Liver Anatomy

The liver is located in the upper right-hand portion of the abdominal cavity, beneath the diaphragm, and on top of the stomach, right kidney, and intestines. Shaped like a cone, the liver is a dark reddish-brown organ that weighs about 3 pounds. There are 2 distinct sources that supply blood to the liver, including the following: (1) Oxygenated blood flows in from the hepatic artery, and (2) Nutrient-rich blood flows in from the hepatic portal vein.

The liver holds about 570 mL (13%) of the body's blood supply at any given moment. The liver consists of 2 main lobes. Both are made up of 8 segments that consist of 1,000 lobules (small lobes). These lobules are connected to small ducts (tubes) that connect with larger ducts to form the common hepatic duct. The common hepatic duct transports the bile made by the liver cells to the gallbladder and duodenum (the first part of the small intestine) via the common bile duct.

Infections, alcohol and fat build-up can cause scarring in the liver thus changing the anatomy. When sufficiently advanced, antomic changes may be picked by imaging tests.

Liver Function

The liver regulates most chemical levels in the blood and excretes a product called bile. This helps carry away waste products from the liver. All the blood leaving the stomach and intestines passes through the liver. The liver processes this blood and breaks down, balances, and creates nutrients. It also metabolizes drugs into forms that are easier to use for the rest of the body or that are nontoxic. More than 500 vital functions have been identified with the liver.

When the liver has broken down harmful substances, its by-products are excreted into the bile or blood. Bile by-products enter the intestine and leave the body in the form of feces. Blood by-products are filtered out by the kidneys, and leave the body in the form of urine.

Scarring in the liver can lead to dysfunction. However, the liver regenerates and the body increases blood flow to the liver to get more function out of the remaining liver. Only quantitative liver function tests can measure the combined effect of scarring, regeneration and increased blood flow.