What is the act of expelling air from the lungs known as?

The act of expelling air from the lungs is known as expiration. This process occurs when the diaphragm and intercostal muscles relax, leading to a decrease in thoracic volume and an increase in pressure within the lungs. As a result, air is pushed out of the lungs and flows through the airways and out of the body.

Understanding expiration is essential in the broader context of respiration, which involves both the intake of oxygen and the elimination of carbon dioxide. Ventilation refers to the overall process of moving air in and out of the lungs, but specifically identifies the movement during expiration as a crucial part of this cycle. Inspiration is the inhalation phase where air enters the lungs, while respiration encompasses the entire process of gas exchange. Recognizing these distinctions highlights the importance of expiration as a vital component of the respiratory system.