How food is digested
How food is digested
The nutrients your body needs for energy, maintenance and repair – including amino acids, glucose, fatty acids, vitamins and minerals – must first be extracted from food by the process of digestion.
Digestion begins in your mouth as you chew the food you are eating to break it up into smaller pieces. Chewing also stimulates the production of saliva, which contains enzymes that begin to break the food down chemically. Food combined with saliva passes through a long tube (pharynx and oesophagus) that stretches down your throat and chest and into the stomach. From there, the food goes through the small intestine (duodenum, jejunum and ileum) and the large intestine (caecum, colon and rectum). The tube ends at the anus.
As food travels, several organs – stomach, liver, pancreas and the intestine, in addition to the salivary glands – add digestive juices and other substances to it that help to break the food down into simpler substances. Once
the foods are broken down, or digested, the smallest units (nutrients and many non-nutrients) are absorbed through the linings of the digestive organs into the bloodstream and the lymphatic system, which distribute them throughout the body. Waste materials remaining after digestion are expelled from the body as urine or faeces.
