Physical Principles Governing Gas Exchange

Inhaled air contains a mixture of different gases like nitrogen, oxygen, and carbon dioxide, among others.

Dalton's law is fundamental to understanding gas behavior in this mix. According to this law, in a mixture of gases, each gas exerts its own pressure independently, known as partial pressure.

Partial pressure is calculated by multiplying the percent concentration of the gas in the mixture by the total pressure exerted by the mixture.

Gas diffusion relies on a partial pressure gradient, moving from high-pressure regions to low-pressure regions such as between the air, lungs, blood vessels, and cells.

In contrast, Henry's Law is useful in understanding the solubility of gases in body fluids.

It states that the quantity of a gas that dissolves in a liquid is proportional to its partial pressure and solubility.

For instance, blood can retain more CO₂ due to its higher solubility than O₂.

In contrast, inhaling nitrogen has minimal bodily impact because of its low solubility in the blood.