Gas exchange in the lungs

Question 1

How are alveoli adapted to gas exchange?

Answer 1

They are only one cell thick to reduce the diffusion pathway for gases
There are millions of them which means there is a large surface area and diffusion can happen quicker
They have a very good blood supply to ensure the concentration gradient is as steep as possible so diffusion can happen faster

Question 2

How does breathing effect gas exchange in the lungs?

Answer 2

When we breathe, we increase the rate of diffusion as we increase the amount of oxygen and reduce the amount of CO2