Morphological Histological and Histochemical Studies on the Stomach of Prenatal Goat Capra hircus

Abstract

On perusal of literature it was found that very meager attention has been paid on the sequential newlinechanges in the development of ruminant stomach during various stages of gestation. Therefore, the newlinepresent study was designed. Macro and microscopic studies were conducted on the stomach of 36 newlinehealthy and normal goat embryos/ foeti of either sex. Age of the embryos/foeti was estimated by using newlineformula derived by Singh et al., (1979). Embryo/ foeti were grouped into I (0-50 days), II (51-100) and newlineIII (101-till term). At 38 days, all the four compartments of ruminant stomach were clearly discernible. newlineUndifferentiated stratified epithelium changed into stratified squmous and simple columnar epithelium newlineat 102 and 76 days of gestation in forestomach and abomasum, respectively. Microscopically, the newlinerumen, reticulum and omasum were distinguished by the appearance of papillae, crests and laminae at newline51, 60 and 38 days of gestation, respectively. Corial papillae first came in sight in reticulum and newlineomasum at 121 and 51 days of gestation, respectively. Muscularis mucosae could not be observed in newlinerumen till term. The orientation of smooth muscle fibers of tunica muscularis was inconstant newlinethroughout the gestation in forestomach. Earliest appearance of reticular fiber was noticed in blastemic newlinetissue of fore stomach (omasum) and abomasum at 44 and 38 days of gestation, respectively. Collagen newlinefibers embarked in lamina propria and submucosa of rumen and fundic part of abomasum at 60 and 76 newlinedays of gestation, respectively. At 100 days of gestation, the elastic fibers were first debuted newlineconcomitantly in the wall of the blood vessel of omasum and abomasum. Four different types of cells newlinewere identified in fundic region of abomasum viz. undifferentiated, chief, parietal and mucous neck newlinecells. The number of undifferentiated cells was predominant. Parietal and chief cells emerged newlineconcurrently at 70 day and mucous neck cells at 82 days of gestation. The cytoplasm was eosinophilic newlineand basophilic in parietal and chief cell, correspondingly. Mucous neck cells were largest and confined newlineto neck region only. The pyloric gland contained undifferentiating, mucous secreting and sporadic newlineparietal cells. Well differentiated mucous secreting cells were noticed at 121 day of gestation. newlineGanglionic and supporting cells of nerve elements were found either in the subserosal tissue or in newlinebetween the muscle bundles of stomach throughout the gestation. Basal zone of epithelium showed newlineintense activity for PAS and lipid in forestomach. AMPS reaction was pronounced in most of the newlineepithelial cells of superficial zone. Intense Feulgen reaction was detected in nuclei of the epithelial cells newlineof basal zone. Smooth muscle cells and blood vessels exhibited weak reaction for alkaline phosphatase newlineenzyme. Surface epithelium and glandular blind ends of pyloric abomasum revealed intense reaction newlinefor PAS and AMPS. Cell boundaries, parietal cells, smooth muscle cells, blood vessels and nerve cells newlineshowed intense reaction for lipid. At term abomasum was largest and omasum was the smallest newlinecompartment. Macroscopically and microscopically the wall of omasum was thickest among all the newlinecompartments. Statistical analysis of data revealed that all biometrical parameters of fore stomach newlineincreased significantly with the advancement of age and were highly significantly correlated with each newlineother. Micrometrical analysis of different strata of fore stomach showed that the thickness of propria newlinesubmucosa, tunica muscularis and serosa was highest in omasum followed by reticulum and lastly the newlinerumen. However, the thickness of epithelium was found to be maximum in reticulum, followed by newlinerumen and lastly the omasum. From the above study it can be concluded that the organogenesis and newlinehistogenesis of non glandular as well as glandular stomach was almost completed in prenatal life. newlineHowever, to become functional the stomach still required more time as the process of keratinization in newlineforestomach and differentiation of different cells of fundic and pyloric parts of abomasum were yet to newlinebe completed. newline