Ileum - Human RNA

The ileum is part of the digestive system and is the third part of the small intestine. The first two parts of the small intestine are the duodenum and the jejunum. The ileum follows the jejunum and extends to the first part of the colon, the cecum. The ileum and jejunum constitute the major part of the small intestine and the mobile part of the small intestine

Its function is to continue the absorption of nutrients, especially water, vitamin B12, electrolytes (potassium, sodium...), and bile salts, thanks to the villi and microvilli. In the ileum, the small intestine is also protected from contamination by bacteria from the large intestine thanks to the ileo-caecal valve. This valve opens to allow chyle to pass to the cecum, the first part of the large intestine, and closes to prevent chyle from flowing back to the ileum. The ileum is characterized from the other segments of the intestine by the presence of Peyer's patches (aggregation of lymphoid tissues containing lymphocytes for immune protection) under the intestinal mucosa.