Mineral Regulation- Weber

Question 1

what body fluid compartment is K+ high in

Answer 1

ICF

Question 2

____helps maintain transmembrane potential

Answer 2

K+

Question 3

_____ acts as a buffer and prevents large increases in K+ when the intake is large

Answer 3

Na+/K+ ATPase

Question 4

primary controller of ECF volume

Answer 4

Na+

Question 5

increase in K+ in ECF space

Answer 5

hyperkalemia

Question 6

decrease in K+ in ECF space

Answer 6

hypokalemia

Question 7

what is the main mechanism that moves K+ into the cell

Answer 7

Na+/K+ ATPase

Question 8

high level of H+ (into cell) exchanging for K+ (out of cell)

Answer 8

inorganic acidosis

Question 9

in cases of hypokalemia, what transporter flips to bring K+ out

Answer 9

H+/K+ cotransporter

Question 10

what does cell lysis cause

Answer 10

hyperkalemia

Question 11

during strenuous exercise, cell ATP depletion so what happens

Answer 11

increased K+ outside cell (hyperkalemia)

Question 12

what 2 things to use clinically to treat hyperkalemia

Answer 12

1. B2 agonists (stimulates ATPase)
2. insulin (stimulates ATPase)

Question 13

ECF hyperosmolarity causes what

Answer 13

hyperkalemia (K+ flows out of cell with water)

Question 14

ECF hyposmolarity causes what

Answer 14

hypokalemia (K+ stays in cell)

Question 15

where 60-70% of K+ reabsorption happens

Answer 15

PCT

Question 16

where 20% of K+ reabsorption happens

Answer 16

thick ascending limb

Question 17

in a low K+ diet, when it reaches late distal tubule what can happen

Answer 17

alpha intercalated cells reabsorb K+

Question 18

in a normal or high K+ diet, what happens at late distal tubule

Answer 18

principal cells cause K+ secretion

Question 19

fine tuning of K+ concentration here

Answer 19

collecting duct

Question 20

would I see K+ in my urine from my diet

Answer 20

not really due to variable secretion in late distal tubule

Question 21

when there is increased K+ in the serum what happens

Answer 21

hypothalamus releases aldosterone; K+ excretion

Question 22

range of K+ excretion

Answer 22

1-110%

Question 23

alpha intercalated cells K+ transporters

Answer 23

blood end: Na+/K+ ATPase
lumen end: H+/K+ cotransporter
and leak K+ channel

Question 24

what happens to K+ at alpha intercalated cells of late distal tubule and collecting duct

Answer 24

reabsorption

Question 25

K+ transporters of principal cells

Answer 25

blood end: Na+/K+ ATPase lumen end: ROMK (aldo stimulation)

Question 26

what happens at principal cells of late distal tubule and collecting duct

Answer 26

K+ secretion depending on Na+ absorption

Question 27

3 main factors contributing to K+ secretion

Answer 27

high K+ intake aldosterone tubular flow rate

Question 28

during K+ secretion, what side of cell has greatest concentration of K+; why?

Answer 28

lumen>serum; increased luminal fluid flow

Question 29

what is the result of alkalosis when H+ is lost to buffering (what happens to K+)

Answer 29

K+ uptake increases along with secretion result: hypokalemic metabolic alkalosis

Question 30

3 main organs dealing w/ Ca2+ homeostasis

Answer 30

gut bone kidney

Question 31

regulates Ca2+ absorption from diet

Answer 31

gut

Question 32

major depository of Ca2+ w/ buffering capacity

Answer 32

bone

Question 33

final arbiter of Ca2+ by excretion or conservation

Answer 33

kidney

Question 34

3 forms of circulating Ca2+

Answer 34

1. ion bound 2. protein bound 3. free or ionized

Question 35

active form of circulating Ca2+ that is the regulated component

Answer 35

free or ionized form

Question 36

regulators of Ca2+

Answer 36

PTH active vitamin D

Question 37

when there is low levels of Ca2+, what happens

Answer 37

PTH and active vitamin D activate

Question 38

what 3 responses happen to low Ca2+

Answer 38

increase in Ca2+ absorption in intestine and kidneys increase in Ca2+ release from bones

Question 39

where the free Ca2+ is filtered (60%)

Answer 39

glomerulus

Question 40

Ca2+ absorbed here in parallel to Na+

Answer 40

PCT

Question 41

Ca2+ coupled to Na+ absorption and passively moves to blood here

Answer 41

thick ascending limb

Question 42

Ca2+ absorption regulated by PTH here

Answer 42

DCT

Question 43

thiazides target this area and lead to Ca2+ reabsorption and decrease NaCl absorption

Answer 43

DCT

Question 44

cAMP dependent effect on active transport bringing Ca2+ into interstitium

Answer 44

PTH

Question 45

constituent of bone and urinary buffer for H+ excretion

Answer 45

phosphate

Question 46

PTH's effect on PCT

Answer 46

blocks Na+/phosphate cotransporter (brings both into cell) and causes their excretion

Question 47

maintaining ___ homeostasis is essential in chronic kidney disease

Answer 47

phosphate

Question 48

70% reabsorption of phosphate happens here

Answer 48

PCT

Question 49

stored in bone circulating form is protein bound cofactor for Na+/K+ ATPase (____ dependent)

Answer 49

Magnesium

Question 50

20-25% reabsorption of Mg here

Answer 50

PCT

Question 51

60% reabsorption of Mg here; coupled to Na+

Answer 51

thick ascending limb

Question 52

90% of uric acid reabsorbed where

Answer 52

PCT

Question 53

failure to clear uric acid

Answer 53

gout

Question 54

managing ______ is important in preventing stones

Answer 54

uric acid