Also called the
lymphatic system, it is comprised of
lymphatic vessels that run throughout the body (with the largest
vessel being the
thoracic duct, which collects a large portion of the body's lymph); lymph nodes, located in the neck, armpit, groin, and inside the center of the chest and abdomen; the tonsils and adenoids, which are collections of lymphoid tissue similar to lymph nodes; and the spleen and thymus, which are lymphoid organs.