The Lungs

• When breathing in, air starts by moving into the body through the mouth and nose.
• Air moves down the trachea after entering the body.
• Air moves from the trachea into the bronchi and through the bronchioles.
• Air moves from the bronchioles to the alveoli.
• Oxygen diffuses from the alveoli into the blood in the network of capillaries surrounding the alveoli.