The liver is a large and vitally important organ in the abdomen. It can be thought of as a living laboratory and a chemical plant. More than hundred different processes are known to take place in it. It is reddish brown in colour and located in the upper abdominal cavity beneath the diaphragm and ribs.
The liver is basically concerned with the digestion of food, excretion, storage and conversion of food materials, the regulation of the composition of blood and the destruction of poisonous substances. If it stops working, death is imminent within a few hours.
In an adult person, the liver weighs about 1.5 kg. The liver is divided into two lobes – right and left. The right lobe is about three times the size of the left lobe. Pressed tightly against it is the gall-bladder.
The liver has a rich blood supply. The blood that supplies oxygen to the liver cells comes from the aorta, the main artery leaving the heart. It reaches the liver through a branch called the hepatic artery. The liver also receives blood from the intestines. This blood carries food materials that have been absorbed through the intestine wall. It reaches the liver through the hepatic portal vein. Blood leaves the liver through the hepatic vein to return to the heart. The main food materials that the liver deals with are sugar, glucose and amino acids. The amino acids come from the digestion of proteins. Sugar is stored in the liver as glycogen. It can be released to provide fuel for the body’s cells as and when necessary.
Amino acids are converted by the liver into proteins for the plasma of the blood. Some amino acids are used to make more glucose. Amino acids cannot be stored in the liver like glucose. They must be used immediately.
Liver produces a digestive enzyme called bile. It is produced inside the cells and secreted into bile ducts. It helps in digestion. Bile is stored in the gall bladder before being poured into the intestine. The liver also acts as a storehouse for vitamins, iron and copper.
A vitally important function of the liver is the destruction of harmful chemicals in the blood. Alcohol, drugs and many poisonous substances are destroyed or changed into harmless substances. They are then passed from the body through the urine. Prolonged and excessive intake of alcohol can damage the liver. This condition is known as cirrhosis of the liver. If not treated well it causes jaundice and may eventually lead to death.
The liver carries out the following functions in the body: (a) the production and storage of proteins; (b) the storage and regulation of sugar; (c) the neutralization of tonic and harmful substances; (d) the utilization and storage of fats; (e) the manufacture of bile; (f) the breakdown of drugs. It is the most vital organ of the body.
