Lung

[AS., lunge, lung]. The organ of respiration, in which the impure venous blood is oxidized by the air drawn through the trachea and bronchi into the air-vesicles. There are two lungs, a right and a left, the former usually consisting of three, the latter of two lobes. The lungs are situated in the thoracic cavity, and are enveloped by the pleurae. At the root or hilum the bronchus and its arteries, and the pulmonary artery and nerves enter, and the pulmonary and bronchial veins and lymphatics leave. The lung proper consists of minute air-vesicles held in place by connective-ti ue trabecule. Capillaries t the walls of the air-vesicles and bring the circulating blood in close proximity to the air. The average weight of the adult right lung is 22 ounces; that of the left 20 ounces. L.- fever, croupous pneumonia. 373