扬子鳄胚胎胃的组织发生

THE STOMACH HISTOGENESIS OF ALLIGATOR SINENSIS

以２４例扬子鳄（Ａｌｌｉｇａｔｏｒｓｉｎｅｎｓｉｓ）胚胎为材料观察胃壁及胃腺发生过程。孵化第１０ｄ，胃与食管出现形态差异。第１２～１６ｄ胃上皮细胞加快分裂增殖，细胞层次明显增多。胃上皮分化以贲门区及胃底部较早，胃体及幽门区较迟。中胚层间充质在第１２～１８ｄ逐渐向胃上皮周围聚集并在第２４～４０ｄ先后形成环肌层、斜肌及纵肌层。第４６ｄ固有膜、粘膜肌及粘膜下层明显。胃底腺、幽门腺及贲门腺于第４０ｄ出现腺芽，第４６ｄ分别形成分支管状腺及单管腺。第５２ｄ腺腔内均有分泌物出现。本文讨论了扬子鳄胃组织发生的特点。

In this paper,we used 24 embryos between the 2nd and 52nd day of incubation to observe the histogenesis of stomach of Alligator sinensis. The stomach was morphologically different from esophagus at the 10th day of incubation. During the period of 12-16th days of incubation,active proliferation of gastric epithelial cells had resulted in marked increase of cell layers. The epithelial difterentiation at gastric fundus and cardiac region was earlier than those at gastric body and pyloric region.The mesodermal mesenchyme gradually gathered around the gastric epithelium during the period of 12-18th days of incubation,and differentiated to form circular,oblique and longitudinal layers of muscularis externa during the period of 24-40th days of incubation. The lamina propria,muscularis mucosae and submucosa were visible at the 46th day of incubation. The glandular buds of gastric fundus,cardiac and pyloric glands appeared at the 40th day of incubation and formed branched and simple-branched tubular glands respectively at the 46th day of incubation,At the 52nd day of incubation,secretory products are found in all glandular lumens. This paper discussed the characteristics during stomach histogenesis of Alligator sinensis.