Tissues and organs of lymphatic system • Composed of lymphatic vessels and lymphatics, cells, tissues, and organs. • Screen the tissues of the body for foreign antigens Lymphatic vessels- one way system that conduct lymph from tissues and returns it to circulatory system Lymph-Liquid similar composition to blood plasma. Comes from fluid leaked from blood into surrounding tissues. Lymphoid organs Primary lymphoid organs Redbone marrow Thymus Secondary lymphoid organs spleen Tonsils Mucosa- associated lymphoid tissue. Adaptive immunity- is the body’s ability to recognize and defend itself against distinct invader and their products.