Liver lobule. Light micrograph of a cross section through a liver lobule. The liver's main cells, hepatocytes (pink), are arranged into lobules. Each lobule has a central vein (white circle, upper left) which drains blood into the hepatic vein. The irregular hexagonal boundary of the lobule is defined by the portal tracts (white circle, lower right). Blood from the portal tracts flows towards the central vein between the hepatocytes. The liver has important functions in the body. These include waste detoxification, blood sugar regulation and the storage and metabolism of fats. Haematoxylin and eosin stained. Magnification x25 at 35mm size.