What is the primary role of the pleural lining?

The primary role of the pleural lining is to facilitate movement and reduce friction in the thoracic cavity. The pleurae consist of two layers – the visceral pleura, which adheres to the lungs, and the parietal pleura, which lines the thoracic cavity. This double-layered structure plays a critical role during respiration. As the lungs expand and contract, the pleural fluid between these layers allows for smooth sliding movements, minimizing friction. This action is essential for efficient breathing, as it enables the lungs to inflate and deflate seamlessly.

The other options do not accurately reflect the main function of the pleural lining. While structural support for ribs, fluid storage, and the production of respiratory surfactant are important functions in the respiratory system, they are not directly associated with the pleural lining's primary role. The pleura specifically focuses on facilitating lung movement and decreasing friction during respiration, making it vital for respiratory efficiency.