Technische Universität München

The Entrepreneurial University

The intestinal tract is a muscular digestive tube lined by a mucosa membrane that winds through the human body starting by the mouth ending of the anus. Its function is the digestive process characterized by ingestion, propulsion, mechanical digestion, absorption, chemical digestion, and defecation of non-digestive parts.

The first part is the upper intestinal tract built by the mouth, pharynx, esophagus and the stomach. After ingestion, the food will be hackled by the teeth and prepared for further transport to the stomach by saliva and muscle contractions. The food is further digested chemically into its molecules: carbohydrates, proteins and lipids by hydrochloric acid and biochemically by enzymes. In the musculature of the stomach a wavelike contraction movement will be initiated to transport the food to the bowel.

The second part is built by the bowel consisting of the small intestine (duodenum, jejunum and the ileum) and the large intestine (colon). The nutrients (as well as drugs) are now prepared to be resorbed by the different parts of the bowel`s mucosa and get into the bloodstream or the lymph channels. The pancreas and the gall bladder discharge further digestive enzymes and neuroactive substances into the duodenum. The non absorbable parts and the dietary fibres remain in the bowel.