The respiratory system is primarily for breathing. With it, we take the oxygen that every cell in our body needs. Respiratory tracts are also one of the barriers preventing contamination.
The venous system of the legs is made of veins embedded deeply and the surface ones embedded just under the skin - thin and delicate. Most circulatory dysfunctions lead to blood.
Water in the body is extremely important for the proper functioning of organs. Water supports the cleansing of the body by eliminating toxins in the urine, transports nutrients to each.