日本鳗鲡消化系统的形态学及组织学研究

Morphology and Histology Studies on the Digestive System of Japanese Eel, Anguilla japonica

利用解剖学和组织学显微技术对日本鳗鲡(Anguilla japonica)的消化系统进行形态学及组织学研究。结果显示,日本鳗鲡消化道由口咽腔、食道、胃、小肠和直肠组成。口咽腔较大,黏膜上皮为复层扁平上皮,内含较多的杯状细胞。食道、胃及肠均由黏膜层、黏膜下层、肌层和浆膜层构成。食道短,黏膜上皮包括复层扁平上皮和单层柱状上皮。胃膨大,呈Y形,由贲门部、胃体部和幽门部组成,盲囊部发达。胃壁黏膜为单层柱状上皮,胃腺位于胃体部。肠道短,包括小肠和直肠,由前向后杯状细胞和黏膜褶皱不断减少。消化腺包括肝脏和胰脏,肝小叶分界不明显,肝细胞内脂肪滴明显。胰脏包括外分泌部和内分泌部,外分泌部由许多腺泡组成,胰岛散布在外分泌部内。

The morphology and histology structures of the digestive system of Japanese eel,Anguilla japonica were studied by using the anatomy and light microscope.The result showed that the digestive tract in A.japonica was composed of buccalpharynx cavity,esophagus,stomach,small intestine and rectum.The buccal-pharynx cavity was large,and its mucosa was composed of stratified squamous epitheliums with some goblet cells.The esophagus,stomach and intestine were composed of the mucosa,submucosa,muscularis and serosa layers.The esophagus was short,and stratified and simple columnar squamous epitheliums were identified.The stomach was expanded,Y-shaped,and composed of cardia,body of stomach and pylorus,and the gastric caecum was conspicuous.The stomach mucosa was comprised of simple columnar squamous epitheliums and the stomach gland was located in the body of the stomach.The intestines was short and included the small intestine and the rectum.From foregut to hindgut,the number of goblet cells and intestinal villus reduced gradually.The digestive glands were composed of the liver and the pancreas.The liver lobule was inconspicuous,but its hepatic cells were rich in fat.The pancreas was divided into the exocrine section and the endocrine section.The exocrine section of the pancreas was consisted of many pancreatic acinar cells.The pancreas islets were located in the exocrine section.