Pressure inside the lungs

Pressure is critical for living organisms to be able to breathe. There are different pressures that will help the lungs stay inflated and carry out the process of respiration:

• The atmospheric pressure is the pressure within the atmosphere of Earth which is 760 mmHg millimeters of mercury at sea level.

• The intrapulmonary pressure, also known as alveolar pressure (Palv), is the pressure inside alveoli.

• The intrapleural pressure is the air pressure within the pleural cavity. Negative values always represent it.

• The transpulmonary pressure (PL), also known as transmural pressure, is the distending pressure of the lung. It measures the elastic forces responsible for the passive tissue recoil of the lungs, which are necessary for the process of expiration. It is defined by the difference between intrapulmonary and intrapleural pressure.