Which physiological change occurs when the chest expands during inhalation?

When the chest expands during inhalation, the diaphragm contracts and moves downward, while the intercostal muscles between the ribs contract, pulling the ribs upward and outward. This expansion of the chest cavity leads to an increase in the volume of the thoracic cavity. According to Boyle's law, which states that pressure is inversely proportional to volume, an increase in volume results in a decrease in pressure within the thoracic cavity.

As the pressure in the thoracic cavity decreases, it becomes lower than atmospheric pressure outside the body. This pressure gradient allows air to flow into the lungs from the environment, facilitating inhalation and enabling the body to take in oxygen. This physiological change is essential for normal breathing and gas exchange in the lungs.

The other options do not accurately describe the events that occur during inhalation, making them less relevant in the context of this question.