PATHOLOGY

Detailed explanation-1: -At each cell in your body, oxygen is exchanged for a waste gas called carbon dioxide. Your bloodstream then carries this waste gas back to the lungs where it is removed from the bloodstream and then exhaled.

Detailed explanation-2: -Carbon dioxide (CO2) is a waste product of cellular metabolism. You get rid of it when you breathe out (exhale).

Detailed explanation-3: -The lungs and respiratory system allow us to breathe. They bring oxygen into our bodies (called inspiration, or inhalation) and send carbon dioxide out (called expiration, or exhalation). This exchange of oxygen and carbon dioxide is called respiration.