人胎儿腭扁桃体隐窝上皮超微结构研究

ULTRASTRUCTURAL RESEARCH OF PALATINE TONSILLAR CRYPT EPITHELIUM OF HUMAN FETUSES

以电镜观察第４～８月龄人胎儿腭扁桃体的超微结构。第４月龄扁桃体上皮开始形成上皮芽并长入其下的结缔组织形成隐窝；隐窝上皮内出现淋巴细胞、交错突细胞、巨噬细胞等浸润。随胎龄增长浸润细胞数量增多并渐扩展到上皮表层。第８月龄胎儿隐窝上皮表层有少数Ｍ细胞，具有较一般上皮细胞为多的微绒毛并以胞质突起包绕和覆盖淋巴细胞。隐窝上皮下结缔组织中常见淋巴细胞、巨噬细胞等；毛细血管较丰富，有的血管紧贴上皮基膜分布。扁桃体固有层中初级淋巴小结在第４月龄已渐形成，此后增大并成熟，小结间弥散淋巴组织区窄小，可见呈立方内皮的毛细血管后微静脉。

The palatine tonsils of human fetuses aged from the 4th to the 8th months were studied by electron microscopy.In fetuses of about the 4th month,the epithelium of tonsil formed buds and grown into the beneath connective tissue to form crypts which were infiltrated by lymphocytes,interdigitating cells and macrophages. As a result of the continuous growth of the fetus,the infiltrating cells in the crypt epithelium increased in number and migrated to the superficial layer of crypt epithelium. There were a few of M cells with more microvilli than the surface epithelium cells at the surface of the crypt epithelium at the 8th month. Some lymphocytes were enclosed or covered by the cytoplasmic processes of M cells. There were many lymphocytes,macrophages and capillaries in the connective tissue beneaththe crypt epithelium. Some capillaries laid just beneath the basal lamina of the crypt epithelium. Theprimary lymphatic follicles appeared in fetal tonsilla at the 4th month. Then the follicles enlarged andmatured gradually. The interfollicullar areas were small and some of high-endothelial postcapillaryvenules were seen.