Pleural cavity

The pleural cavity (cavum Pleurae) is the space between the parietal and visceral layers of the pleural membranes. The pleural cavity is filled with air. In addition to being filled with air, it also contains bubbles of serous fluid, which are called pleural effusions. The volume of these pleural effusions in healthy people is small and depends on body position and tidal volume (that is, it may increase in the supine position or during deep inspiration).

The pleural cavity performs important functions, primarily the function of protecting the chest organs, as well as the function of humidifying and heating the air. It isolates the lung from the external environment and allows the lungs to move freely down and up and occupy the entire chest cavity. In addition, it provides damping - reducing the sharpness of lung movements during breathing and vibration of the respiratory system as a whole. This allows you to reduce the unwanted effects of external and internal irritants on the chest wall, reduce pain and prevent damage to small vessels, joints and lung tissue.