What function does the diaphragm perform during breathing?

The diaphragm plays a crucial role in the process of breathing by contracting and flattening when inhaling, which leads to an increase in the volume of the thoracic cavity. This change in volume creates a negative pressure that draws air into the lungs, allowing for oxygen exchange. As the diaphragm moves downward, it provides more space for the lungs to expand. This function is essential for effective respiration, making the diaphragm a key muscle in the respiratory system.

The other options describe functions that are not related to the diaphragm. For example, enzymes for digestion are produced by other organs, grouping of organs does not pertain specifically to the diaphragm's function in breathing, and the regulation of chemical levels in the blood is managed by different systems in the body, such as the respiratory and renal systems.