What is the process of expelling air from the lungs called?

The process of expelling air from the lungs is called exhalation or exhaling. During this process, the diaphragm and intercostal muscles relax, allowing the lungs to decrease in volume, which pushes air out of the lungs and through the airways. This is a key part of the respiratory cycle, allowing the body to remove carbon dioxide, a waste product of metabolism, and take in fresh oxygen during the subsequent inhalation.

Inhalation refers specifically to the process of taking air into the lungs, while ventilation is a broader term that can refer to the process of moving air in and out of the lungs in general. Respiration encompasses all physiological processes involved in gas exchange, including cellular respiration, which utilizes the oxygen transported from the lungs.