“Life depends on the liver”
The liver is integral to the digestive system, producing both internal and external secretions. The external secretion, bile, aids in the digestive process, while internal secretions are responsible for the metabolism of both nitrogenous and carbohydrate materials absorbed from the intestine.
As the largest gland in the human body, the liver serves several important functions. It secretes bile in order to chemically alter toxic substance (e.g. converts ammonia to urea), converts glucose to glycogen, and can produce glucose from breaking down certain proteins. The liver also synthesizes triglycerides and cholesterol, breaks down fatty acids and produces plasma proteins necessary for the clotting of blood such as clotting factors I, III, V, VII, IX and XI. Nearly 30% of the blood pumped by the heart passes through the liver in one minute.
One of the unique structural features of the liver is its dual blood supply. It is supplied both by an artery (hepatic artery) and a vein (yes a vein!) – the portal vein. The portal vein (shown in the diagram below) drains the gastrointestinal tract of digested metabolic products and transports the nutrients to the liver for processing.
4000 – 5000 years ago, the sheep’s liver held godly powers over the Babylonian culture. The Babylonians, and many cultures thereafter, believed that since the liver was the largest organ, it certainly must be the organ of most importance.