2. Breathing  The primary function of breathing is to supply the blood with oxygen  Oxygen is needed by every cell in the body to release the energy from glucose in a process called respiration.

3. Anatomy of Breathing  Oxygen enters the respiratory system through the mouth and the nose.  The oxygen then passes through the larynx (voicebox) and the trachea; which is a tube that enters the chest cavity.  In the chest cavity, the trachea splits into two smaller tubes called the bronchi (singular = bronchus).

4. Anatomy of Breathing  Each bronchus then divides again forming smaller tubes called bronchioles.  The bronchioles lead directly into the lungs where they lead to tiny sacs called alveoli.

6. Anatomy of Breathing  The inhaled oxygen passes into the alveoli and then diffuses through the capillaries into the blood.  Carbon dioxide from the veins is released into the alveoli and follows the same path out of the lungs when you exhale.

7. Anatomy of Breathing Inhaled Air Oxygen (21%) Carbon Dioxide (0.4%) Exhaled Air Oxygen (17%) Carbon Dioxide (4%)

8. Alveoli  Are important to increase the surface area of the lungs.  The average adult's lungs contain about 600 million of these spongy, air-filled sacs

9.  Copy the alveoli structure diagram on Pg. 20

10. Asthma

11. Emphysema  Caused by exposure to toxic chemicals or long-term exposure to tobacco smoke.

12. Emphysema

13. Asthma  When the airway becomes inflamed and is lined with excessive amounts of mucus.  These episodes may be triggered by such things as exposure to an environmental stimulant (or allergen), cold air, warm air, moist air, exercise or exertion.

14. Asthma