What happens to the diaphragm during exhalation?

During exhalation, the diaphragm relaxes, which is a key part of the breathing process. When the diaphragm is at rest or begins to relax, it moves upward into the thoracic cavity, reducing the volume of the chest cavity. This decrease in volume creates a pressure difference that forces air out of the lungs.

The relaxation of the diaphragm allows the elastic tissues in the lungs to recoil, helping push air out. This process is considered passive because it does not require muscular effort once the diaphragm is relaxed. The combination of the diaphragm relaxing and the elasticity of the lung tissues works together to expel the air effectively.

In contrast, during inhalation, the diaphragm contracts to increase thoracic volume and draw air in, emphasizing the role of the diaphragm during these two opposing phases of respiration. Thus, understanding the function of the diaphragm during exhalation highlights how respiratory mechanics operate to facilitate breathing.