What role does the diaphragm play during exhalation?

The role of the diaphragm during exhalation is crucial for the mechanics of breathing. When exhalation occurs, the diaphragm actually relaxes rather than contracts. As the diaphragm relaxes, it moves upwards, decreasing the volume of the thoracic cavity. This decrease in volume increases the pressure inside the thoracic cavity compared to atmospheric pressure, which forces air out of the lungs and into the environment.

While some choices might mention the contraction of the diaphragm or its relationships to air intake or cavity separation, it is important to focus on its relaxation during exhalation as the primary mechanism that facilitates the expulsion of air. The diaphragm’s ability to change from a dome shape to a flat position and vice versa is what allows for effective inhalation and exhalation. Understanding this process is fundamental in studying the anatomy and function of the respiratory system.