人胚胎食管和肝的组织发生

HISTOGENESIS OF ESOPHAGUS AND LIVER OF HUMAN EMBRYO

以组织学和组织化学方法观察７周至足月胎儿食管和肝的组织发生。结果，７周胚胎食管上皮为复层柱状，ＰＡＳ反应强阳性；３月胎儿管腔纵行皱襞出现，管壁分层，上皮由复层柱状向复层扁平上皮过度；随着胚胎发育，食管上皮ＰＡＳ反应渐弱。７周肝脏，肝细胞成索状排列，见少许ＰＡＳ反应弱阳性的细胞。３月胎儿肝小叶、门管区出现。随着胚胎发育，肝细胞ＰＡＳ阳性程度渐增，足月胎儿肝细胞为强阳性。此结果可为教学、科研提供参考。

By means of histological and histochemicalmethods,we observed the histogenesis of esophagus and liver of human embrgo.The results showed that the esophagus' epithelium of the 7-week embryo is stratified columnar epithelium and PAS-reaction revealed theat epithelium are positive heavily.During the 3-month fetuse the esophagus shows vertical plicaes and layers of wall.The shape of the epithelium becomes stratified squamous from stratified columnar.PAS reaction decreased significantly in fetal esophagus with respect to the days of gestation.But the liver of fetuse are differect from esophagus.In 7-week embryo,PAS-reaction is only a very slight positive in some liver cells and is increased significantly in fetal livers with the development of the fetuse.Before birth,it becomes positive heavily.