ANATOMY

Detailed explanation-1: -Carbon dioxide is made in our bodies as cells do their jobs. The lungs and respiratory system allow oxygen in the air to be taken into the body, while also letting the body get rid of carbon dioxide in the air breathed out.

Detailed explanation-2: -When we breathe, the respiratory system takes in oxygen and sends out carbon dioxide. The cells in our bodies need fresh oxygen to stay alive. As cells do their jobs, they make and give off carbon dioxide. This exchange of oxygen and carbon dioxide is called respiration.

Detailed explanation-3: -The average human exhales about 2.3 pounds of carbon dioxide on an average day. (The exact quantity depends on your activity level-a person engaged in vigorous exercise produces up to eight times as much CO2 as his sedentary brethren.)