成年牦牛肺动脉的显微结构观察

Microstructural observation on pulmonary artery in adult yak

通过HE和Verhoeffe’s Van Gession染色法观察了成年牦牛肺动脉的组织结构，并用Image-Pro Express软件测算肺动脉中膜肌层的厚度，分析了肺动脉结构特性与高原低氧适应性的关系。结果表明，肺动脉的血管分支多数内、外弹性膜清楚；中膜和外膜的结构因管径不同而有差异，管径较大的血管中膜平滑肌和弹性纤维分布较多，外膜胶原纤维含量多，管径较小的血管中膜平滑肌和弹性纤维分布较少，外膜胶原纤维含量较少。肺动脉平滑肌含量丰富，直径17μm的血管中仍有平滑肌。肺动脉的性质多为肌性动脉和弹性动脉，伴行的多为终末细支气管以上的分支。肺动脉中膜肌层占血管外径的百分率（MT）变化幅度很大（1.89％-39.47％），其平均值为12.66％。证实成年牦牛的肺动脉富含平滑肌，即平滑肌相对增生变厚，低氧环境对牦牛肺有影响，肺动脉中膜肌层的少量增厚是对低氧的一种适应性结构。

To investigate the structure of adult yak＇s pulmonary arteries and the adaptability to the plateau,the histological structure of pulmonary arteries was observed by HE and Verhoeffe＇s Van Gession stainings,and the medial muscle thickness（MT） of pulmonary artery was measured by Image-Pro Express software. The results revealed that the internal and external elastic lamina in the pulmonary artery branches were clear. The structure of the tunica and adventitia had some variations with the increase of diameter. The tunica media in the larger arteries contained more smooth muscle and elastic fibers,and the adventitia media contained more collagen fibers. On the contrary, the smaller arteries contained less. Pulmonary arteries contained predominantly smooth muscle,till to the caliber of 17μm also had. The characteristic of pulmonary arteries in yak were almost the muscular and the elastic arteries. The pulmonary artery branches accompany the bronchus to the terminal bronchioles. The percentage of medial muscle thickness of pulmonary artery（MT） variation range was from 1.89% to 39.47% ,and the mean was 12.66%. It suggested that the pulmonary arteries had affluent smooth muscle, the hypoxia could also influence the lung structure of the yak. Medical muscle thickness of pulmonary artery less increased,which was adapted to the hypoxia.