细支气管的结构及病理生理特征支气管入肺后反复分枝,逐渐变细形成支气管树,末端称细支气管。每个细支气管所属的肺呼吸部称肺小叶(为锥体形,尖端向肺门,锥底向肺表面,肺小叶是肺的机能单位)。细支无软骨片,无腺体,平滑肌较发达,管腔直径1—2mm。管壁为假复层柱状纤毛上皮至单层柱状纤毛上皮、弹力纤维,平滑肌及少量结缔组织。平滑肌纤维间的弹力纤维与肺泡壁的弹力纤维相连结,因此细支管腔的保持与 Bronchial structure and pathophysiological characteristics After bronchial branches repeatedly into the lungs, tapering to form a bronchial tree, the end of said bronchioles. The lungs of each bronchiole bronchial lung called lung lobular (cone-shaped tip to the hilar, cone bottom to the lung surface, lung lobular lung function units). Fine cartilage fragments, no glands, more developed smooth muscle, luminal diameter 1-2mm. The wall of the pseudostratified columnar ciliated epithelium to a single columnar ciliated epithelium, elastic fibers, smooth muscle and a small amount of connective tissue. The elastic fibers between the smooth muscle fibers are connected with the elastic fibers of the alveolar wall, so the maintenance of the fine branch lumen and