Small intestine

After the duodenum (duodenum) small intestine continues into the section entitled jejunum(jejunum), which is long over 1.5 meters. The third part of the ileum of the small intestine (ileum)measuring about a meter.

The main function of the small intestine unlike the upper digestive tract, where digestion takes place mainly, the absorption of nutrients from the gut into the bloodstream, thus intestine and richly vascular supply. But even here there is a “dotrávení” some components of food. Consequently, it is necessary that the resorptive surface as large as possible so she intestine length and magnification resorptive area folds, villi and microvilli, which creates a form of a fine brush. This mechanism leads to increase the absorption surface intestine up to 300 m2. The intestine is lined with a single-layer columnar epithelium, in which there are many specialized cells that are adapted to the absorption of nutrients – enterocytes, goblet cells which produce the protective phlegm, Paneth cells producing antibacterial lysozyme, cells producing hormonal mediators support others. The villi are then located glands producing intestinal juice.

The movements of the small intestine – we can distinguish two types – mixing and peristaltic that pushes the chyme toward the large intestine.

Digesta passage through the small intestine takes 4-8 hours.

Diseases associated with small intestinal inflammation often have the character of their origin may be known e.g. infection or autoimmune disease – celiac disease (reaction to gluten). Another group are inflammatory bowel diseases, where there is no exact cause of development of the disease is known, here is one example. Crohn’s disease, which can affect any part of the digestive system or a high form of ulcerative colitis.Inflammation, but also a lack of digestive enzymes of the intestine can result in malabsorption syndromes, which are poorly absorbed nutrients from the gut and the body has a shortage of essential nutrients eg. Vitamins, minerals. Especially in children, this can also lead to growth failure.Less often we confronted with bowel pouches – diverticula, benign and malignant tumors.