Which process involves breathing and the exchange of gases in the lungs?

The process that involves breathing and the exchange of gases in the lungs is known as external respiration. This term specifically refers to the physiological mechanism where oxygen is taken into the body during inhalation, and carbon dioxide is expelled during exhalation. In the lungs, oxygen from the inhaled air passes through alveolar membranes into the bloodstream, while carbon dioxide from the blood moves in the opposite direction to be exhaled, facilitating gas exchange.

This process is distinct from internal respiration, which involves the exchange of gases between the blood and the tissues throughout the body. Cellular respiration refers to the metabolic processes that occur within cells, where the energy from nutrients is converted into ATP, utilizing oxygen and producing carbon dioxide as a byproduct. Gas diffusion simply describes the passive movement of gas from areas of higher concentration to areas of lower concentration but doesn’t encapsulate the full process of breathing and gas exchange in the lungs.

Therefore, external respiration specifically covers both the act of breathing and the accompanying gas exchange within the lungs, making it the correct choice.