What is the purpose of the pleura in the respiratory system?

The pleura serves an essential function in the respiratory system by providing lubrication that facilitates smooth lung movement during the respiratory cycle. This double-layered membrane, consisting of the visceral pleura (which covers the lungs) and the parietal pleura (which lines the chest cavity), creates a pleural cavity filled with pleural fluid.

This fluid reduces friction as the lungs expand and contract, allowing for effortless movement when we breathe. Without this lubrication, the surface tension would create significant resistance, transforming the mechanical process of breathing into a much more difficult task. Consequently, the pleura plays a critical role in ensuring efficient respiratory mechanics and overall lung function.