Histomorphometrical and Histochemical studies on the glandular stomach [proventriculus] of Poonchi bird of Union Territory of Jammu and Kashmir

Histologically, proventriculus of Poonchi bird consisted of tunica mucosa, tunica submucosa, tunica muscularis and tunica serosa. Tunica mucosa was arranged in folds of variable height. Lamina epithelialis consisted of simple columnar epithelium. Tunica submucosa presented compound tubule-alveolar submucosal/proventricular glands which varied from round, oval, hexagonal or polymorphic lobules separated by connective tissue. Within each lobule, numerous glandular tubules and alveoli had radiating arrangement lined by cuboidal epithelium. Tunica muscularis consisted of three layers of smooth muscles. Tunica serosa consisted of loose connective tissue containing nerves and blood vessels. Thickness of tunica mucosa was 490.86 ± 43.47 µ. Tunica submucosa was 1641.16 ± 116.49 µ thick. Thickness of tunica muscularis was 427.99 ± 22.06 µ. The outer muscle layer was thickest (114.37 ± 9.81 µ). The thickness of tunica serosa was 83.68 ± 3.64 µ. Histochemically, the mucosal epithelial lining showed strong positive reaction to PAS-AB (pH 2.5). The glandular secretions were strongly positive to PAS. The epithelial lining of secretory ducts and secretory units of the compound tubule-alveolar glands showed strong reaction with both PAS stain and PAS-AB stain indicating the presence of both neutral and acid mucins. With PAS-AB stain, the cells towards the central cavity stained reddish purple whereas towards bottoms, cells were bluish indicating acidic mucins. Submucosal glands and tunica muscularis layer showed strong reaction for basic proteins. Cells of sub-mucosal glands showed moderate to strong reaction for lipids in supra-nuclear zone.