1. The Respiratory System

2. The Path of Air

3. The Path of Air Air enters through the nose or mouth
Air passes through a muscular tube called the pharynx
Air then passes through the larynx, or the voice box
Air enters the trachea, a long tube in the chest cavity

4. Path of Air
The trachea divides into smaller tubes, the bronchi, which leads to the lungs
The bronchi divide into smaller tubes called bronchioles
The bronchioles end in air sacs called alveoli
Surrounded by capillaries

5. Lungs One of the largest organs in the body
Diaphragm aids in respiration
Breathing is caused by pressure changes
What influences the breathing rate?

8. Oxygen Transport Oxygen diffuses from alveoli to the capillaries
Oxygen travels to the heart and is pumped to the rest of the body

9. Carbon Dioxide Transport
Carbon dioxide diffuses from the cells to the blood.
Bicarbonate
The heart pumps the blood to the lungs.
In the lungs, carbon dioxide is released

10. Respiratory diseases
Asthma
Emphysema
Lung cancer