What is the process called when air is expelled from the lungs?

• A. Inhale
• B. Exhalation
• C. Ventilation
• D. Respiration

Answer: (B)

The process of expelling air from the lungs is specifically termed exhalation. During exhalation, the diaphragm and intercostal muscles relax, causing the chest cavity to decrease in volume, which results in an increase in pressure within the lungs. This pressure difference drives air out of the lungs and into the atmosphere. Exhalation is a crucial part of the respiratory cycle, allowing for the removal of carbon dioxide from the body, an essential function for maintaining proper blood gas levels and overall homeostasis.

Inhalation, in contrast, refers to the intake of air into the lungs. Ventilation encompasses both inhalation and exhalation as it describes the movement of air in and out of the lungs. Respiration is a broader term that includes the exchange of gases in the lungs (external respiration) and at the cellular level (internal respiration), rather than just the act of air expulsion. Thus, exhalation is the precise term that identifies the act of air being expelled from the lungs.