Question

Wy should we breathe only through the nose but not through the mouth?

Answer 1

Because the nostrils are smaller than the mouth, air exhaled through thenose creates a back flow of air (and oxygen) into the lungs. And becausewe exhale more slowly through thenose than we do though the mouth, the lungs have more time to extract oxygen from the air we've already taken in.

Answer 2

Because the nostrils are smaller than the mouth, air exhaled through the nose creates a back flow of air (andoxygen) into the lungs. And becausewe exhale more slowly through the nose than we do though the mouth, the lungs have more time to extract oxygen from the air we've already taken in.