成年牦牛支气管动脉的组织结构观察

Observation of the histological structure of adult yak bronchial arteries

运用组织学方法对成年牦牛肺支气管动脉的组织结构进行了研究与分析,以探索支气管动脉对高原低氧环境的适应性结构。支气管动脉分布于支气管、胸膜、淋巴结、小叶间隔、肺动脉与肺静脉外膜、迷走神经鞘膜及气管腺周围,其中膜厚度占外径百分率MT(%)的均值为(33.30±11.03)%。肺外支气管动脉内皮下层无纵行平滑肌束,但进入支气管壁后其内弹性膜分叉并包绕纵行平滑肌束;中膜平滑肌结构较致密,外膜中含纵向螺旋状排列的胶原纤维束和弹性纤维。小支气管黏膜固有层中含有大量的支气管小动脉,数量可达(120±51)条/mm2。虽然黏膜固有层与外膜中的支气管动脉管径相差较大,但中膜平滑肌的厚度却很相近。可见,成年牦牛肺内支气管动脉管壁中的平滑肌含量非常丰富,是一种对低氧环境的适应性结构,表明低氧对牦牛肺有一定的影响。

Histological and morphometric methods were used to study the structure of histology and morphology of yak＇s bronchial arteries to investigate the structure of adult yak＇s bronchial arteries adapt to the plateau.The results showed that the wall of yak＇s bronchial arteries was distributed from bronchus to respiratory bronchioles and pleura,lymph nodes,interlobular septum,pulmonary arteries and veins,the perineurium of vagus and near the tracheal gland.The bronchial arteries from aorta lacked the longitudinal smooth muscle of subendothelial layer.But when they penetrated the bronchial wall,a subendothelial layer of longitudinal muscular fibres appeared in the intima.The elastic interna between splited and formed fibrillae which surround the longitudinal muscular fibres.There a strong inspissation of the media was prominent.External elastic lamina were unclear.The tunica adventitia included elastic fibers and collagen fibers,which were longitudinal winding.Many arterioles were contained in lamina propria mucosae of bronchus[（120±51）arterioles/mm2].Although the diameter of bronchial arteries in lamina propria did not coincide with in the tunica adventitia,their thickness of smooth muscle in media（MT%） was similarity.Therefore,it suggested that the bronchial arteries had affluent smooth muscle,the hypoxia could also influence the lung structure of the yak.Medical muscle thickness of bronchial arteries was adapted to the hypoxia.