Final answer:
Boyle's law, which describes the pressure-volume relationship of gases, explains the changes of lung pressure during inhalation, with lower pressure due to increased lung volume, and exhalation, with higher pressure due to decreased lung volume.
Step-by-step explanation:
The pressure and volume relationship of gases, which is explained by Boyle's law, is directly applicable to understanding how pressures change within the lungs during inhalation and exhalation. During inhalation, lung volume increases as the muscles expand the chest and the diaphragm moves downward, causing the pressure inside the lungs to drop below atmospheric pressure. The pressure between the lungs and chest wall is even lower to overcome the surface tension in the lungs. Conversely, during exhalation, the lung volume decreases as the muscles relax and the surface tension in the alveoli creates a positive pressure inside the lungs, pushing air out.
In forced exhalation, such as when blowing up a balloon, the diaphragm and chest muscles create an even higher pressure difference. When the lungs become less pliable or if there is increased resistance in the lungs, such as in certain diseases, the ratio of pressure-to-volume changes, showcasing a deviation from normal Boyle’s law behavior within the physiological context.