Functional Cytology Study Of Trionyx's Digestive Tract

Funchonal cytology of Trionyx's digestive traCt was Studied using ligh and electronmicroscope. immunal cytOchemiStry and sPecial stanjng. The funtion includes digeshon,absorption, respitalion, endocrine secretion and mucous immunology It was shown that themorphological mCtUe, diAnbution of vallous cell and ultraStwhon were different frommammai and avian. and not the same as other aquaic ndals.There was no gland in Trionyx's esophagUs. Over ten longitudinal folds were formedon the mucous sdse of the esophagUS. The epithelium was lined with tall colunmar cells.Thin wall intraePithelial caPilleq could be seen. Seven to nine longitudinal fOlds also couldbe seen in the cavity of stomacly the sdse of which was diStributed numrous gastric pits.The cardiac, fundus and Pyloric of stomach couldh't be dishngUished. Mucous epitheliumof stomach was single columnar and laxnina POrpria was filled with piPe-shaPed glands.There was one kind of glandular cel1s, Which was characterized as the morphology of bothparietal cell and chief cell. Undr electron microscoPe, deVloPed intraCellular canaliculusand numerous microvilIi were seen at the apex of the gland cell. The ventral of the cell wasfilled with mitochOndria and a lop number of Pepsiogen granular The smal intestine waslong, with conspicuous striated border In the villi there was not central laCteal, but acaPillary There were no any intestine glands and duOdenum glands in the Whole intestinumangUta. Differed from other boals, T/ionyx 's small inteshne mucous epithelium wasstratified columnar cells. Under the e1eCtrn ndcroscope. in the ePithelium ther weremainly tall columnar absorptive cell, between Which were many globet and endocrine cell.Someimes apoPtosis absorPtive cells could be seen. Large intestine was very short withmore and shorter fOlds. There were no Ancrovilli ProjeCted from the sche of epithelialcells. At the apex of the cytoplasm there were nurnerous mucous granular No glands wereseen in lnye intestine.CelI junctions were clear observed at the aPex flank betWen epithelial celIs of thegaStrointestinal traCt. The junedons were more tyPical in small inteStine than any othersechons of the digestive tract. However, sPaCe of ventral junctions between the cells wasconsPicuous. LymPhocytes's going through the epithelium was facilitated by the broadiniCrcellular space in the dismal rmall inteStine and larg intestine. DeveloPed folds, villiand microvilli on the surface of the epithelium increase surface of absorptive largely. Therefore, efficiency of digestion, absorption, endocrine secretion and mucous immunology was raised.Endocrine cells such as argyrophilic cells, 5-hydroxytryptamine (5-HT) cells and gastrin cells were distributed in mucous and glandular epithelium of the digestive tract. The amount of endocrine cells was most in the glandular epithelium of stomach and was more in small intestine than that of large intestine and esophagus. There were two types of endocrine cells, namely open type and closed type, which suggested that style of secretary of endocrine cells in Trionyx's digestive tract was various.There were more or less macrophage and mast cells in the lamina porpria connective tissue in Trionyx's digestive tract. No microfold cells and lymphatic nodule were found in its digestive tract, which was different from mammal and avian. There were intraepithelial cells (IEL) and lamina porpria lymphocytes (LPL) in the mucous epithelium. The amount of these cells increased from the proximal part to distal part of the digestive tract. IEL lied in the broad intercellular space. They were often out of shape when migrated, even lymphocytes with integrated structure were observed in the intestinal cavity. Most of the LPL were T-lymphocytes, and the minority were B-lymphocytes. In addition, there were some plasma cells.In addition to IEL, two types of intraepithelial plasma cells were observed in the intestinal mucous epithelium. One type was with dilated rough endoplasmic...