urine |
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Definition
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