Final answer:
During inhalation, an increase in lung volume leads to a decrease in pressure. During exhalation, a decrease in lung volume leads to an increase in pressure.
Step-by-step explanation:
According to Boyle's Law, the pressure and volume of a gas are inversely related. When the lung volume increases during inhalation, the pressure inside the lungs decreases. Conversely, when the lung volume decreases during exhalation, the pressure inside the lungs increases.