Transpulmonary Pressure PL is defined as pressure gradient between which two spaces?

Transpulmonary Pressure PL is defined as pressure gradient between which two spaces?

• A. Palv and Ppl
• B. Ppl and Patm
• C. Palv and Patm
• D. PIP and Pplat

Answer: (A)

Transpulmonary pressure is the pressure gradient across the lung wall, defined as the alveolar pressure (Palv) minus the intrapleural pressure (Ppl). This difference is the distending force that keeps the lung expanded and opposes the chest wall’s recoil, driving lung inflation. Alveolar pressure reflects the pressure inside the airspaces, while pleural pressure is the pressure in the pleural cavity; subtracting the latter from the former gives the true pressure acting to expand the lungs. Atmospheric pressure is outside the system and does not define this gradient, and the other options refer to airway pressures or to lung-to-atmosphere pressure differences that don’t represent the transpulmonary gradient.

Transpulmonary pressure is the pressure gradient across the lung wall, defined as the alveolar pressure (Palv) minus the intrapleural pressure (Ppl). This difference is the distending force that keeps the lung expanded and opposes the chest wall’s recoil, driving lung inflation. Alveolar pressure reflects the pressure inside the airspaces, while pleural pressure is the pressure in the pleural cavity; subtracting the latter from the former gives the true pressure acting to expand the lungs. Atmospheric pressure is outside the system and does not define this gradient, and the other options refer to airway pressures or to lung-to-atmosphere pressure differences that don’t represent the transpulmonary gradient.