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Renal 2
Dr. P-Test 1
31
Physiology
Graduate
11/27/2010

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Cards

Term
Uncontrolled reabsorption occurs where?
Definition
Proximal tubules
Term
Controlled reabsorption occurs where?
Definition
distal tubules & collecting ducts
Term
What causes high permeability of capillaries in glomerulus?
Definition
fenestrations
Term
Of the following, which does not belong in the filtrate? (normally)
water, sugars, wastes, proteins, salts, amino acids
Definition
proteins
Term
average amount of urine produced in a day?
Definition
1-1.5 liters
Term
What do podocytes do?
Definition
prevent plasma proteins from getting into the filtrate
Term
What do macula densa cells do and where are they located?
Definition
sense salt delivery and filtration rate
distal tubule
Term
What do juxtaglomerular cells do?
Definition
produce renin
Term
what are mesangial cells?
Definition
they contain actin and myosin (for contraction)
Term
what is the cause of high pressure in the glomerulus?
Definition
the afferent arteriole is bigger than the efferent arteriole, so blood collects in the glomerulus and builds pressure
Term
What are the three lines of defense for plasma proteins?
Definition
capillary pores, negatively charged basement membrane, podocytes
Term
what is the value of net filtration pressure?
Definition
10 mmHg
Term
3 types of pressure that factor in to net filtration pressure
Definition
glomerular blood pressure (favors movement toward filtrate)
plasma osmotic pressure (favors movement toward blood)
Bowman's Capsule Hydrostatic Pressure (movement toward blood)
Term
what factor is GFR dependent on?
Definition
net filtration pressure (glomerular surface area and permeability remain constant)
Term
when there is increased pressure and the arteriole becomes stretched, what does the smooth muscle do?
Definition
the smooth muscle contracts to limit blood flow and maintains GFR
Term
what is the juxtaglomerular apparatus?
Definition
distal tubules and afferent arteriole
Term
If there is a high salt flow in the distal tubule, what is also higher that normal?
What is the response?
Definition
high GFR
macula densa cells release adenosine, which constricts the afferent arteriole and lowers GFR
Term
what causes a decrease in GFR?
Definition
dehydration, hemorrhaging, etc (hypovolumetric states)
Term
what causes an increase in GFR?
Definition
high protein diet, pregnancy, increased plasma volume
Term
how are glucose and amino acids reabsorbed?
Definition
secondary active transport
Term
at the lumenal/apical membrane, what mechanism is used for glucose reabsorption? what does glucose reabsorption depend on?
Definition
SGLT
sodium
Term
what transports glucose out the basolateral side into the blood?
Definition
GLUT
Term
what is the tubular maximum for glucose?
Definition
375 mg/min
Term
what happens if the amount of glucose filtered per minute is more than the tubular maxium?
Definition
the extra glucose remains in the filtrate
Term
after a lot of reasorption of nutrients/salts in the proximal tubule, what happens to urea?
Definition
passive reabsorption of urea due to concentration gradient
Term
where is urea secreted?
Definition
this ascending and descending limbs
Term
how are foreign substances secreted?
Definition
liver converts them to an anionic metabolite, and is secreted in the PCT through anionic carriers
Term
where does aldosterone act?
Definition
cortical collecting tubule
Term
where does vasopressin act?
Definition
outer and inner medullary collecting ducts
Term
what part of the loop of henle is permeable to water?
Definition
descending
Term
how is salt transported out of the lumen of the thick ascending limb?
Definition
secondary active transport (Na-K-2Cl cotransporter) and primary active transport (Na-K-ATPase in basolateral membrane)
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