Basic information | Respiratory tract | Lower respiratory system | Pulmonary and costal pleura

Pulmonary and costal pleura

The described bronchial tree is wrapped in two large "plastic bags." We refer to the internal covering as the pulmonary and the outer one as the costal pleura. The pulmonary pleura surround the lung, while the costal pleura sticks to the inside in the thorax. The space between these two coverings is vacuous and is covered with a fine liquid film. The two coverings can shift with respect to each other unhindered. Thus the lung can expand and then deflate again.