Acid Base Balance

Question 1

how do the lungs and kidneys maintain acid-base balance?
1. ICF & ECF buffers (HC03, H2CO3) (1st line defence)

2.Lungs: Alveolar ventilation which controls PaC02 (thus improving efficiency of HC03, H2CO3 buffers)

3.Kidneys: Excretion H+ which controls ??? (slow)

Answer 1

3. HC03

Question 2

TRUE or FALSE: The concentration of H2CO3 is determined by lungs and their respiratory capacity

Answer 2

TRUE

Question 3

The concentrate of non volatile acids is determined by the ??? & the amount of buffers produced eg HCO3 and H+ excreted

Answer 3

kidneys

Question 4

Kidneys regulate HCO3- by reabsorbing & making more bicarb & excreting ???

Answer 4

H+

Question 5

Respiratory system regulates H2CO3 by changing the rate and ??? of respiration ie rapid or slow, deep or shallow respiration

Answer 5

depth

Question 6

too much acid = lungs detect a rise in H2CO3 and H+ and increase Respiratory Rate to ‘blow off’ CO2

kidneys excrete acidic urine & reabsorb ???

Answer 6

bicarbonate

Question 7

TRUE or FALSE: decompensation = If kidneys & lungs cannot compensate adequately, the
ratio changes, serum pH moves out of normal range –> Altered cell metabolism and function

Answer 7

TRUE

Question 8

metabolic or respiratory acidosis is characterised by:
- pH <7.35 &
- Primary disturbance: Low HC03
- pC02 normal

Answer 8

metabolic

Question 9

First line of defence against acidosis: combine acids with buffers in ???

Answer 9

plasma

Question 9

sign of metabolic acidosis is ??? and Increased respiratory rate (RR) due to lungs attempting to ‘blow off’ extra C02 → reduces carbonic acid level

Answer 9

acidic urea

Question 9

manifestations of metabolic acidosis or alkylosis is the following:
- low blood pH i.e. < 7.35 eg by increase in ketone bodies
- HCO3– is reduced because H+ is increased
- Compensatory ↑ resp rate & depth (blow off more C02), acidic urine

• Other: anorexia, weakness, confusion

Answer 9

acidosis

Question 10

what type of acidosis is characterised by:
- pH <7.35 &
- Normal HC03
- pC02 high

Answer 10

respiratory acidosis

Question 11

TRUE or FALSE bicarb can buffer
carbonic acid

Answer 11

FALSE

Question 12

what type of acidosis is caused by
hypoventilation. Results in hypoxia and accumulation of C02 due to decreased RR?

Answer 12

respiratory acidosis

Question 13

in ??? acidosis you do not have the capacity to get rid of excess acid via the lungs so you will see a rise in the amount of H2CO3 as a result of the
rise in the pCO2 because you are ‘under respiring’

Answer 13

respiratory acidosis

Question 14

Compensation for which alkalosis involves ↓ respiratory rate to retain C02 / carbonic acid levels?

Answer 14

metabolic

Question 15

Decreased respiratory rate (RR). Attempting to retain extra C02 →increase carbonic acid level in which type of alkalosis?

Answer 15

metabolic

Question 15

causes of ??? alkalosis include:
- excess of antacids
- excess solutions eg sodium
bicarbonate
- excess vomiting

Answer 15

metabolic

Question 15

which alkalosis is characterised by:
- pH >7.45 &
- normal HC03
- Low pC02

Answer 15

respiratory

Question 16

TRUE or FALSE: respiratory alkalosis is caused by decrease in
C02 from
- Hyperventilation
- Mechanical ventilation
- Some drugs

Answer 16

TRUE

Question 16

in the case of ??? alkalosis, decreased C02 results in constriction of cerebral blood vessels – light headed, dizzy, numbness, seizures

Answer 16

respiratory alkalosis

Question 17

What happens if respiratory rate increases ?

Answer 17

Increasing the respiration rate “blows off” CO2 = decreasing carbonic acid levels = reduction in the total amount of acid in the body –> increase in pH

Question 18

If HCO3- is low how will H2CO3
levels change? i.e. metabolic acidosis

Answer 18

Carbonic acid levels decrease in
proportion to the bicarbonate loss

Question 19

How does renal failure impact on acid base balance?
Hint: bile acid, bicarb

Answer 19

Serum pH decreases as kidneys cannot excrete much acid nor produce as much bicarbonate for
buffering

Question 20

Why & what does decrease of Respiratory Rate after vomiting do?
Hint: Vomiting= loss of acid.

Answer 20

Vomiting= loss of acid. To rebalance the body the lungs allow CO2 to accumulate