Question
Biology Question on Exchange Of Gases
In man total number of alveoli in both lungs are
A
3000
B
30000
C
500000000
D
none of the options is correct
Answer
none of the options is correct
Explanation
Solution
None of the options is correct. The alveoli (made of simple squamous epithelial cells) are the final branching of the respiratory tree and act as the primary site for gas exchange. There are about 300 million in the two lungs and each alveolus has an average diameter of about 0.2 millimeter.