constant partial pressure

Constant partial pressure refers to the steady, unchanging level of a specific gas within a mixture, such as in the lungs or bloodstream. It means that the force exerted by that gas on the walls of its container remains consistent, allowing gases to move naturally to balance concentrations between areas (like in breathing or blood flow). This concept helps explain how oxygen is absorbed by blood and carbon dioxide is released, driven by differences in their partial pressures across membranes, ensuring efficient gas exchange even as conditions change.