7.3.4 Lymphoid organs

. . Lymphoid organs Immune system of an organism consists of several structurally and functionally different organs and tissues that are widely dispersed in the body. The organs involved in the origin, maturation and proliferation of lymphocytes are called lymphoid organs (Fig. . ) . Based on their functions, they are classified into primary or central lymphoid organs and secondary or peripheral lymphoid organs . The primary lymphoid organs provide appropriate environment for lymphocytic maturation. The secondary lymphoid organs trap antigens and make it available for mature lymphocytes, which can effectively fight against these antigens.