From Boron and web notes

Question 0

where does metabolism of vitamin D occur in the kidney

Answer 0

3rd hydroxylation occurs in the proximal tubule

Question 1

3 actions of SNS in the kidney

Answer 1

• vasoconstriction of afferent arteriole
• enhance Na reabsorption in PCT
• increases renin secretion by stimulating granular cells of afferent arteriole

Question 2

what is the action of active metabolite of vitamin D

Answer 2

controls calcium and phosphate metabolism by acting on intestines, kidneys and bone

Question 3

when is EPO secreted from the kidney

Answer 3

in response to fall in local tissue pO2

Question 4

which prostaglandin does the kidney secrete

Answer 4

prostacyclin

Question 5

urine clearance equations (in words)

Answer 5

the conc of substance in urine x urine flow / plasma conc of substance

Question 6

normal glomerular filtration rate

Answer 6

180L/day or 125ml/min

Question 7

what is autoregulation in the kidney

Answer 7

when high renal artery pressure there is a proportional increase in the resistance of the afferent arterioles
(caused by the myogenic response and TGF)

Question 8

what is the role of the macula densa in Tubuloglomerular feedback

Answer 8

senses increased Na and Cl due to increased flow through the kidney and therefore increased GFR. Releases particularly ATP, adenosine and thromboxane to act on the afferent arteriole to constrict –> decreasing GFR

Question 9

what is the action of angiotensin II on the:

• afferent arteriole
• efferent arteriole
• TGF mechanism

Answer 9

afferent - constriction
efferent - constriction
TGF - increased sensitivity

Question 10

how is urea made

Answer 10

generated from end product of amino acid catabolsim NH4+ in the liver

Question 11

normal reabsorption of phosphate

Answer 11

PT absorbs 80%
DT absorbs 10%
(excrete 10%)

Question 12

how is phosphate reabsorbed

Answer 12

mostly by transcellular route

some through active transport coupled with Na

Question 13

action of PTH on phosphate and calcium reabsorption

Answer 13

inhibits phosphate reabsorption –> promoting excretion

promotes calcium reabsorption –> decreasing excretion

Question 14

what is the most conc urine that we can produce? and what is the minimum volume of urine that this can be dissolved in

Answer 14

1200mOsm - minimum of 500mL per day

Question 15

how much of the CO is at the kidneys

Answer 15

20%

Question 16

where is the SNS supply greatest? to the afferent or efferent arteriole

Answer 16

afferent

Question 17

what is the result of SNS stimulation on the kidney

Answer 17

raises BP by vasoconstriction of the whole body arterioles and by decreasing GFR by vasoconstriction of afferent arterioles (and therefore decreased Na and H20 excretion –> maintaining BV and therefore BP)