What occurs to the lung volume during inhalation?

During inhalation, the process of breathing in, lung volume increases to accommodate incoming air. This increase occurs as the diaphragm contracts and moves downward while the intercostal muscles (located between the ribs) contract to lift the rib cage up and out. This expansion creates a negative pressure within the thoracic cavity compared to the external atmospheric pressure, allowing air to flow into the lungs.

As the volume inside the thoracic cavity increases, this allows the lungs to expand, filling with fresh air. This essential mechanism is part of the respiratory process that facilitates gas exchange in the alveoli, where oxygen enters the bloodstream and carbon dioxide is expelled. Therefore, the correct understanding of inhalation is that lung volume must increase to allow for effective breathing and gas exchange.