Which structure's function includes allowing pleurae to slide effortlessly during ventilation?

Which structure's function includes allowing pleurae to slide effortlessly during ventilation?

• A. Visceral pleurae
• B. Pleural cavity
• C. Parietal pleurae
• D. Left Lung

Answer: (B)

The pleural cavity is the space between the visceral pleura, which covers the lungs, and the parietal pleura, which lines the chest wall. Its primary function is to contain pleural fluid, a serous fluid that facilitates smooth movement of the pleurae during breathing. This allows the visceral and parietal pleurae to slide effortlessly against each other as the lungs expand and contract during ventilation. The presence of this fluid reduces friction and enables efficient respiratory mechanics, contributing to effective inhalation and exhalation.