中华鳖消化系统的组织学研究

中华鳖消化系统主要由消化道和消化腺组成．消化道包括口咽腔（前部为口腔、后部为咽腔）、食道、胃、小肠、大肠；消化腺包括肝脏和胰脏．消化道管壁除口腔外，其余由粘膜层、粘膜下层、肌层和浆膜层组成．不同部位的消化道管壁肌层厚度有差异，胃壁最厚，食道和小肠壁其次，大肠壁最薄．中华鳖口腔和食道上皮由两层细胞组成，底层为扁平不规则的基细胞，表层为长形的粘细胞，这部分上皮还特化成具水呼吸功能的绒毛突起；胃、小肠和大肠上皮均为单层柱状上皮．肝脏中贮脂细胞发达并含大量深色颗粒；胰脏泡心细胞和胰岛均不发达

A Histological Study on the Digestive System in the Trionyx Sinensis Wiegmann

The degestive system of Trionyx Sinensis Wiegmann is defferentisted into the gastrointestinal tract and the digestive glands. The former consists of the buccal phaxyngeal cavity, the esophagus,stomach,small intestine and large intestine;the latter consists of the liver and pancreas. The digestive tube from the esophagus through the large intestine is made up of four concemtric layers:the mucosa,the submucosa,the musculars,and the serosa.The thicknesses of the muscularis are different according to the different parts of the tract. The muscular layer of the stomach is the thickest and that of the large intestine is the thinest. The unique characteristics of the digestive system are that the mucosa of the buccal cavity and the esophagus consist of only two layers of cells, which are the basic cells with irregular shape and the mucosa cells with long shape containint a lot of mucous granules. These layers form many villi that have aquatic respirative function. The mucosa of the stomach, together with the small and large intestines,has a single layer consisting longer shaped cells. There are many fat-storing cells containing a lot of dense granules in the liver, Which is rarely seen in other kinds of animals. The centro-acinar cells and islet of Langerlans of pancreas are poor developed