16. Acid Base Balance

Question 1

Henderson Hasselbach equation?

Answer 1

pH= pK + log [HCO3]/0.03PCO2

Question 2

principal way kidneys maintain acid-base balance?

Answer 2

HCO3 reabsorption

Question 3

hw does kidney reabsorb HCO3 in PT?

Answer 3

secretes H and uses carbonic anhydrase

Question 4

hw does the kidney form new HCO3?

Answer 4

combine H2O and CO2 to form H2CO3

Question 5

biproducts of glutamine metabolism?

Answer 5

NH4 and OH

Question 6

principal H secretory system in a-intercalated cells?

2 secondary?

Answer 6

H-ATPase

Cl/HCO exchanger
H-K antiport

Question 7

principal H secretory system in PT?

secondary?

Answer 7

Na-H antiport (NHE)

Na/HCO co-transport

Question 8

wc part of acid base regulaiton in the kidney does not excrete excess H?

Answer 8

PT reabsorption

Question 9

net acid excretion equation?

Answer 9

NAE= (UNH4)(V) + (TA)(V) – (UHCO3)(V)

Question 10

physiological significance of NAE?

Answer 10

NAE is equal to net amount of new HCO generated

Question 11

2 things inhibiting NHE3?

Answer 11

lithium, PTH, PKA and amiloride

Question 12

2 things stimulating NHE3?

Answer 12

AngII and endothelin

Question 13

hypokalemia affect on H excretion in PT?

how does this affect HCO3?

Answer 13

Hypokalemia -> K excreted from cell -> H taken into celll –> inc NHE and H/KATPase

results in increased HCO3 reabsorption

Question 14

most common cause of hypokalemia?

Answer 14

hyperaldosteronism

Question 15

wt happens to kidneys in acidosis?

Answer 15

stimulates glutamine metabolism –> increased HCO generation

Question 16

wt is the result of buffering in metabolic acidosis?

Answer 16

dec serum HCO3

inc serum K

Question 17

values for pH, HCO3 and PCO2 in metabolic acidosis?

Answer 17

all dec

Question 18

anion gap formula?

Answer 18

Na - Cl - HCO3

Question 19

wt can increase anion gap?

Answer 19

hyperalbuminemia

Question 20

cause of type 1 RTA?
pathology?
plasma K?

Answer 20

defect in H-ATPase in CT
less H excretion
dec. K

Question 21

cause of type 2 RTA?
pathology?
plasma K?

Answer 21

reduced NHE activity (dec CA) in PT
dec HCO3 reabsorption
dec K

Question 22

cause of type 4 RTA?
pathology?
plasma K?

Answer 22

hypoaldosteronism

dec H excretion in CT

Question 23

tx for metabolic alkalosis?

Answer 23

NaCl infusion

Question 24

wt happens in intracellular buffering in repiratory alkalosis?

Answer 24

H reacts with HCO3 which decreases 2mEq/L per 10 mm Hg decrease in PCO2

Question 25

wt happens in renal compensation in respiratory alkalosis?

Answer 25

HCO3 decreases 5mEq/L per 10 mm Hg decrease in PCO2

Question 26

wt happens in intracellular buffering in respiratory acidosis?

Answer 26

HCO3 increases 1 mEq/L per 10 mm Hg increase in PCO2

Question 27

wt happens in renal compensation in respiratory acidosis?

Answer 27

HCO3 increases 4 mmmol/l for every 10 mmHg in PCO2 above 40mmHg

Question 28

compensation for resp acidosis?

Answer 28

acidic urine | HCO3 conversion and synthesis

Question 29

compensation for resp alkalosis?

Answer 29

alkaline urine

Question 30

compensatino for metabolic acidosis?

Answer 30

hyperventilation | alkaline urine

Question 31

compensation for metabolic alkalosis?

Answer 31

hypoventilation | alkaline urine

Question 32

hw does hypokalemia cause affect alpha intercollated cells?

Answer 32

K depletion --> inc H/K ATPase to bring K back in

Question 33

does hypokalemia cause acidosis or alkalosis?

Answer 33

alkalosis

Question 34

expected pCO2 for compensaiton in metabolic acidosis?

Answer 34

pCO2 = 1.5 x [HCO3] + 8 (+/-2)

Question 35

effect of Cl depletion?

Answer 35

inc HCO3 reabsorption --> metabolic alkalosis

Question 36

expected pCO2 for compensation in metabolic alkalosis?

Answer 36

pCO2 = 0.7 * [HCO3] + 20 (+/-5)