Why is the lymphatic system important? The lymphatic system is like the body’s waste processing plant. Water, blood cells, vitamins and other essential substances are returned to the heart for circulation to the tissues that need them. Bacteria and viruses are collected in the lymph nodes for the immune system to take care of. Toxins, damaged cells and other waste are recognized and processed by macrophages or moved along to be processed by the liver and kidneys. Image: ht