构成肺的基本单位是肺小叶,由3～5个腺泡所组成。腺泡系指终末细支气管及其所属各单位(包括呼吸性细支气管、肺泡管与肺泡囊)。小叶大小不等,界限一般清晰可见,相邻的肺小叶间有薄层结缔组织分隔,临床上,小叶性肺炎指肺小叶的病变,而肺气肿是发生在腺泡部位的病变。一、肺泡成人肺泡约有3～4亿。总面积约为80 The basic unit of the lungs is the lung lobules, composed of 3 to 5 acinar. Acinar refers to the terminal bronchioles and their affiliated units (including respiratory bronchioles, alveolar ducts and alveolar sacs). Leaflet size range, the boundaries are generally clearly visible, adjacent to the thin layer of connective tissue between the lobular lobes, clinically, lobular pneumonia refers to the lesion of the lung lobular, and emphysema is a lesion in the acinar site. First, alveolar adult alveoli about 3 to 400 million. The total area is about 80