What is the main mechanism for the exchange of O₂ and CO₂ in the body?
What is the main mechanism for the exchange of O₂ and CO₂ in the body?
Transport by blood vessels
Active transport by specialized cells
Diffusion
Facilitated diffusion
Solution
Exchange of O₂ and CO₂ at the alveoli and tissues occur by diffusion. Rate of diffusion is dependent on the partial pressure gradients of O₂ (pO₂) and CO₂ (pCO₂), their solubility as well as the thickness of the diffusion surface.