Answer
At the beginning of inhalation the intrapeural pressure is about 756 mm Hg. As the diaphragm contracts in the process of inhalation, the intrapleural volume increases and the intra-pleural pressure drops to about 754 mm Hg.
Work Step by Step
As contraction ends and the diaphragm relaxes, intrapleural volume returns to norma, and intrapleural pressure returns to 756 mm Hg.
