Control of Breathing and Respiratory Faliure Flashcards Preview

ESA 3 - Respiratory System > Control of Breathing and Respiratory Faliure > Flashcards

Flashcards in Control of Breathing and Respiratory Faliure Deck (76)
Loading flashcards...
1

What is meant by hypoxia? 

A fall in alveolar, thus arterial pO2

2

What is meant by hypercapnia? 

A rise in alveolar, thus arterial CO2

3

What is meant by hypocapnia? 

A fall in alveolar, thus arterial CO2

4

What is meant by hyperventilation? 

Ventilation increases with no change in metabolism 

Breathing more than you actually have to 

5

What is meant by hypoventilation? 

Ventilation decreases with no change in metabolism 

Breathing less than you have too 

6

What affect does pCO2 have on the plasma? 

It affects the pH 

7

What affect does hyperventilation have on the plasma? 

It decreases pCO2 and therefore increases pH 

8

What affect does hypoventilation have on the plasma? 

It increases pCO2 therefore decreases pH 

9

What are the effects of hypoventilation? 

  • Hypercapnia
  • Respiratory acidosis 
  • pH falls below 7.0

 

10

What is the result of the pH change in hypoventilation? 

Enzymes become lethally denatured 

11

What are the effects of hyperventilation? 

  • Hypocapnia 
  • Respiratory alkalosis 
  • pH rises above 7.6
  • Free calcium concentration falls 

 

12

What is the result of the free calcium fall in hyperventilation? 

Can fall enough to produce fetal tetany

13

Why does hyperventilation cause a fall in free calcium? 

Ca2+ is only soluble in acid, so when pH rises, Ca2+ cannot stay in the blood 

14

Why does a fall in free calcium cause tetany? 

Nerves become hyper-excitable 

15

What happens in respiratory acidosis? 

COin produced more rapidly than it is removed by the lungs. Alveolar pCO2 rises, so the concentration of dissolved CO2 rises to more than the concentration of HCO3-, producing a fall in plasma pH 

16

What happens in compensated respiratory acidosis? 

Respiratory acidosis persists, and the kidneys respond to low pH by reducing the excretion of HCO3-, thus restoring the ratio of concentration of dissolved CO2 to concentration of HCO3-, and therefore the pH 

17

What happens in respiratory alkalosis? 

CO2 is removed from alveoli more rapidly than produced. Alveolar pCOfalls, disturbing the ratio of concentration of dissolved CO2 to concentration HCO3-, producing a rise in plasma pH

18

What happens in compensated respiratory alkalosis? 

Respiratory alkalosis persists, and the kidneys respond to the high pH by excreting HCO3-, thus restoring the ratio of concentration of dissolved CO2 to concentration of HCO3-, and therefore the pH 

19

What happens in metabolic acidosis? 

Metabolic production of acid displaces HCO3- as the plasma is buffered, therefore the pH of the blood falls 

20

What happens in compensated metabolic acidosis? 

The ratio of [dissolved CO2] to [HCO3-] may be restored to near normal by lowering pCO2. The lungs increase ventilation to correct pH 

21

What happens in metabolic alkalosis? 

Plasma [HCO3-] rises, causing the pH of blood to rise 

22

Give an example of when metabolic alkalosis may occur

After vomiting 

23

What happens in compensated metabolic alkalosis? 

The ratio of [dissolved CO2] to [HCO3-] may be restored to near normal by raising pCO2. The lungs decrease ventilation to correct pH 

24

What detects a falling arterial pO2?

Peripheral chemoreceptors located in the carotid and aortic bodies 

25

What are the carotid and aortic bodies stimulated by? 

A decrease in oxygen supply relative to their own oxygen usage

26

What is the oxygen usage of the carotid and aortic bodies? 

Small 

27

What size drops in oxygen do the carotid and aortic bodies respond to? 

Only large ones 

28

What is the result of stimulation of the receptors located in the carotid and aortic bodies? 

  • Increases the tidal volume and rate of respiration 
  • Changes in circulation directing more blood to the brain and kidneys 
  • Increased pumping of blood by the heart 

 

29

Other than changes in pO2, what to the peripheral chemoreceptors in the carotid and aortic bodies detect? 

Changes in pCO2

30

What is the limitation of the detection of changes in pCOby the carotid and aortic bodies? 

They are insensitive