Healthy Lungs - Breathing Out
The diaphragm muscle beneath the
lungs moves up and the chest
contracts to force waste air out of
the lungs.
Waste air from the body (carbon
dioxide – CO2) is carried by the
blood vessels back to the air sacs
to be exhaled through the airways,
windpipe, and nose.
CO2 passes from the blood vessels
into the air sacs.
