Oxygen Delivery: How Your Body Gets Oxygen from Air to Cells

The body gets its oxygen from the air we breathe. When we inhale, air enters our lungs and travels through the airways to the tiny air sacs called alveoli. The alveoli are surrounded by capillaries, which are tiny blood vessels. Oxygen from the alveoli diffuses across the capillaries into the red blood cells. The red blood cells then carry the oxygen throughout the body.