Question

blood that flows to the lungs contains more carbon dioxide than oxygen is called what?

Answer 1

Deoxygenated blood.
The blood is deficient in oxygen but rich in carbon dioxide.
The deoxygenated blood goes to lungs

Answer 2

It's called deoxygenated blood. Once it reaches the lungs, oxygen diffuses into it and carbon dioxide diffuses out of it and it becomes oxygenated blood.