Gaseous exchange Flashcards
What does gaseous exchange involve?
Getting oxygen from the lungs and into the blood, then to the working muscles.
Removing carbon dioxide from the muscles into the blood, and getting it to the lungs where it is expired.
What is gaseous exchange?
The exchange of gases
Define partial pressure
The pressure exerted by a single gas in a mixture of gases.
Define diffusion
The movement of gas from an area of high concentration to an area of low concentration.
Define diffusion gradient
How quickly diffusion takes place
What is partial pressure expressed as?
pO2 mm Hg / pCO2 mm Hg
What does a high diffusion gradient mean?
There will be a fast rate of diffusion
Give the 13 point process
- Breathe in
- Pp of O2 in alveoli is higher than in the blood
- O2 diffuses into blood (high -> low)
- Rate that diffusion occurs depends on diffusion gradient
- Diffusion continues until pressure in both is equal
- Blood becomes oxygenated (oxyhaemoglobin)
- Blood moves to the muscles
- Same process for movement of O2 into muscles
- Oxygen used for muscular contraction
- CO2 produced as waste product
- Pp of CO2 increases in muscles
- Above process is reversed - CO2 diffuses into blood (carbaminohaemoglobin)
- CO2 then transported to lungs to be expired.