Pleura

(plu' -rah). The serous mem brane which envelops the lung (P., Pulmonary), and, which being reflected back, lines the ental surface of the thorax (P., Costal). In biology: (a) the lateral portion of the integumentary segments of an arthropod. It lies between the tergum and sternum, and consists of the epimer on and epistemum; (b) one of the lateral tracts of the rachis of the lingual ribbon of gastropod molluscs. P. costal is. See P., Costal. P., Diaphragmatic, the reflection of the pleura upon the upper surface of the diaphragm. P., Parietal. Synonym of P., Costal. P., Pericardial, the portion of the pleura contiguous to the pericardium. P. phrenic a. Synonym of P., Diaphragmatic. P. pul monal is. Synonym of P., Pulmonary. P., Visceral. Synonym of P., Pulmonary.