fong VIII

Question 1

how much Ca2+ is filtered at the glomerulus?

Answer 1

~60%

Question 2

do the kidneys secrete Ca2+?

Answer 2

no

Question 3

how is calcium absorbed in the proximal tubules?

Answer 3

passive, paracellular

Question 4

how is calcium absorbed in the distal tubules?

Answer 4

transcellular

Question 5

what regulates calcium at the level of the bone and kidney?

Answer 5

PTH

Question 6

1, 25 dihroxvitamin D stimulates what?

Answer 6

intestinal Ca2+ uptake

Question 7

Thiazide diuretics to what to DT Ca2+ absorption?

Answer 7

enhance it

Question 8

resting membrane potential, Vm, is determined largely by what?

Answer 8

membrane K+ conductance

Question 9

what happens when K+ is in excess?

Answer 9

K+ is excreted

Question 10

what 2 things happen in acute regulation of K+ in ECF?

Answer 10

• uptake into ICF (Na+/K+ ATPase)

- skeletal muscle is a major reservoir

Question 11

what 2 things happen in long term regulation of ECF K+?

Answer 11

• fecal loss

- renal excretion

Question 12

most of the K+ in the body resides where?

Answer 12

in the intracellular space

Question 13

what cells secrete K+ in the CD?

Answer 13

principle cells

Question 14

K+ is inhibited by what?

Answer 14

acidosis

Question 15

K+ is stimulated by what?

Answer 15

alkalosis

Question 16

T/F: aldosterone stimulates ROMK.

Answer 16

true

Question 17

at a low K+ load:

Answer 17

ROMK is sequestered

BK is closed

Question 18

at a modest K+ load:

Answer 18

ROMK is open

BK is closed

Question 19

at a high K+ load:

Answer 19

ROMK is open

BK is open

Question 20

how are BK channels regulated?

Answer 20

by flow

Question 21

acidic ECF = hyper or hypo kalemia

Answer 21

hyperkalemia

-acidic inhibits ROMK

Question 22

alkaline ECF = hyper or hypo kalemia

Answer 22

hypokalemia

-alkaline actives ROMK