If intrapulmonary pressure is 760 mm Hg, what would you expect the intrapleural pressure to be?

Intrapleural pressure is the pressure within the pleural cavity, which is the space between the lungs and the chest wall. Normally, intrapleural pressure is slightly negative compared to atmospheric pressure and intrapulmonary pressure, which is the pressure within the alveoli of the lungs.

If the intrapulmonary pressure (the pressure within the lungs) is 760 mm Hg, which is equivalent to atmospheric pressure at sea level, one would expect the intrapleural pressure to be slightly lower. Typically, intrapleural pressure is about 4 mm Hg less than intrapulmonary pressure during resting state (also known as functional residual capacity).

Therefore, if the intrapulmonary pressure is 760 mm Hg, the intrapleural pressure would usually be around 756 mm Hg. This negative pressure is crucial as it keeps the lungs inflated and prevents them from collapsing.