The lymph node is a small bean-shaped object which factors in the body's immune system. Lymph nodes clean out substances that travel through the lymphatic fluid, and they contain white blood cells that are the body's defense when fighting off ailments. There are many lymph nodes found throughout the body.
They are connected to other lymph vessels. Clusters of lymph nodes are located in the neck, underarm, chest, abdomen, and groin. There are about 20-40 lymph nodes in the underarm. Lymph nodes carry fluid, nutrients and waste material between the body tissues and the bloodstream.