Disorders of K+ Metabolism- Bessette

Question 1

_____ is found intracellular and mainly in muscles

Answer 1

K+

Question 2

2 mechanisms of K+ balance:

Answer 2

transcellular shifts
regulation from kidneys and intestines

Question 3

freely filtered and then reabsorbed in PCT and loop of henle

Answer 3

K+

Question 4

distal delivery of Na+ and water, and MR activity determine what

Answer 4

K+ secretion

Question 5

65-70% K+ reabsorbed here

Answer 5

PCT

Question 6

driven by concentration gradient initiated by Na+ and H2O

Answer 6

K+ reabsorption in PCT

Question 7

2 transporters of TAL that K+ is involved in

Answer 7

NKCC2
ROMK

Question 8

fine tuning of K+ homeostasis starts here

Answer 8

early DCT

Question 9

what 2 transporters of early DCT provide basis of transport for Na+, Cl-, Ca2+, and Mg2+ into and out of lumen

Answer 9

NCC
Na+/K+ ATPase

Question 10

increased plasma [K+] does what to NCC activity

Answer 10

decreases it

Question 11

decreased plasma [K+] does what to NCC activity

Answer 11

increases it

Question 12

these cells reabsorb Na+ (ENaC) and water and secrete K+ through ROMK

Answer 12

principal cells

Question 13

these cells secrete H+ and reabsorb K+ and HCO3-

Answer 13

alpha intercalating cells (respond to acidosis)

Question 14

if lumen [K+] is high, what happens to K+

Answer 14

more will be reabsorbed

Question 15

if intracellular [K+] is high, what happens

Answer 15

more K+ secretion and decreased absorption

Question 16

ENaC brings Na+ in, more - on lumen side, what happens to K+

Answer 16

secreted into lumen

Question 17

more water flow, more flush out, more ______ goes out

Answer 17

K+

Question 18

why can a patient on ARBs experience hyperkalemia

Answer 18

aldosterone not binding to MR; less K+ being secreted through ROMK

Question 19

RAAS disruption can cause what to K+

Answer 19

hyperkalemia

Question 20

binds MR; increases # of ENaC channels
increases ROMK channels
activates Na+/K+ ATPase

Answer 20

Aldosterone

Question 21

secrete HCO3- and K+; H+ reabsorption

Answer 21

beta intercalated cells (responding to alkalosis)

Question 22

secrete H+; reabsorb HCO3- and K+

Answer 22

alpha intercalated cells (in response to acidosis)

Question 23

what happens in a low K+ diet

Answer 23

body wants to secrete less of K+
(more reabsorption of K+)

Question 24

in a high K+ diet what happens

Answer 24

intercalated cells increase K+ secretion
aldosterone increased; more K+ secretion (principal cells)

Question 25

ability of the kidney to stimulate NaCl retention w/ minimal K+ secretion during hypovolemia

Answer 25

aldosterone paradox

Question 26

ability of kidney to maximize K+ secretion without Na+ retention in hyperkalemia

Answer 26

aldosterone paradox

Question 27

what happens at alpha intercalated cells in response to acidosis

Answer 27

H+ secreted; HCO3- and K+ reabsorbed

Question 28

what happens at beta intercalated cells during alkalosis

Answer 28

secrete HCO3- and K+ and reabsorb H+

Question 29

what controls extra-renal K+ homeostasis

Answer 29

insulin and catecholamines

Question 30

what does insulin do to K+

Answer 30

stimulates Na+/K+ ATPase and puts K+ into cell

Question 31

what happens in patient after K+ containing meal who has uncontrolled diabetes type 1 and doesn't have insulin

Answer 31

increase in extracellular K+ (hyperkalemia) b/c no insulin to bring it into cell

Question 32

____-adrenergic receptors impair cellular entry of K+ into cells

Answer 32

alpha

Question 33

____-adrenergic receptors promote cellular entry of K+ into cells

Answer 33

beta

Question 34

beta 2 adrenergic receptor agonist

Answer 34

Albuterol

Question 35

_____ released during exercise limits amount of K+ in interstitial space

Answer 35

catecholamines

Question 36

_____ moves K+ to interstitial space in skeletal muscle

Answer 36

exercise

Question 37

______when [H+] in blood decreases; H+ leaves cell into blood and K+ enters cell

Answer 37

alkalemia

Question 38

_____when [H+] in blood increases; H+ moves into cell and K+ leaves cell into blood

Answer 38

acidemia

Question 39

mineral acidosis of skeletal muscle causes what to happen to K+

Answer 39

increase in serum [K+]

Question 40

organic acidosis of skeletal muscle causes what to happen to K+

Answer 40

no change in serum [K+]

Question 41

hyper-osmolarity of ECF space causes what to happen to water and K+

Answer 41

water flows into space and brings K+ with it; cell shrinkage (movement out of cell into ECF space)

Question 42

patient with this disease has a hard time handling K+

Answer 42

chronic kidney disease

Question 43

increase in K+ intake=_______ bp

Answer 43

lower bp

Question 44

K+ deficiency (less ROMK channels); more ____ reabsorption and higher bp

Answer 44

Na+

Question 45

all interrupt RAAS and lead to less K+ secretion (causing hyperkalemia)

Answer 45

ACEIs/ARBs and NSAIDs

Question 46

these 2 things lead to hypokalemia (deals with aldosterone---hint)

Answer 46

primary and secondary aldosteronism

Question 47

K+ loss or low intake or intracellular shift of K+

Answer 47

hypokalemia

Question 48

3 main causes of hypokalemia

Answer 48

cellular shifts GI loss urinary K wasting

Question 49

alkalosis insulin beta agonist hyperaldosteronism

Answer 49

lead to hypokalemia

Question 50

vomiting and diarrhea lead to what

Answer 50

hypokalemia

Question 51

diuretics Bartter syndrome Gitelman syndrome

Answer 51

lead to hypokalemia

Question 52

weakness, fatigue, confusion, alkalosis

Answer 52

hypokalemia

Question 53

high U wave on ECG

Answer 53

hypokalemia

Question 54

3 main causes of hyperkalemia

Answer 54

cellular shifts increased intake less K+ excretion

Question 55

extra renal metabolic acidosis causes what to happen to K+

Answer 55

H+ from blood into cell and K+ out of cell into blood (hyperkalemia)

Question 56

muscle twitches, cramps, abd cramping

Answer 56

hyperkalemia

Question 57

peaked T wave on ECG P wave flattening PR elongation Wide QRS’s

Answer 57

hyperkalemia

Question 58

seen in patients with leukocytosis or thrombocytosis; falsely elevated K+ in serum

Answer 58

pseudohyperkalemia

Question 59

elevates serum K+ but no plasma K+ (pseudohyperkalemia)

Answer 59

thrombocytosis

Question 60

insulin aldosterone dietary restriction

Answer 60

treat hyperkalemia

Question 61

CKD increases RAAS (and vice versa CKD can lead to HTN and HTN can lead to CKD) and what happens to K+

Answer 61

more aldosterone and more K+ secretion

Question 62

how does diabetic nephropathy lead to hyperkalemia

Answer 62

no/dysfunctional insulin unable to bring K+ into cells; and also damage to kidney function being able to secrete K+; and hyperglycemia causes water and K+ to flow into blood