Question

A unique feature common to both the alveoli of lungs and the villi of the intestine, is that both

• A. Have ciliated columnar epithelium
• B. Are suited for diffusion of gases
• C. Provide a large surface area
• D. Have a rich supply of blood vessels and lymph ducts.

Answer 1

The correct option is C

Provide a large surface area

The alveoli are tiny, circular air sacs which are important because they significantly increase the surface area of the lungs. Due to the many walled surfaces of the alveoli, the lungs of a single person have a surface area that is approximately the size of a tennis court. The villi of the small intestine are similar to the alveoli in that they tremendously increase the surface area. However, the alveoli perform the function of gas exchange, while the villi of the small intestine are involved in the absorption of nutrients from digested food.