What is the primary function of the diaphragm during respiration?

The primary function of the diaphragm during respiration is to create negative pressure in the lungs. When the diaphragm contracts and moves downward, it increases the volume of the thoracic cavity. This expansion lowers the pressure within the lungs relative to the outside atmosphere, allowing air to flow in through the airways. This process is crucial for inhalation, as it enables the lungs to fill with air.

While the diaphragm does play a role in various other functions, such as contributing to abdominal compression or influencing vocalization, its essential action in the context of respiration is the creation of that negative pressure. This function highlights the diaphragm's role as a key muscle in breathing mechanics, emphasizing its importance in ensuring efficient air exchange in the respiratory system.