Question

How is oxygen circulated to the body?

Answer 1

Circulation of oxygen:

1. Oxygen is respired into the body via the nasal cavity into the lungs.
2. The oxygen enters the body at the thin epithelium lining of the alveolar (sac-like structure which helps in exchanging gases) surface of the lungs.
3. It enters the capillaries of the lungs.
4. From capillaries blood enters the blood vessels to circulate it to every tissue of the body.
5. Oxygen is exchanged with CO₂ at every tissue surface hence filling the capillaries with deoxygenated blood.