Reaearch On Dgestive Tact Oganizational Sructure And Fnction Of Feshwater Panarian (Dugesia)

Platyhelminthes play an important role in the flashlite of planarian . Dugesia japonica Ichikawa et Kawakatsu,as the typical kind of this class, is the key point of modern research. planarian has powerful regeneration capacity, the regeneration research concerning planarian has entered the area of molecule biology and stem cell, this paper mainly concentrates on the structure of alimentary canal , the position and effect of some main digestive enzyme in planarian。The Dugesia japonica Ichikawa et Kawakatsu used in the experiment are collected from Shanxi xi'an qingling and Hebei province, belonging to the Platy helminthes ,Turbellaria, Tricladida ,Dugesia, Dugesia japonica.The pharynxes and guts of planarians are dyed buy H.E, and the transmissible electron microscope are used to research the ultrastructure of the pharynxes and enteric epithelium. The result shows that the epithelial cells in and out of the fauces are made up by syncytium, the passageway in cytoplasm and nucleus. Some muscle layer exists sc subcutaneous , and a large number of ducts that are found in the pharynxes have a great relationship with the pharynxes'activities that metabolize and produce new egesta. It's very clear to see the structure of the solenocyte lied in the pharynxes. The cells in the gut are monolayer columnar epithelium, using the electron microscope we can see the enterocyte are made up of two kind of cells,one is the cells that are heavy in electron-density and dyed deep, the others are on the contrary. The cells deep dyed don't projected into the lumen,and in the cells there are a lot of uncolored and light-color cells with different size;The light color cells'.free surface abnormity projected into the lumen,also including lots of uncolored and light colored cells. In the cells with light color we may see some phagosome of bacterium. Therefore,Dugesia japonica Ichikawa et Kawakatsu's enteric epithelium play an important role in the field of researching on the mechanism of action of phagocytes in human viscera. The Grimellus reduced silver experiment shows the structure of argyrophil masculine in Dugesia japonica。The result is, In enterocyte s , there are a lot of round vesicle-like structure witch are dyed in brown color,and a large number of black granules distribute in parenchyma tissue under the intestinal epithelium. So it can be sure that APUD system exist in the parenchyma tissue under the intestinal epithelium. Through the research that observe the fat which are dyed by SudanⅢ,we found that in the planarian enterocytes, there are a large amount of fat, which can apply food and energy when needed,and protect planarian by improving the softness of the body. With the experiment ACP staining ,large amount of lysosome are found in the planarian,that certificates that planarian have the ability of intracellular digestion and the endocytosis in the process of gut epidermis's digesting are proved by the existence of lysosome. lysosome can combine food vacuoles that are devoured by gut and then digest it. lysosome can immune the senile and lesion cells in planarian, planarian have set up the immunity ability in the process of evolution. Around the pharynx there are a lot of ALP,which is very important to the rebuilt of the pharynx and the across memirane transport of matter。Neural system also produce some incretion to regulate pharynx's activities indirectly,with the modulation of the across memirane transport by carbonic compound, AKPase regulate these incretion's excrete and transfer to keep stability and veracity. A small quantity of 5-HT immune active endocrine cells are found in planarian, mainly distribute in parenchyma around the gut. 5-HT can regulate the activities such as digesting , and help the neural system to take , digest and absorb food .