Result: at 8-week embryo, trachea consists of 2-3 layers of stratifiedcolumnar cells and mesenchyme around the cells, the reaction of PAS of epithelium was positive.
结果：8周的胚胎，气管壁由2 3层复层柱状上皮细胞及外周的间充质构成，上皮细胞的PAS反应为阳性。
2
The gland epithelium was irregular pseudo-stratified ciliated columnar epithelium which consist a lot of secretory cells, fewer ciliated columnar cells, and basilar cells.