包绕在肺脏表面的胸膜称脏层胸膜，被覆于胸壁内面的胸膜叫壁层胸膜。脏、壁层胸膜之间构成的腔隙称胸膜腔。正常情况下胸膜腔约有15毫升的微量浆液，在呼吸运动中起润滑作用，其产生和吸收的速度、数量基本相等并保持动态平衡。多种疾病可使胸膜产生液体增多或吸收减少，使胸 The pleura called the visceral pleura wraps around the surface of the lung and the pleura called the parietal pleura that is coated on the inside of the chest wall. Dirty, parietal pleura constitute the cavity between the pleural cavity. Under normal circumstances the pleural cavity about 15 ml of trace slurry, breathing in the lubrication play a role in its production and absorption of the speed and quantity are basically the same and maintain a dynamic equilibrium. A variety of diseases can increase pleural fluid production or reduce absorption, so chest