PATHOLOGY

Detailed explanation-1: -The amount of inhaled air contains 21% of oxygen and 0.04% of carbon dioxide, while the air we breathe out contains 16.4% of oxygen and 4.4% of carbon dioxide. This is because our cells use oxygen from the inhaled air to release energy and give out carbon dioxide as a byproduct.

Detailed explanation-2: -When we take a breath, we pull air into our lungs that contains mostly nitrogen and oxygen. When we exhale, we breathe out mostly carbon dioxide. Why do we do this? Our bodies need oxygen to function.