Question

why are alveoli so small and uncountable in nature?

Answer 1

Alveoli are smaller in size as they are necessary for gaseous exchange in large numbers.The gaseous can be exchanged with small area of cross section which are capable of holding it.

Answer 2

alveoli are so small and uncountable in nature ...alveoli is meant for purification process of air ...which is really essential for life process...lungs and alveoli has residual air so that it maintains the time between the exchange of gases...