Relate the gas laws to pulmonary ventilation (pressure - volume relationships fo

I'm assuming you're referring to Boyle's law?

Boyle's Law: In a container filled with gas, if you decrease the volume, the pressure will correspondingly increase, and vice versa (or P*V=K)

During inspiration, the volume of the thoracic cavity increases and air is drawn into the lung. The increase in volume is brought about partly by contraction of the diaphragm and partly by the actions of the intercostals muscles. These muscular actions increase the size of the thoracic cavity and air flows in due to the reduced pressure inside the chest (inhalation; governed by Boyles law which states that the pressure of a gas is inversely proportional to its volume). Inspired air flows down to the terminal bronchioles by bulk flow. Beyond that point, the combined cross-sectional area of the airways is so enormous because of the large number of branches, that the forward velocity of the gas becomes very small. Diffusion of gas within the airways then takes over as the dominant mechanism of ventilation in the respiratory zone. The rate of diffusion within the airways is so rapid, and the distances covered arson short, that differences in concentration within the alveoli are virtually abolished within a second.