Normal System
The human digestive system, otherwise known as the gut or gastrointestinal tract, is essentially a continuous muscular tube about 7-8 metres long in adults running from the mouth to the anus (back passage). It is designed to process food and fluids which are consumed on a daily basis, the main processes involve ingestion, digestion, absorption and elimination and these are discussed in more detail in the next stage.
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Mouth
Food enters the body via the mouth where it is chewed. This action helps to break up the food enabling it to be swallowed and enter the oesophagus. The chewing action also releases enzymes which help to break down the food in preparation for the digestion process.
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Oesophagus (Gullet)
Otherwise known as the gullet or food pipe, is the first section of the digestive tract which conveys ingested food and drink from the mouth to the stomach. This is partially under the effect of gravity but also as a result of the continuous contraction and relaxation of the muscular wall of the oesophagus, a process known as peristalsis.
Stomach
Is a muscular j-shaped "bag" which acts as a receptacle for food and fluids after ingestion. Food is then churned around and mixed with gastric juices, a mixture of acid, enzymes and other materials, which starts to break down food into smaller particles in order to make digestion easier. The stomach enzymes in particular are responsible for the breakdown and digestion of proteins.
Small Intestine
This is, in fact, the longest section of the digestive tract and consists of the duodenum, the jejunum and the ileum. The small intestine is very important as it is the major site of digestion of food and subsequent absorption of essential nutrients which the body needs to function efficiently.
Large Intestine (Colon)
Otherwise known as the colon or bowel, it is the final section of the digestive tract. Indigestible food remains and fluid pass from the small intestine into the large intestine where one of the most important processes involves the absorption of water through the wall of the intestine and into the bloodstream. Therefore, as material passes through the large intestine it becomes progressively drier and more solid in consistency and the waste matter forms into faeces, or "stools".
Rectum
This is essentially a storage reservoir at the end of the large intestine and adjacent to the anus for accumulating the faeces prior to elimination from the body.
Anus
The opening at the end of the digestive tract which allows waste matter to pass through into the outside world.
