Question

How many alveoli are there in the average male lung?

Answer 1

Alveoli are the source of the gas exchange for the respiratory tract. The alveoli absorb the energy generated (oxygen) you breathe in and emit the carbon dioxide (outgoing waste product) you expel.
Your blood absorbs the oxygen from alveoli and releases carbon dioxide to the alveoli as it passes into blood vessels in the walls of the alveoli.

Complete answer:
In the lungs, alveoli are small air sacs that soak up the oxygen you inhale to keep the body moving.
Though they are microscopic, the workhorses of the respiratory system are the alveoli.
For the direct and unbiased calculation of the alveolar number in the human lung, a design-based stereological technique was used.
The definition is centred in three-dimensional space on two-dimensional topology and is free of assumptions about the form, scale, or spatial orientation of alveoli.
The male lung is roughly $3L$, while the female average is $2L$. Usually; the amount of adult female lungs is $10 - 12$ percent less than that of males of the same age and height.
A critical structural determinant of lung architecture seems to be the number of alveoli.
By counting their gaps at the level of the free sepal margins, where they create a two-dimensional web, the alveolar number is determined.
Mathematically, utilizing physical dissectors at such a light microscopic level, the Euler number of such a network is determined.
The mean alveolar value in six adult human lungs became $480$ million.

Note: The alveoli are clustered into bunches, grouping each bunch into what is called the alveolar sac. As grapes in a close cluster, the alveoli meet each other.
What brings a spongy quality to the lungs is the amount of alveoli and alveolar sacs. Each of the alveoli has a diameter of around $0.2$ millimetres.