Size of villi ranges between 0.5 to 1.6 mm while that of microvilli is about 1 µm in length. Additionally, villi are seen on the mucous membrane, specifically in the small intestine. Microvilli, on the other hand are small extension seen on the cell membrane of various structures.

Villi are the numerous finger like projections, whose walls are richly supplied with blood capillaries and lymph vessels. They are able to contract and relax continuously, thus bringing themselves into close contact with the food in the small intestine.

These villi and microvilli together increase the surface area of the mucous membrane. Moreover, each villus also has a central channel known as the lacteal that opens into the lymphatic vessels. It also contains blood vessels. These intestinal villi are numerous and large in jejunum and duodenum but fewer and smaller in the ileum. Intestinal Gland

The main function of small intestine is absorption. Absorption is directly dependent on surface area. So to increase the surface area, the internal surface of the intestinal wall is folded onto itself creating villi.

The villi are known to provide more surface area within the small intestine for better absorption of the broken down digested food into the blood. Absorption: In this process, the digested food within the small intestine is now transported to the blood via …

Villi: Any of the tiny, thin vascular projections that enhance the surface area of a membrane are known as villus, plural villi, in anatomy. The placenta and the mucous membrane lining the small intestine are significant villous membranes. The small intestine's architecture is optimized for nutrient absorption.

The finger-like projections known as villi, drastically increase the surface area of the small intestine for greater absorption of the digested food. The blood carries the absorbed food material to different parts of the body. Glucose breaks down to form oxygen and carbon dioxide and releases the energy required for various life processes.

Both the alveoli in the lungs and villi in the small intestine are in direct contact with blood capillaries. this enables gaseous exchange in the lungs via alveoli, and absorption of nutrients in the small intestine via villi. Also, both increase the surface area of absorption.

The alimentary canal is the pathway by which the food we eat passes from mouth to anus for further process of digestion. Explore more about alimentary canal at BYJU’S

The correct option is A. A. Capillaries, B. Lacteal and C. Artery. The small intestine contains small finger-like projections called villi which increase the surface area of the intestine and contain specialized cells that transport substances into the bloodstream.