A pleura refers to a serous membrane which folds back onto itself to form a two-layered membranous pleural sac. There are two pleurae: parietal pleura and visceral pleura.
The outer pleura called parietal pleura, and it is attached to the inner surface of the thoracic cavity. The inner pleura called visceral pleura, and it covers the surface of each lung and dips into the fissures between the lobes.
Keywords: pleura; pleura__; pleura+; pleurx