Liver: The liver is the largest internal organ of the body, weighing 3 to 4 pounds. It lies immediately under the diaphragm in the right upper abdomen. Its visceral surface is molded over the stomach, duodenum, gallbladder, hepatic flexure of the colon, right kidney, and right suprarenal gland. It is divided into right and left lobes. The right lobe of the liver has three parts called the right lobe proper, the caudate lobe, and the quadrate lobe. The small bile ducts within the liver (intrahepatic ducts) join to form two larger ducts which emerge from the under surface of the liver at the porta hepatis as the right and left hepatic ducts. The liver is one of the most vital organs in the body and plays a crucial role in the digestion and absorption of food. It breaks down protein, stores glycogen, iron, and vitamins, maintains the composition of the blood, and secrets products of detoxification. It continuously produces bile which is important in the digestion of fat and protein. The liver assists in keeping the amount of glucose (sugar) in the blood at a normal level. The liver manufactures plasma proteins. It destroys worn out erythrocytes and foreign material (phagocytosis). It produces heparin, an anticoagulant. It removes nitrogen from amino acids and converts it into urea. The urea then enters the blood stream and is carried to the kidneys where it is concentrated in urine and eliminated from the body. The liver secretes certain bile salts which aid in digestion. These substances pass through the bile ducts and may be stored in the gallbladder. With the stimulation of eating, these chemicals than pass through the cystic duct and the common bile duct to enter the duodenum at the ampulla of Vater. All of these ducts and the gallbladder are referred to as the "extra-hepatic biliary system." The lymphatic drainage from the liver is to hilar nodes, hepatic and periportal nodes below diaphragm, and to cardiac, pericardial, posterior mediastinal, and aortic nodes above the diaphragm.