鸡胚心脏外形变化及心外膜的发生

本研究用扫描电镜、透射电镜和光镜,观察了早期鸡胚心脏发生的外形变化及心外膜的发生。1.心脏发生经历2个阶段,首先是心脏的成襻过程,心管表面的一定部位出现沟,沟相应部位内面出现嵴。心襻的完成,标志着心脏各部原基的确立。第2个阶段是心脏各部原基的进一步分化,包括心腔内部的分隔及心脏各部位置的变化。心房与心锥的移位,可能是受左右心室移位的影响。2.心外膜片并非由心肌外层原位分化,而是由静脉窦处的间充质细胞增殖,并迁移覆盖在心肌层表面形成。

MORPHOGENESIS OF THE HEART AND THE FORMATION OF THE EPICARDIUM OF CHICKEN EMBRYO

The morphogenesis of the heart and the formation of the epicardium were studied with SEM, TEM and light microscopy. The results are as follows:1. There are two stages in the development of chicken heart: First is the formation of cardiac loop. In certain places, the sulcus appears outside, and the cresta appears inside during this stage. The formation of the cardiac loop indicates the establishment of the anlagen of the heart; Second is the differentiation of the anlagen, including the septation of the heart and the shift of each part of the heart. The shift of the atrium and the conus results from the shift of the right and left ventriculum. 2. The epicardium is not differcntiatcd from the myocardium, but formed from the mesenchymal cells which proliferate in front of the sinus venosus. These cells migrate and cover the entire surface of the myocardium.