definition lymphatic system
View full size image. The lymphatic system is a network of tissues and organs that help rid the body of toxins, waste and other unwanted materials. The primary function of the lymphatic system is to transport lymph, a fluid containing infection-fighting white blood cells, throughout the body.The lymphatic system primarily consists of lymphatic vessels, which are similar to the circulatory system's veins and capillaries.he primary function of the lymphatic system is to transport lymph, a fluid containing infection-fighting white blood cells, throughout the body. The lymphatic system primarily consists of lymphatic vessels, which are similar to the circulatory system's veins and capillaries.