Eli5 – How does our respiratory system work? Specifically, how does the O2 get from our alveoli into our blood cells for transportation?

Question

Eli5 – How does our respiratory system work? Specifically, how does the O2 get from our alveoli into our blood cells for transportation?

In: 5

Answer 1

Diffusion.

Things “want” to balance out and go from high concentration to low concentrations.

There is a high concentration of CO2 in the depleted blood going into the lungs, and it is put through very small blood vessels close to the surface of the lungs. It is exposed to air with a air with a higher concentration of oxygen than the blood. So high CO2 goes to the low CO2 side, low O2 goes to the high O2 side.