Eli5: why are we told to breathe in through your nose and out through your mouth if all the oxygen gets in your blood stream in the lungs either way? Would it not be better to just breathe in and out of your mouth for the most oxygen?

Question

Eli5: why are we told to breathe in through your nose and out through your mouth if all the oxygen gets in your blood stream in the lungs either way? Would it not be better to just breathe in and out of your mouth for the most oxygen?

In: Biology

Answer 1

Breathing in through your nose is very important. “Nitric oxide is produced in the paranasal sinuses and is excreted continuously into the nasal airways of humans” I am no scientist but I read NO helps to modulate your breathing and absorb oxygen.