C - Acid Base Handling (E)

Question 1

normal pH

Answer 1

7.35 to 7.46

Question 2

what is a buffer

Answer 2

weak acid and its base

Question 3

list 3 main biological buffers

Answer 3

bicarbonate
haemoglobin
phosphate
(also protein and bone)

Question 4

how can acid base balance be maintained in short and long term

Answer 4

short = bicarb
long = excretion of H+ in kidneys

Question 5

how can bicarb be regenerated

Answer 5

by carbonic acid (water and CO2)

Question 6

how are H+ excreted out of kidney cells

Answer 6

transport system with sodium

Question 7

how is co2 produced in body

Answer 7

aerobic metabolism of proteins / carbs / fats

Question 8

how is co2 balanced in body

Answer 8

increased resp rate to blow it off

Question 9

what is the main buffer in red blood cells

Answer 9

haemoglobin

Question 10

how is Hb a buffer for CO2

Answer 10

co2 binds to water producing bicarb and H+, the H+ then binds to Hb to make HHb

Question 11

causes of metabolic acidosis

Answer 11

increased H+ production - DKA
decreased H+ excretion - renal tubular acidosis / renal failure
bicarb loss - intestinal fistula

Question 12

primary abnormalities in metabolic acidosis

Answer 12

increased H+
decreased pH

Question 13

how can metabolic acidosis be compensated

Answer 13

fall in CO2 due to increased RR - reduces rise in H+

Question 14

give H+ conc and arterial PCO2 of
metabolic acidosis

Answer 14

low pH, low CO2

Question 15

give H+ conc and arterial PCO2 of resp alkalosis

Answer 15

high pH, low CO2

Question 16

give H+ conc and arterial PCO2 of resp acidosis

Answer 16

low pH, high CO2

Question 17

give H+ conc and arterial PCO2 of metabolic alkalosis

Answer 17

high pH, high CO2

Question 18

how are pH and H+ linked

Answer 18

inversed log - as H+ increases, pH decreases

Question 19

what is the primary abnormality in resp acidosis

Answer 19

increased CO2
–> increased H+ and slight increase in bicarb

Question 20

causes of resp acidosis

Answer 20

decreased ventilation
poor lung perfusion
impaired gas exchange

Question 21

how does the body compensate for resp acidosis

Answer 21

increased renal excretion of H+, plus increased generation of bicarb

Question 22

how does the lung vs kidney compensation speed compare

Answer 22

lungs are much quicker

Question 23

what are the H+ / CO2 / bicarb levels like in chronic resp acidosis

Answer 23

H+ near normal, but CO2 and bicarb elevated

Question 24

primary abnormality in metabolic alkalosis

Answer 24

decreased H+ / increased pH
increased bicarb

Question 25

causes of metabolic alkalosis

Answer 25

H+ loss eg pyloric stenosis
hypokalaemia
ingestion of xs bicarb

Question 26

how is metabolic alkalosis compensated for

Answer 26

increased CO2
- inhibiting respiratory centre (limited as you would die from not breathing)

Question 27

what is the primary abnormality in resp alkalosis

Answer 27

low Co2
then low H+ and bicarb

Question 28

causes of resp alkalosis

Answer 28

hyperventilation
- voluntary eg anxiety
- artificial ventilation
- stimulation of resp centre by drugs

Question 29

how does chronic resp alkalosis affect kidneys

Answer 29

reduced renal excretion of H+
reduced bicarb generation
still low co2 and bicarb even if pH normalises