PATHOLOGY

Detailed explanation-1: -Once in the lungs, oxygen is moved into the bloodstream and carried through your body. 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: -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).

Detailed explanation-3: -Once the venous blood returns to the lungs, the carbon dioxide diffuses out of the bloodstream, through the capillaries, and into the alveoli from where it is expelled, during which time oxygen simultaneously binds with hemoglobin to be carried back to the tissues.