How much $CO_2$ is delivered to the alveoli by every $100 \;ml$ of deoxygenated blood (in $;ml$)?

Which are the three main layers that form the diffusion membrane?

Explain: Diffusion of $O_2$ from alveoli to tissues and of $CO_2$ from tissues to alveoli.

People living at sea level have around $5$ million $RBC$ per cubic millimeter of their blood,whereas those living at an altitude of $5400$ metres have around $8$ million. This is because at high altitude:

Partial pressure of a gas is the pressure contributed by

Maximum amount of oxygen is exchanged from the blood in the . . . . . . .