<P> The various functions of the liver are carried out by the liver cells or hepatocytes . The liver is thought to be responsible for up to 500 separate functions, usually in combination with other systems and organs . Currently, no artificial organ or device is capable of reproducing all the functions of the liver . Some functions can be carried out by liver dialysis, an experimental treatment for liver failure . The liver also accounts for about 20% of resting total body oxygen consumption . </P> <P> The liver receives a dual blood supply from the hepatic portal vein and hepatic arteries . The hepatic portal vein delivers around 75% of the liver's blood supply, and carries venous blood drained from the spleen, gastrointestinal tract, and its associated organs . The hepatic arteries supply arterial blood to the liver, accounting for the remaining quarter of its blood flow . Oxygen is provided from both sources; about half of the liver's oxygen demand is met by the hepatic portal vein, and half is met by the hepatic arteries . The hepatic artery also has both alpha - and beta - adrenergic receptors; therefore, flow through the artery is controlled, in part, by the splanchnic nerves of the autonomic nervous system . </P> <P> Blood flows through the liver sinusoids and empties into the central vein of each lobule . The central veins coalesce into hepatic veins, which leave the liver and drain into the inferior vena cava . </P> <P> The biliary tract is derived from the branches of the bile ducts . The biliary tract, also known as the biliary tree, is the path by which bile is secreted by the liver then transported to the first part of the small intestine, the duodenum . The bile produced in the liver is collected in bile canaliculi, small grooves between the faces of adjacent hepatocytes . The canaliculi radiate to the edge of the liver lobule, where they merge to form bile ducts . Within the liver, these ducts are termed intrahepatic bile ducts, and once they exit the liver, they are considered extrahepatic . The intrahepatic ducts eventually drain into the right and left hepatic ducts, which exit the liver at the transverse fissure, and merge to form the common hepatic duct . The cystic duct from the gallbladder joins with the common hepatic duct to form the common bile duct . The biliary system and connective tissue is supplied by the hepatic artery alone </P>

Where is kidney and liver located in human body