MORPHOGENESIS OF DUODENAL VILLI IN RATS / 解剖学报

During 14-17th days, the duodenum of the rat fetus was composed of stratified epithelium and peripheral mesenchyme. On 18th day, the mesenchyme began to protrude toward the basal aspect of the epithelium, resulted in the formation of primary villi. At the sametime, goblet cells and the primordia of intestinal glands appeared. The number of goblet cells,which located at the surface of the villi, increased gradually with the fetus age, whereas after birth the goblet cells decreased with the development and maturation of intestinal glands. From 19th day till 3-4 weeks after birth, the shape of villi changed continuously, and attained to the adult shape in 4th week.