Tarmen

Tarmen, or the intestines, are the portion of the digestive tract between the stomach and the anus. They consist of the small intestine and the large intestine and are responsible for digestion, nutrient absorption, water reabsorption, and feces formation.

The small intestine measures about 6 meters in adults and comprises three segments: the duodenum, where chyme mixes with bile and pancreatic juices; the jejunum, where most nutrient absorption occurs; and the ileum, where bile acids and vitamin B12 are reabsorbed. The lining is folded into villi and microvilli to increase surface area.

The large intestine encircles the small intestine and includes the cecum, colon (ascending, transverse, descending, sigmoid), and rectum. Its main tasks are absorbing water and electrolytes, forming and storing feces, and hosting a diverse gut microbiota that ferment indigestible carbohydrates into short-chain fatty acids.

The intestinal wall has a layered structure—mucosa, submucosa, muscularis, and serosa—and is supplied by mesenteric blood vessels. Motor activity, coordinated by the enteric nervous system, drives peristalsis and segmentation. The gut-associated lymphoid tissue provides immune defense, and the microbiome contributes to digestion, vitamin production, and immune modulation.

Common health issues affecting the tarmen include inflammatory bowel disease (Crohn’s disease and ulcerative colitis), diverticular disease, colorectal cancer, colorectal polyps, and bowel obstruction. Nutritional status can be affected by malabsorption syndromes and chronic inflammatory conditions.