Hint:Small intestine is vested with the function of absorption. This function depends solely on the surface area of the intestinal wall. Villi provides a lot of area of absorption by forming a brush border epithelium.
The walls of the small intestine are highly absorptive in nature. Intestinal villi are tiny, finger-like projections made up of cells that line the entire length of the small intestine. The villi (villus is singular and villi are plural) absorb nutrients from the food we eat and then shuttle those nutrients into the bloodstream so that they can be sent where they are needed.
If one doesn’t have functioning intestinal villi, they can become malnourished or even starve, regardless of how much food they eat, because the body simply isn't able to absorb and make use of that food.
Additional information: There are several different medical conditions that may cause damage to the intestinal villi.
In celiac disease, consumption of the protein gluten (found in the grains wheat, barley, and rye) triggers the immune system to attack the intestinal villi and wear them down. This process is known as villous atrophy. Many people with celiac disease have vitamin and mineral deficiencies when they are first diagnosed because their intestinal villi have been damaged.
Inflammatory bowel disease, which also includes Crohn's disease, can cause the intestinal villi to erode.
Lymphoma and certain other infections, like an infection involving the parasite Giardia, can also lead to wearing out of the intestinal villi.
Some medications can also cause damage to the intestinal villi. These include Benicar (generic name – olmesartan), a blood pressure medicine, and some over – the – counter pain medications, such as aspirin and ibuprofen. Fortunately, in these cases, discontinuing the medication may result in the villi growing back.
Note: Villi are a very important feature in the procedure of digestion and absorption of food. Brush border epithelium can increase the surface area by almost 10 times. Hence, absorption of food becomes hastened.