The white blood cells or lymphocytes produced by these lymph nodes kill bacteria and viruses entering the body. Lymph nodes are very small organs, only about 1-2 cm in size and are found as a network throughout the body.hat Are Lymph Node, Locations And Diseases. Humans generally have immunity against pathogens and accidental infections that is owed to the presence of lymph nodes which form a part of the lymphatic system. They behave like mechanical filters and kill and eliminate microbes present in the blood stream.