What are pleurae?

Pleurae are indeed the serous membranes that surround the lungs. These membranes play a crucial role in the respiratory system, creating a protective barrier that helps to reduce friction between the lungs and the chest wall during the process of breathing. The pleurae consist of two layers: the visceral pleura, which is in direct contact with the lung tissue, and the parietal pleura, which lines the chest cavity.

The function of the pleurae is important because they enable the lungs to expand and contract smoothly as air is inhaled and exhaled. Additionally, the pleural cavity, the space between the two layers, contains pleural fluid, which further facilitates movement and provides lubrication.

Understanding the role of the pleurae is vital for comprehending several respiratory conditions, such as pleuritis, where inflammation of the pleura may lead to pain during breathing. The other options refer to different structures or functions related to the respiratory or vocal system, but they do not accurately describe the pleurae themselves.