鸡胚房间隔与第二孔的形态发生

MORPHOGENESIS OF ATRIAL SEPTUM AND FORAMINA SECUNDA IN CHICK EMBRYO

目的探讨心脏房间隔与第二孔形态发生机制。方法按Ｈａｍｂｕｒｇｅｒ和Ｈａｍｉｌｔｏｎ分期法，选用第２０～２６期鸡胚，用显微解剖术和扫描电镜方法，观察房间隔与第二孔的形态发生过程。结果房间隔尚未与心内膜垫融合前，房间隔中央部上皮处出现小孔，小孔随着长突起状细胞的出现而增多。筛状的第二孔形成后，长突起状细胞减少并消失。结论第二孔形成不是被动破裂的过程，在形成的早期可能与长突起状细胞有密切关系。

Objective\ To study the morphogenesis of atrial septum and foramina secunda.Methods\ Based on Hamburger and Hamilton staging, chick embryos were selected.The formation of atrial septun and foramina secunda were observed with microdissection and SEM.Result\ Before the fusion of the atrial septum with the endocardial cushion,some small perforations on the epithelia appeared in the central part of atrial septum.These perforations increased with appearance of the long process cells.When the formation of sieve foramina secunda,the cells with long processes were decreased and gradually disappeared.Conclusion\ The formation of foramina secunda is not a process of passive breaking.The cells with long process might be closely related with the early formation of foramina secunda.