国人胎儿十二指肠的组织发生

TISSUE DEVELOPMENT OF DUODENUM OF CHINESE FETUS

用引产的１４周～３６周新鲜胎儿标本１３８例，取十二指肠分上部、降部和下部三段石蜡切片，光镜观察组织发生。结果表明：１４周肠壁已有四层，厚１００μｍ～１５０μｍ，绒毛和肠腺短小，其上皮均由柱状细胞组成。１５周绒毛上皮和肠腺内出现少量的杯状细胞。１６周见环形皱襄。１７周～１８周上部出现十二指肠腺。１９周～２０周绒毛增宽和加长，中轴内见少量平滑肌细胞，降部和下部均出现十二指肠腺。２１周粘膜上皮的杯状细胞和粘膜下层的十二指肠腺增多。２２周壁厚６００μｍ～７５０μｍ，绒毛呈叶状，粘膜肌成薄层，十二指肠腺开始有分泌特征。２３周～２５周绒毛内可见中央乳糜管，肠腺底部见少数潘氏细胞。２６周后十二指肠的组织结构特点逐渐与成人近似。

induced fetus of 14～36 weeks were examined. Paraffin sections of the duodenumof these fetus were done.Histogenesis of the duodenums was observed with light microscope.The re-sults showed that the wall of the duodenum composed of four lays,100～150μm thick,the villus and in-testinal glands are shorter and them epithelium composed of columnar cell in 14th week,a few gobletcell appeared in the epithelium and intestine glands of the tunica mucosa in 15th week,the plica wasfound in 16th week,duodenal glands appeared in the pars superior duodeni from 17th to 18th weeks,length and width of villus increased,smooth muscles appeared in the centre of villus,duodenal glands ap-peared in the pars descendensand and pars inferior duodeni from 19th to 20th weeks,goblet cells of ep-ithelium of the tunia mucosa and duodenal qlands of submucosa increased in 21th week than before,thewall of duodenum 600～750μm thick,the villis are leaf-sharped and muscularis mucosa has layered,duodenal glands have the feature of mucosa gland in 22th week,certral lacteal and Paneth cells appearedfrom 23th to 25thweeks,tissue structure of duodenum of the fetus in similar to that of the adult after25th week.