How does the villi aid absorption by the small intestine?
The small intestine is the primary organ of the digestive tract. It is subdivided into 3 segments: 1) Duodenum 2) Jejunum 3) Ileum Most of the food digestion through acids and bases occurs in the small intestine. The small intestine has three structures to handle absorption 1) Villi 2) Microvilli 3) Circular folds The purpose of these is to increase the area of absorption. The structure of the villi is very similar to the microvilli except that villi are substantially larger than the microvilli. ** Within all villi are a large number of capillaries and lymphatic capillary as well. ** Villi are structures, which act as valves, which allows solid foods and/or acids to pass through one structure to another. Thus, all useful nutrients that are located in chyme, pass through the small intestine into the bloodstream. Valves have a unilateral flow.
