|—n , pl pleurae|
|1.||the thin transparent serous membrane enveloping the lungs and lining the walls of the thoracic cavity|
|2.||the plural of pleuron|
|[C17: via Medieval Latin from Greek: side, rib]|
pleura pleu·ra (plur'ə)
n. pl. pleu·rae (plur'ē)
The thin serous membrane that envelops each lung and folds back to make a lining for the chest cavity.
|pleura (plr'ə) Pronunciation Key
Plural pleurae (plr'ē)
A membrane that encloses each lung and lines the chest cavity.
membrane lining the thoracic cavity (parietal pleura) and covering the lungs (visceral pleura). The parietal pleura folds back on itself at the root of the lung to become the visceral pleura. In health the two pleurae are in contact. When the lung collapses, however, or when air or liquid collects between the two membranes, the pleural cavity or sac becomes apparent (see pleurisy). There are actually two pleural cavities, the right and the left; each constitutes a closed unit not connected to the other. The glistening surface of the pleura is made up of a sheet of flat cells, the mesothelium, which covers an underlying layer of loose elastic tissue. The pleura exudes a thin fluid that keeps it moist and lubricated.
Learn more about pleura with a free trial on Britannica.com.