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)