Lecture 5-Gas Exchange Flashcards
1
Q
What are the five layers making up the diffusion barrier at the air-blood interface?
A
- alveolar epithelial cell
- interstitial fluid
- capillary endothelial cell
- plasma
- red cell membrane
2
Q
What factors affect the rate of diffusion across the air-blood interface?
A
- surface area
- resistance to diffusion
- gradient of partial pressure
3
Q
How many times faster does CO2 diffuse than O2?
A
20
4
Q
How does fibrotic lung disease affect gas exchange?
A
Thicker alveolar membrane slows gas exchange therefore pO2 lower and pCO2 normal
5
Q
How does pulmonary oedema affect gas exchange?
A
Fluid in interstitial space increases diffusion distance therefore pCO2 normal and pO2 low
6
Q
How does emphysema affect gas exchange?
A
Destruction of alveoli reduces surface area for gas exchange
