皱纹盘鲍消化系统的组织学研究

Histology of Digestive System in Haliotis discus hannai

利用光学显微镜观察研究了皱纹盘鲍的消化系统的组织学结构 .结果表明 :鲍的消化系统是由消化道 (口区、食道、嗉囊、胃盲囊、胃、肠、直肠、肛门 )、消化腺 (肝胰腺 )组成 .鲍的唇上皮由单层柱状细胞构成 ,细胞内充满着色素颗粒 ,唇内有纵横交错的肌纤维 ,其间有许多神经纤维分布 .其齿舌比较发达 ,齿舌囊的腹面正中线及其两侧分别有极发达的横纹肌肉块 .两侧的肌肉与包围齿舌软骨的肌肉群相汇合 ,其中绝大部分为纵肌 ,亦有少量环肌或斜肌 ,有利于摄食 .食道、嗉囊、胃盲囊、肠、直肠的结构基本相似 ,均由粘膜、粘膜下皮、肌层、外膜构成 ,与高等动物的类似 .肠粘膜下层发达 ,呈皱褶状向腔内突出 ,增大消化吸收的面积 .直肠的肌层发达有利于排遗 .鲍的消化腺主要由肝胰腺组成 .最外面为肝被膜 ,由单层立方上皮及其内的环肌层、结缔组织等构成 ,在结缔组织内含有小血窦 .肝小叶中的腺细胞交替进行分泌活动 .在分泌的细胞基部偶而可发现 1至几个染色较深的圆形细胞 ,核较大 ,内含 1个圆形核仁 ,我们称之为胚细胞 ,它可以补充分泌细胞的减少 .

This paper reported the histological st ru cture of the digestive system in Haliotis discus hannai.The study indicates that the digestive system of Haliotis discus hannaicomprises digestive trac t and digestive gland-hepatopancreas.The lip of Haliotis discus hannaiconsists of simple columnar epithelium in which there are many pigmeny granules,and there also many crisscross muscles and nervous fibres including some small blind tubules(foot gland).They have well de veloped radula with vertical strong striated muscles on their both sides,which a re closely connected with the muscles surrouding the radula cartilage.The digest ive tract from oesophagus to rectum have almost the same structure,they are comp osed of tunica mucose,tunica submucosa,tunica musclons and tunica adventia.But t here are some differences in different parts.Tunica submucosa of intestines is w ell developed.There are lots of corinkles on inner tunica mucosa of intestines.T he muscle of rectum is very strong.The digestive gland of Haliotis discus hann aiis mainly hepatopancreas,the gland cells in liver leaflets secrete alternat ively.Sometimes we can find one or several round deep dyed cells whose nuclei ar e relatively big and we call them empryo cells.They can make up for the shortage of other type of secreting cells.