Morphological and Histological Study of the Stomach in Local Rodent Species(Guinea Pig) Cavia Porcellus

Abstract

The study of stomach in adult male local guinea pigs rodents included the morphological description ,histometric measurments and histoarchitecture at the light microscope level by using Haematoxyline and Eosine stain methods.The results revealed that the stomach had C shaped with the presence of two curvatures and shallow angular notch. It is simple (unilocular) smooth and homogenous grossly  without  external demarcation limiting ridge (margo plicatus) between its devisions , white grayish in color and slightly transparent. Blood was supplied to the stomach by the coeliacomesentric  trunk.The microscopic examination revealed that the wall of the stomach show the characteristic four compartmant tunics : Mucosa , Submucosa , Muscularis externa and Serosa.The stomach regions were cardiac type (A, B) , fundic  and  pyloric .The mean thickness of tunica mucosa was the maximum in fundic region (110+10) and the minimum in cardiac region type A (13 + 2.7386). The mean thickness of tunica muscularis externa  was the maximum in pyloric region (67+ 4.4721) and the minimum in cardiac region type A(29.6 + 0.5477). Non keratinized stratified squamous epithelium  covers the tunica mucosa of cardiac region type A with visible stratum granulosum , while Simple columnar epithelium with gastric glands and pits covers the tunica mucosa of the other regions of stomach . Skeletal and smooth muscle fibers found in tunica muscularis externa of cardiac region type A ,while spiral ,circular  and longitudinal arrangement of smooth muscle fibers found in  tunica muscularis externa of the other regions of stomach. The simple tubular cardiac glands composed of predominate mucous secreting cells , mucous acinar cells found on the basal surfaces , few parietal cells, enteroendocrine cells and undifferenciated cells. The simple tubular fundic glands with shallow pits  composed of mucous neck cells, parietal cells which were predominantly present in the upper and lower half of the fundic glands , chief cells  and  enteroendocrine cells that found in the lower third  of each fundic glands. The long simple branched tubular pyloric glands with deep pits, composed  of predominantly mucous acinar cells along the leng of the frontal  and basal surfaces , randomly parietal cells,few chief cells  and  enteroendocrine cells.

Keywords:   stomach , local guinea pigs , histoarchitecture