Acid Base Balance

Question 1

what is the normal pH of blood

Answer 1

7.35-7.45

Question 2

what happens to the potassium levels in alkaline conditions

Answer 2

you get hypokalaemia

Question 3

what happens to potassium levels in acidic conditions

Answer 3

you get hyperkalaemia

Question 4

describe how bicarbonate is recovered in the nephron

Answer 4

• Na/K/ATPase produces a low intracellular Na concentration
• this allows the NHE to move Na in and H out
• the H+ reaction with the HCO3 in the lumen to give H20 and C02
• the CO2 diffuses into the tubule cells where it dissociates back into HCO3

Question 5

where in the nephron does bicarbonate recovery occur?

Answer 5

PCT

Question 6

where is bicarbonate produced in the nephron

Answer 6

PCT and DCT

Question 7

describe bicarbonate production in the PCT

Answer 7

glutamine is broken down into alpha ketoglutarate and then into bicarbonate
this produces ammonium

Question 8

describe how bicarbonate is produced in the DCT

Answer 8

through the reaction of CO2 and H20

Question 9

true or false: the DCT passively secretes H+ into the lumen

Answer 9

false - its active

Question 10

how is the H+ secreted by the DCT buffered

Answer 10

with the ammonium produced in the PCT or phosphate

Question 11

what are some causes of metabolic acidosis

Answer 11

diabetes
exercise
hyperkalaemia

Question 12

how does diabetes cause metabolic acidosis

Answer 12

as ketone bodies are produced due to respiring using fatty acids. these ketone bodies then react with the HCO3, reducing the HCO3 levels

Question 13

if there is no anion gap change what is the cause of the metabolic acidosis

Answer 13

renal problems or persistent diarrhoea

Question 14

if there is no change to the anion gap then which ion is replacing the HCO3

Answer 14

chloride

Question 15

name some causes of metabolic alkalosis

Answer 15

prolonged vomiting

hypokalameia

Question 16

name some causes of respiratory acidosis

Answer 16

hypoventilation

type 2 respiratory failure

Question 17

give some examples of conditions that cause type 2 respiratory failure

Answer 17

COPD, severe asthma, drug overdose, neuromuscular disease

Question 18

give some causes of respiratory alkalosis

Answer 18

type 1 respiratory failure

hyperventilation

Question 19

describe the problem:
pH = high 
pCO2 = low 
HCO3 = low 
pO2 = normal

Answer 19

respiratory alkalosis

partial compensation

Question 20

describe the problem:
pH = low
pCO2 = normal
HCO3 = low
pO2 = normal

Answer 20

metabolic acidosis

not compensated

Question 21

describe the problem:
pH = low
pCO2 = high
HCO3 = high
pO2 = low

Answer 21

respiratory acidosis
partial compensation
hypoxic

Question 22

describe the problem:
pH = high 
pCO2 = normal
HCO3 = high
pO2 = normal

Answer 22

metabolic alkalosis

not compensated

Question 23

describe the problem:
pH = normal
pCO2 = high
HCO3 = high
pO2 = low

Answer 23

respiratory acidosis

fully compensated

Question 24

describe the problem:
pH = normal
pCO2 = low
HCO3 = low
pO2 = normal

Answer 24

metabolic acidosis

fully compensated

Question 25

describe the problem:
pH = high
pCO2 = low
HCO3 = normal
pO2 = normal

Answer 25

respiratory alkalosis

not compensated