Definition of Pleura
Pleura is the membrane that covers the exterior surface of the LUNGS and lines the inside of the thoracic cavity.
The membrane has the consistency of wet tissue paper and appears to cling to the lungs.
The pleural space (thin area between the two layers of pleura) protects the lungs from contact with other structures within the thoracic cavity, and contains a very small amount of fluid that reduces friction with BREATHING.
For further discussion of pulmonary structure and function please see the overview section “The Pulmonary System.”