Transpulmonary pressure is defined as Palv minus Ppl and determines what?

Transpulmonary pressure is defined as Palv minus Ppl and determines what?

• A. Lung volume
• B. Airway resistance
• C. Cardiac output
• D. Gas exchange

Answer: (A)

Transpulmonary pressure is the distending pressure across the lung wall, calculated as alveolar pressure minus pleural pressure. It is the force that drives lung expansion. When this pressure difference increases, the lungs expand more and lung volume rises; when it decreases, the lungs recoil and volumes fall. Thus, transpulmonary pressure directly determines how much air-filled volume the lungs hold. Airway resistance, cardiac output, and gas exchange are influenced by other factors (airway size, cardiovascular dynamics, diffusion and perfusion), but the volume of the lungs at a given moment is governed by this distending pressure.

Transpulmonary pressure is the distending pressure across the lung wall, calculated as alveolar pressure minus pleural pressure. It is the force that drives lung expansion. When this pressure difference increases, the lungs expand more and lung volume rises; when it decreases, the lungs recoil and volumes fall. Thus, transpulmonary pressure directly determines how much air-filled volume the lungs hold. Airway resistance, cardiac output, and gas exchange are influenced by other factors (airway size, cardiovascular dynamics, diffusion and perfusion), but the volume of the lungs at a given moment is governed by this distending pressure.