成人房室结的超微结构

目的　探讨正常成人房室结的超微结构特征。方法　利用透射电镜观察正常成年人房室结的细胞及其构筑。结果　正常成人房室结主要由起搏细胞 (P细胞 )和心肌细胞构成 ,移行细胞较少。P细胞位于心肌细胞之间 ,成群存在。P细胞多为椭圆或柱状 ,细胞核相对较大 ,细胞器较少。移行细胞的形态和结构介于P细胞和心肌细胞之间。心肌细胞较多 ,相互平行排列 ,与P细胞无特化连接。结论　成人房室结的起搏细胞较少 ,普通心肌细胞较多 ,有心肌化的倾向。

Ultrastructure of Atrioventricular Node in Adult Human Heart

Objective To study the ultrastructure of the atrioventricular node in normal adult human heart.Methods The ultrastructure of the adult human atrioventricular node and its architecture were observed by transmission electron microscopy.Results The atrioventricular node was mainly composed of pacemaker(P) cells and myocardiac cells and less transistive cells. The number of transistive cells was fewer than those of P and myocardiac cells. P cells often clustered were located among myocardiac cells with elliptical or cylindrical shape and larger nucleus and less organells than others.The morphology of transistive cell is just in between myocardiac cell and P cell. Many myocardiac cells could be detected with paralleled arrangement and there was no special connection between P cells. Conclusion The working myocardiac cells are more than pacemaker cells in number in adult atrioventricular node with a tendency of transforming of atrioventricular node cells into working myocardiac cells.