Center for Advanced Liver Diseases and Transplantation

Anatomy of the Hepatobiliary System

Not many people appreciate the importance and the intricacies of their liver until there is a problem with it. Weighing about three pounds, the liver is a production plant, a refinery, and a warehouse all in one organ.

It processes the various components in the food received from the intestines and removes toxins from the bloodstream.

This "manufacturing plant" also produces bile, a substance that is essential to the digestive process, as well as albumin and other important proteins required for normal clotting of the blood, certain hormones, and cholesterol.

The liver is also a storehouse for vitamins (such as vitamins A, D, E and K), minerals, and glycogen. Glycogen is converted into glucose by the liver, enabling the body to handle the call for quick bursts of energy. It stores iron, and helps transport fat stores as well.

Unlike any other organ in the body, a damaged liver can regenerate itself (as in the Promethean Greek legend), provided that there is no cirrhosis- an accumulation of scar tissue. The liver's ability to grow back is what enables surgeons to remove tumor-containing sections of the organ or to take a healthy section of the liver from a living donor for transplant. Several weeks after surgery, the liver grows back to its original size, but not its original shape.

The liver is located behind the lower right ribs. The organ is connected by ligaments to the diaphragm on its upper section, and on the left, to the stomach. The liver receives approximately 3-4 pints of blood every minute. Unlike other organs, which receive blood via only one artery, the liver receives blood from an artery (hepatic artery) and also a vein (portal vein). The liver has three primary sections, or lobes: right, left, and caudate. The right lobe is the largest lobe-accounting for approximately 3/5 th-2/3rd of the liver size.

The gallbladder is a pear-shaped sac, which stores the bile produced by the liver. The bile passes through a series of bile ducts, or passageways (similar to the drainage system in and out of a house), known collectively as the biliary tree. The bile continues its journey into the gallbladder, where it is stored in between the meals. When food enters the intestine, the gallbladder contracts and releases bile into the small intestine. There, the bile mixes with the food and further aids in digestion, especially of fatty foods.

Although not considered part of the hepatobiliary system, the location and function of the pancreas is closely associated with the bile producing and storing organs. The pancreas is a small organ located behind the stomach. The bile duct travels through the pancreas immediately before it enters the small intestine. Thus any problem in the pancreas (such as cancer, pancreatitis and cysts) that is adjacent to the bile duct often causes blockage of the bile duct and jaundice.

Many people are familiar with one of the roles of the pancreas, which is the production of insulin. But another function of the pancreas, performed by its exocrine gland, is to secrete pancreatic “juice” that also aids in the digestive process. Like bile, pancreatic juice is transported by ducts. Both the common bile duct and the pancreatic duct empty into the duodenum, part of the small intestine.