What best describes the diaphragm's role during inhalation?

The diaphragm plays a crucial role in the process of inhalation by contracting and moving downward. When the diaphragm contracts, it flattens, creating more space in the thoracic cavity. This increased volume leads to a decrease in pressure within the lungs compared to the outside atmospheric pressure, allowing air to flow in through the airways. This mechanism is fundamental to the respiratory process, as it enables effective gas exchange in the lungs.

By moving downwards during contraction, the diaphragm not only aids in drawing in air but also facilitates the expansion of the lungs. This explanation highlights the importance of the diaphragm in the act of breathing, illustrating its direct involvement in the mechanics of inhalation.