During exhalation, what happens to the diaphragm?

During exhalation, the diaphragm plays a crucial role in the respiratory process. When we exhale, the diaphragm relaxes, which is essential for facilitating the movement of air out of the lungs. As the diaphragm relaxes, it moves upward into the thoracic cavity, which reduces the volume of the thoracic space. This decrease in volume leads to an increase in pressure within the lungs compared to the atmospheric pressure outside. As a result, air is pushed out of the lungs, effectively completing the exhalation process.

The mechanics of breathing involve changes in pressure and volume, based on Boyle's law, which states that the pressure of a gas is inversely related to its volume. Therefore, as the space inside the thoracic cavity decreases due to the diaphragm's upward movement, the pressure increases, causing air to flow out. Understanding this physiological mechanism is crucial for grasping how normal respiration operates, and it illustrates the active role of the diaphragm during exhalation.