MagenDarmTrakt

The Magen-Darm-Trakt, often written as Magen-Darm-Trakt in German, and known in English as the gastrointestinal tract (GI tract), is a continuous tube from the mouth to the anus. It processes ingested food, extracts nutrients, and eliminates indigestible material. The tract works in concert with accessory organs such as the liver, gallbladder, and pancreas to facilitate digestion.

Anatomy: The tract includes the upper digestive tract (mouth, esophagus, stomach) and the lower digestive tract (small intestine: duodenum, jejunum, ileum; large intestine: cecum, colon, rectum). The anus provides defecation. The liver produces bile, the gallbladder stores it, and the pancreas delivers digestive enzymes and bicarbonate into the duodenum. Blood supply and nerves run through mesenteries to support the organs.

Function: Mechanical processing and chemical digestion occur via saliva, gastric acid, enzymes, and bile. The small intestine is the main site of nutrient absorption, followed by water absorption and feces formation in the large intestine. The gut also houses a complex microbiota that interacts with the immune system and influences metabolism and barrier function.

Regulation and development: Motility is coordinated by the enteric nervous system and autonomic input, with hormonal signaling regulating secretion and appetite. Developmentally, the tract forms from foregut, midgut, and hindgut regions that differentiate into the organs described.

Health and disease: The GI tract is subject to disorders such as gastroesophageal reflux disease, peptic ulcers, inflammatory bowel disease, irritable bowel syndrome, celiac disease, infections, and colorectal cancer. Diagnosis commonly uses endoscopy and imaging, while treatment ranges from dietary changes and medications to surgical intervention when necessary.