What is the primary purpose of the pleura surrounding the lungs?

The primary purpose of the pleura surrounding the lungs is to provide lubrication during respiration. The pleura consist of two layers — the visceral pleura that adheres to the lungs and the parietal pleura that lines the chest wall. Between these two layers is a pleural cavity filled with pleural fluid, which creates a slippery surface that reduces friction as the lungs expand and contract during breathing. This ensures smooth movement within the thoracic cavity, minimizing discomfort and potential injury during respiration.

While gas exchange does occur in the lungs, it is not a function of the pleura itself. The pleura primarily aids in smooth lung movement, not in the exchange of gases, which takes place at the alveolar level. Similarly, while the pleura adds some support to the lung structure, its main role focuses on the lubrication necessary for efficient functioning during breathing. Preventing infections is related to the immune responses that the body employs, but the pleura does not serve a direct role in infection prevention. Instead, it is vital for maintaining the functional dynamics of the respiratory process.