الفهرس 
Arabic Summary
Norhal Structure Of The Shall IntestineOnly 14 pages are availabe for public view
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Abstract
The first part of this investigation deals with the study of the pathological changes in the intestinal tract of 40 days old buffalo calves suffered from spontaneous diarrhea. For this purpose the small and large intestine from 23 diarrheic buffalo calves were obtained. Segments from the different intestial locations (1 x duodenum, 5 x jejunum,lx ileum,lx colon, lx caecum) were taken for histopathological and bacteriological examinations. The duodenal segments were further investigated by the transmission and scanning electron microscopy. The findings can be summarized as follows: br I. Escherichia coli was the principal cause of enteritis in these calves. In some calves Toxocara vitulorum was recovered from the duodenum and anterior jejunum. br 2. The histopathological lesions were mainly concentrated in the small intestine. The large intestine had a minimal score of lesions except in few cases. br 3. The histopathological lesions were atrophy and fusion of the villi, crypt hyperplasia, enterocyte necrosis and exfoliation, infiltration of the lamina propria of the villi witn neutrophils frequently with the formation of the crypt abscesses, other inflammatory cells including lymphocytes, eosinophils, and macrophages wire also present. The subepithelial blood capillaries were severely hyperaemic and those underlying the desquamated epithelial cells were directly exposed to the intestinal lumen. br 4. Transmission electron microscopy revealed that: br a. Dilatation of the tight junction between the surface epithelial cells, vesiculation of the microvillous border, swelling of the mitochondria, vesiculation and dilatation of the rough endoplasmic reticulum. Pyknotic cells were sporadically observed. Infiltration of the intercellular spaces with the intraepithelial lymphocytes. br b. The crypt epithelium showed swollen mitochondria, and dilatation of the rough endoplasmic reticulum. Near the basement membrane the crypt epithelium had lost the electron density of its cytoplastiic matrix as well as its cytoplasmic organelles and become filled with many free ribosoines. The apical part of the cytoplasm was occupied with a large number of membrane bound dense granules.