Liver vein. Coloured scanning electron micrograph (SEM) of a section through liver tissue showing a branching vein. Numerous capillaries, veins and arteries supply and remove blood for the liver. The structure of the liver allows the blood to percolate through the tissue. At any one moment, the liver holds over 10 percent of the body's blood supply. Magnification: x300 when printed at 10 centimetres wide.