What do pleura do?

The Pleura

- It consists of two thin serous or synovial membranes.

- One of these layers covers the external surface of lungs (visceral pleura).

- The other lines the inner aspect of thoracic cavity including medial surface of rib cages (parietal pleura).

- The fluid filled space between lungs and thoracic wall acts as smooth layer to reduce friction with breathing/breathing in and out movement to allow lungs expand /relax freely during respiration or exchange of gases.