Pleura

Pleura is a serous membrane covering lungs and lining thoracic cavity.

Parietal pleura

Visceral pleura

 Pleural cavity.

The two layers are continuous with one another

They are in contact with one another, and the potential space between them is known as the pleural cavity.

The right and left pleural sacs are entirely separate from one another by the mediastinum

They only touch each other for a short distance in front; opposite the second and third pieces of the sternum