Question

Exchange of gases between the blood and the tissues of the body takes place by which of the following mechanisms?

• A. Breathing
• B. Diffusion
• C. Active transport
• D. Counter-current exchange

Answer 1

The correct option is B

Diffusion

Diffusion is the process by which exchange of gases take place between blood and body tissues. Respiratory gas is transported to each and every cell by blood. Tiny capillaries provide the blood flow to even remote parts of the body tissue. Then the gases - oxygen from the blood to tissue fluid and carbon dioxide from tissue fluid to blood - diffuse. The diffusion takes this particular direction due to differences in the concentration of these gases.