Lymphatic tissue: A part of the body's immune system that helps protect it from bacteria and other foreign entities. Lymphatic tissue is rich in lymphocytes (and accessory cells such as macrophages and reticular cells). The cells of the lymph are mostly lymphocytes. Associated lymphoid organs are composed of lymphoid tissue. They are referred to as mucosa‐associated lymphoid tissue (MALT). The nodules contain lymphocytes and macrophages that protect against bacteria . The bone marrow and thymus are primary lymphoid tissues and the sites of lymphocyte development. The lymph nodes, spleen, tonsils and Peyer's patches.Located in almost every tissue in the body, these vessels are interlaced among the arterioles and venules of the circulatory system in the soft connective tissues The lymphatic system is part of the immune system. With about 600 nodes and a vast network of vessels penetrating nearly every tissue. Secondary lymphoid organs, such as spleen, lymph nodes, Peyer's patches, and other mucosa-associated lymphoid tissues,