What is the process of moving gases (O2 and CO2) between inhaled air and the pulmonary circulation of blood called?

The correct answer pertains to the specific interaction of gases occurring in the lungs known as respiration. This process encompasses the exchange of oxygen and carbon dioxide between the alveoli in the lungs and the bloodstream.

Respiration involves two primary actions: external respiration and internal respiration. External respiration refers to the exchange of gases within the lungs, where oxygen is absorbed into the blood, and carbon dioxide is released from the blood into the alveoli to be exhaled.

While ventilation refers to the physical act of breathing—specifically, the movement of air into and out of the lungs—it does not cover the actual exchange of gases that occurs at the level of the alveoli. In contrast, diffusion is the underlying mechanism that drives the movement of those gases across the alveolar membrane, but it is part of the broader process of respiration.

Oxygenation can describe the process of adding oxygen to the blood, but it is not as comprehensive as respiration, which includes the removal of carbon dioxide as well. Understanding these distinctions helps clarify why respiration is the most appropriate term for the entire process of gas exchange in the lungs.