Question

The given picture depicts the surface of the small intestine. What is the main reason for it to be so convoluted?

• A. It is to increase the surface area for absorption
• B. It is to increase the grinding of food
• C. It is to slow down the movement of food
• D. It is to store food for emergency

Answer 1

The correct option is A

It is to increase the surface area for absorption

The main function of the 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. Again the surface of each villus is convoluted in a similar fashion and the resulting microscopic structures are called as microvilli (brush border). Such a convoluted surface increases the area for absorption.