The Liver The liver is the second largest organ in the human body, after the skin. Its role is to process and distribute the nutrients from food and decompose unwanted or potentially dangerous molecules. The liver breaks down damaged red blood cells and uses their pigments, along with mineral salts, fatty acids and water to make bile. Bile is a bitter fluid released into the duodenum to digest chyme. When the bile is not needed it is stored in the gall bladder. Approximately one litre (2.1 pints) of bile is produced a day. The bile breaks down the fats in chyme, the bile salts turns fat into tiny particles which allows the other digestive juices to act on the molecules. It makes the fatty acids soluble so they can be absorbed by the villi in the duodenum. The other main roles of bile are to kill germs in the upper intestinal tract and hold other substances in solution so they can be absorbed. The pigments of the red blood cells give bile its amber colouring, which is passed onto the urine and faeces, giving them their distinctive colour. The liver also decomposes molecules which can't be used by the body and passes them onto the kidney so they can be removed from the body though urine. It converts sugars into glucose and stores vitamins A and D, releasing them when they are needed around the body.

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