Histomorphological study of spleen in post –hatched Japanese quail (Coturnix coturnix Japonica)

The present research was conducted to study age wise histomorphological changes in spleen of post-hatched Japanese quail of one to four week of age. The spleen was ensheathed by connective tissue capsule of uneven thickness and was composed of unequally distributed collagen, reticular and elastic fibres with few muscle cells. The thickness of capsule, distribution and arrangement of splenic capsular components varied with the advancement of age. Connective tissue trabeculae were poorly developed in all age group of birds. Splenic parenchyma was composed of indistinctly demarcated white pulp and red pulp in the network of reticular cells and reticular fibres. In all age group of birds, the tissues of white pulp was diffusely scattered and was associated with parenchyamal vasculature. The white pulp was subdivided in to periarterial lymphatic tissue, perivenous lymphatic tissue, peroiellipsoidal lymphatic tissue and ellipsoids. The sizes of periarterial lymphatic tissue and perivenous lymphatic tissue increase with the age. Ellipsoids were round to oval structures composed of one to five concentric layers of reticular cells with few lymphocytes in network of reticular and collagen fibres around the penicillar capillaries. Age wise progressive increase in the number of macrophages was recorded in the periellipsoidal lymphatic tissue. The red pulp was less capacious at all stages of age and composed of cords and sinuses in the network of reticular cells and fibres.