Question

Mammalian lungs have an enormous number of minute alveoli (air sac);This is to allow

• A. more surface area for diffusion of gases
• B. more space for increasing the volume of inspired air
• C. more nerve supply to keep the lungs working
• D. more spongy texture for keeping lung in proper shape.

Answer 1

The correct option is A more surface area for diffusion of gases

The number of alveoli in the human lungs has been estimated to be approximately 300 million. This enormous number of alveoli are meant to increase surface area of lungs for diffusion of gases.