The ileum is a part of the small intestine, located between the jejunum and the cecum. It is the final section of the small intestine, extending from the jejunum at the duodenojejunal flexure to the ileocecal valve, where it enters the large intestine.
The primary function of the ileum is to absorb nutrients from the digested food and facilitate their transportation into the bloodstream. It accomplishes this by using millions of tiny, finger-like projections known as villi and microvilli. These structures significantly increase the surface area of the ileum, allowing for enhanced absorption of nutrients like vitamins, minerals, and electrolytes, as well as the breakdown products of carbohydrates, proteins, and fats.
Additionally, the ileum plays a crucial role in the immune system. It contains numerous lymphoid follicles, which are involved in the production of antibodies and the recognition of foreign substances. These lymphoid follicles are part of the gut-associated lymphoid tissue, collectively known as Peyer's patches.
The ileum also has a unique ability to perform segmentation movements, which help to mix and propel the intestinal contents further towards the large intestine. This function aids in the overall digestive process.
In summary, the ileum is the terminal portion of the small intestine responsible for nutrient absorption, immune function, and propulsion of the intestinal contents towards the large intestine. Its complex structure and functions make it a critical component of the digestive and immune systems.
