Question

A person has 400 million alveoli per lung with an average radius of 0.1mm for each alveolus. Considering the alveoli are spherical in shape, the total respiratory surface of that person is closest to

• A.
• B.
• C.
• D.

Answer 1

The correct option is C

Surface area of one alveolus = $4\times \pi \times \left(r^2\right)$
= $4\times 3.14\times 0.0001\times 0.0001m^2$
Total respiratory surface area of a man = $2\times 400\times \left({10}^6\right)\times \text{surface area of alveolus}$
= 100 $m^2)$