We breathe them back out.
YES. Some GASSES will always pass through along with the oxygen into the lungs where they could cause one upper respiratory tract infection or the other. But whatever the qtty of unhealthy gas that enters the lungs, no gas passes into the bloodstreams except oxygen.
Nothing - they are "breathed out" with your exhale.
Nothing - they are "breathed out" with your exhale.
Nothing - they are "breathed out" with your exhale.
You inhale them but your lungs only absorb the oxygen- they are exhaled again when you breathe out.
When you inhale you breath in oxygen
"Inhale".
"Inhale".
To inhale
Inhale = to breathe in exhale = to breathe out
inhale oxygen
Inhale
You inhale.You inhale.You inhale.You inhale.You inhale.You inhale.