What happens to the pressure in the thoracic cavity during diaphragm contraction?

During diaphragm contraction, the diaphragm, which is a dome-shaped muscle located at the base of the thoracic cavity, flattens and moves downward. This movement increases the volume of the thoracic cavity. According to Boyle's law, which states that pressure and volume are inversely related in a closed system, an increase in the volume of the thoracic cavity results in a decrease in pressure within that cavity.

As the diaphragm contracts, the negative pressure created inside the thoracic cavity facilitates air flow into the lungs, promoting inhalation. Therefore, during diaphragm contraction, the pressure in the thoracic cavity indeed decreases, allowing for effective breathing and gas exchange in the lungs.