Which of the following processes occurs during inhalation?

During inhalation, the primary action involves the contraction of the intercostal muscles and the diaphragm. When these muscles contract, the diaphragm moves downwards and the ribcage expands, causing a larger thoracic cavity. This increase in volume results in a decrease in pressure within the thoracic cavity compared to the atmospheric pressure, causing air to flow into the lungs.

Inhalation is vital for bringing fresh oxygen into the lungs, where it can be exchanged for carbon dioxide in the bloodstream. Understanding this process is crucial for grasping the mechanics of respiration and how the body obtains the oxygen it needs. The contraction of the diaphragm and intercostal muscles creates the necessary negative pressure for air to enter the lungs effectively.