Oxygen enters via the lungs.
Oxygen enters the blood in the alveoli of the lungs
Oxygen enters the blood in the alveoli of the lungs
Oxygen enters via the lungs.
The air that enters the lungs is richer in oxygen when it enters the lungs. when it leaves it has more carbon dioxide and less oxygen as the lungs expel carbon dioxde and some unused oxygen.
the lungs
Oxygen
blood
Oxygen
Oxygen rich air enters the body through the lungs.
Inhalation/Inspiration
Oxygen in the lungs and passes through the alveoli, small sacs which allow gas exchange, and enters the blood to be pumped throughout the body.