鸡胚心内膜垫及室间隔的发生

本研究用扫描电镜、透射电镜、光学显微镜及组织化学等方法观察了早期鸡胚心脏发生中的心内膜垫及室间隔的发生过程,其结果如下: 1.心内膜垫的发生起始于内膜细胞的增殖,向心胶质内输送内膜垫细胞。内膜垫细胞分裂增殖向肌层方向移动。当出现内膜垫细胞的贮备层以后,表面的内膜细胞停止增殖。融合的内膜垫参与房室口的形成,其右侧结节向尾侧延伸与室间隔融合。 2.早期心内膜垫的心胶质中含有大量透明质酸,以一定的方向排列成“轨道”,内膜垫细胞沿“轨道”向肌层方向迁移并改变基质成分及排列方式。 3.肌性室间隔是心室壁分化形成的小梁在室间沟内侧聚集而成。室间隔背侧部与内膜垫右侧结节的下延部分融合,腹侧部与锥隔相延续。

THE MORPHOLOGICAL STUDY OF THE DEVELOPMENT OF ENDOCARDIAL CUSHION AND VENTRICULAR SEPTUM OF CHICKEN EMBRYO

The development of the endocardial cushion and the ventricular septum of chicken heart was studied with SEM, TEM, light microscopy and histochemical methods. The results are as follows:1. The development of endocardial cushion begins from the proliferation of the endothelial cells which form cushion cells when these cells enter the cardiac jelly. Cushion cells also proceed mitosis and migrate toward the myocardium, and the endothelial cells cease proliferation when the reserve layers of cushion cells were formed. The fused endocardial cushion participates in the formation of atrioventricular orifice, the right tubercle prolongs toward the ventricular septum and eventually fuses with it.2. The cardiac jelly of endocardial cushion contains a great deal of hyaluronic acid which arranges in "trails", pioneering cushion cells migrate along the "trails" and change the component and arrangement of the matrix.3. Muscular ventricular septum is formed by aggregation of trabeculae inside the interventricular sulcus. The dorsal part of the ventricular septum fuses with the lower part of right tubercle of endocardial cushion and the ventral part fuses with the conus septum.