Age related micro anatomical changes in stomach of Indian domestic pig (Sus scrofa domesticus)

Abstract

Stomach wall of domestic pig had four layers i.e., tunica mucosa, submucosa, muscularis and serosa in all four regions. Non-glandular region was lined by non-keratinized stratified squamous epithelium. In Group-I lymphatic infiltration appeared in diffuse form but in Groups II and III lymphatic nodules were scattered at oesophageo-cardiac junction. In cardiac region, gastric pits were wide in group-I, narrow in group-II and wide and shallow in group-III. Cardiac glands were simple, branched, coiled tubular glands whose branching increased up to 21st day piglet beyond which it ceased. Parietal cells increased in number in group-I but decreased in higher groups. Diffuse lymphatic infiltration was seen in group-I followed by lymphatic nodules in groups-II and III. Thick lamina muscularis comprised smooth muscle. Tunica submucosa with loose connective tissue and fat cells seen in group-III. Tunica muscularis consisted of inner circular and outer longitudinal layers of smooth muscle fibres and outer tunica serosa covered by mesothelium. In fundic region, mucosa exhibited rugae with gastric pits opening between them. Fundic glands were branched long tubular glands that increased in length with age and were closely packed together and had thin glandular portions compared to cardiac glands. Parietal cells, chief cells and mucous cells were present in all age groups. Mucous cells became predominant in groups-II and III. Lamina propria was a thin layer with irregular tubes of fundic glands. In pyloric region gastric pits deepened with increasing age from group I to III. Parietal cells were more in 6th day piglets and decreased in older animals.