Alveoli is the site for the gas exchange in the respiratory system of humans. Gas exchange occurs due to the gradient in the partial pressure of gases. During the process, the partial pressures of oxygen in alveoli is found to be

Question

Alveoli is the site for the gas exchange in the respiratory system of humans. Gas exchange occurs due to the gradient in the partial pressure of gases. During the process, the partial pressures of oxygen in alveoli is found to be (A) Less than that in deoxygenated blood. (B) More than that in oxygenated blood. (C) Equal to that in atmospheric air. (D) Less than that in tissues.

Tardigrade Admin · Accepted Answer

The pressure exerted by a particular gas in a mixture of gases is called partial pressure. For a smooth exchange of

O_{2}

, the partial pressure of

O_{2}

must be higher in alveoli than in the blood of capillary creating a gradient for movement of gases from high to low. It must be higher than deoxygenated blood and more than in tissues. The partial pressures of oxygen and carbon dioxide at different parts of the respiratory system is as follows:
Solution

Q. Alveoli is the site for the gas exchange in the respiratory system of humans. Gas exchange occurs due to the gradient in the partial pressure of gases. During the process, the partial pressures of oxygen in alveoli is found to be

Less than that in deoxygenated blood.

More than that in oxygenated blood.

Equal to that in atmospheric air.

Less than that in tissues.