The liver is a vital organ in the human body and is present in vertebrates and some other animals. The liver is necessary for survival; a human can only last up to 24 hours without liver function.Fact: date=September 2008 It plays a major role in metabolism and has a number of functions in the body, including glycogen storage, decomposition of red blood cells, plasma protein synthesis, and detoxification. The liver is also the largest gland in the human body. It lies below the diaphragm in the thoracic region of the abdomen. It produces bile, an alkaline compound which aids in digestion, via the emulsification of lipids. It also performs and regulates a wide variety of high-volume biochemical reactions requiring very specialized tissues.

Medical terms related to the liver often start in hepato- or hepatic from the Greek word for liver, hēpar (ήπαρ).

Anatomy

The adult human liver normally weighs between 1.4 - 1.6 kilograms (3.1 - 3.5 pounds), and it is a soft, pinkish-brown, triangular organ. Averaging about the size of an American football in adults, it is both the largest internal organ and the largest gland in the human body.

It is located on the right side of the upper abdomen below the diaphragm anatomy. The liver lies to the right of the stomach and overlies the gallbladder.

Flow of blood

The splenic vein joins the inferior mesenteric vein, which then together join the superior mesenteric vein to form the hepatic portal vein, bringing venous blood from the spleen, pancreas, stomach, small intestine, and large intestine, so that the liver can process the nutrients and by-products of food digestion.

The hepatic veins of the blood can be from other branches such as the superior mesenteric artery.

Both the portal venules & the hepatic arterioles enter approximately one million identical lobules acini, likened to and changes in the size of chylomicrons lipoproteins of dietary origin brought about by the quantity & types of food fats.

Approximately 60% to 80% of the blood flow to the liver is from the portal venous system, and 1/5th of blood flow is from the hepatic artery.

Flow of bile

The bile produced in the liver is collected in bile canaliculi, which merge to form bile ducts.

These eventually drain into the right and left hepatic ducts, which in turn 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.

Bile can either drain directly into the duodenum via the common bile duct or be temporarily stored in the gallbladder via the cystic duct. The common bile duct and the pancreatic duct enter the duodenum together at the ampulla of Vater.