Renal Acid/Base

Question 1

HCO3- reabsorption

Answer 1

99.9%

Question 2

ESRD effects

Answer 2

decr plasma HCO3-
incr plasma K+
incr BP
decr Hct
incr Po4-

Question 3

what typically triggers dialysis

Answer 3

high K+

Question 4

why does Hct decreases in ESRD

Answer 4

decr EPO production

Question 5

why does Po4- increase in ESRD

Answer 5

kidney is primary route of PO4- excretion

Question 6

vital pH limits

Answer 6

6.8-7.8

Question 7

how do we lower volatile acid

Answer 7

expiration

Question 8

how much volatile acid do we produce

Answer 8

15,000 mEq /day

Question 9

how much non volatile acid do we produce

Answer 9

70 mEq/day

Question 10

how do we remove non volatile acid

Answer 10

secreted/excreted by kidney

Question 11

foods that cause alkalosis

Answer 11

fruit
veg

Question 12

food that cause acidosis

Answer 12

meats
grains
dairy

Question 13

SAD results in

Answer 13

net endogenous acid production

Question 14

pH ~

Answer 14

pH ~ renal function/pulm function

Question 15

respiratory disturbance

Answer 15

kidney changes total HCO3-

Question 16

renal disturbances

Answer 16

lungs change total PCO2

Question 17

acute disturbance

Answer 17

less time for compensation
= more acidodic

Question 18

chronic disturbance

Answer 18

more time for compensation
= less acidodic

Question 19

how much HCO3 do we reabsorb daily

Answer 19

4320 mEq/day

Question 20

how much H+ do we secrete daily

Answer 20

4390 mEq/day

Question 21

what does the excess H+ bind to?

Answer 21

other renal bases

Question 22

where is most of the bicarb reabsorbed?

Answer 22

PT (80%)

Question 23

where is the highest pH in nephron

Answer 23

PT/DT
pH ~ 6.7

Question 24

where is the lowest pH in nephron

Answer 24

IMCD (prior to urine excretion)
pH ~ 4.6 - 8

Question 25

what promotes H+ secretion/HCO3- reabsorption?

Answer 25

acidosis Ang2 aldosterone decr ECFV - incr RAAS hypokalemia - type A cells - ammoniagenesis

Question 26

principle cells

Answer 26

incr K+ secretion incr NHE - incr H+ secretion - incr HCO3- reabsoption

Question 27

Type A cell

Answer 27

incr K+ reabsorb incr H+ secretion incr HCO3- reabsorb

Question 28

ammoniagenesis will ____ HCO3-

Answer 28

incr HCO3-

Question 29

hypokalemia

Answer 29

increase H/K+ ATP pump - incr K+ reabs - incr H+ secretion ** incr HCO3- reabs

Question 30

ammoniagenesis

Answer 30

NH3 secreted OUT or NH3 + H+ -> NH4 - NH4 secreted out

Question 31

incr Ang2

Answer 31

metabolic alkalosis incr NHE - Na+ reabs - H+ secreted - HCO3- reabsorbed

Question 32

incr acid load is found in

Answer 32

PT/TAL

Question 33

incr acid load causes

Answer 33

incr HCO3- transporters == incr HCO3- reabs

Question 34

CD effects

Answer 34

incr H/K ATPase aldosterone hyperkalemia

Question 35

H/K ATPase

Answer 35

incr H+ secretion incr HCO3- reabs favors metabolic alkalosis

Question 36

aldosterone effects

Answer 36

incr K+ secretion incr K+ excretion incr BK/ROMK incr ENAC incr Na/K ATPase

Question 37

in acidosis states we upregulate what in the CD

Answer 37

H/K ATPase H ATPase

Question 38

when does H/K+ ATPase become more active

Answer 38

hypokalemia

Question 39

hypokalemia causes

Answer 39

incr H+ secretion incr HCO3- reabsorption

Question 40

does aldosterone favor hypo or hyperkalemia

Answer 40

hyperkalemia

Question 41

hyperkalemia means

Answer 41

there is way more K+ than the H/K+ ATPase can reabsorb, so more will be excreted out you will reabsorb more K+ than in normal conditions

Question 42

______ is permissive of acid base disturbances

Answer 42

aldosterone

Question 43

primary hyperaldosteronism

Answer 43

incr met alkalosis - incr H+ secretion - incr HCO3- reabs

Question 44

21/11 beta deficiency

Answer 44

incr met acidosis

Question 45

K+ channels in acidic state

Answer 45

decreased open probabilioty

Question 46

K+ channels closer to physiologic pH

Answer 46

incr open probability

Question 47

alkalosis: chronic

Answer 47

incr K+ channel open prob incr K+ secretion HYPOkalemia

Question 48

acidosis: acute

Answer 48

decr Na+/K+ decr K+ channel perm HYPERkalemia

Question 49

acidosis: chronic effect in sk muscl

Answer 49

incr HKE incr plasma K+ incr aldosterone

Question 50

acidosis: chronic effect in PT

Answer 50

incr ECFV - incr RAAS/aldo incr tubular flow - incr K+ secretion HYPOkalemia

Question 51

what factors cause incr H+ secretion/incr HCO3- reabs?

Answer 51

incr PCO2 incr H+ decr HCO3- decr ECFV - incr ANG2 - incr aldosterone - incr NHE - incr H/K ATP

Question 52

"new HCO3-"

Answer 52

some other base for H+ to bind to H+ + renal base 70mEq/day

Question 53

max free [H+] in urine

Answer 53

0.03 mmol/L

Question 54

renal bases

Answer 54

phosphate sulfate ammonia

Question 55

primary buffer

Answer 55

phosphate

Question 56

what is different about ammoniagenesis?

Answer 56

generates 2 extra HCO3-

Question 57

what is broken down in ammoniagenesis

Answer 57

glutamine

Question 58

kidney function

Answer 58

excrete metabolic acids regulate plasma [HCO3-] prevent bad buffering

Question 59

when do you have an incr risk of metabolic acidosis

Answer 59

with low GFR

Question 60

if you want to excrete acid:

Answer 60

free filter HCO3- at glom reabso 80% filtered HCO3- in PT reabsb 19% HCO3- in TAC/DT/CD secrete in DT/CD H+ H2PO4- NH4+ excrete acidic urine H2PO4- NH4+

Question 61

if you want to excreted base

Answer 61

free filter HCO3- reabs 80% HCO3- in PT reabs less HCO3- in TAF/DT/CD (10%) secrete HCO3- in DT/CD excrete alkaline urine with more HCO3- than normal