1. Respiratory system Primary function: supply the blood with oxygen so it can deliver O 2 to all parts of the body.

2. A.What Is Respiration? Process by which body obtains & uses O 2 (oxygen) and eliminates CO 2. (carbon dioxide) (in other words, breathing)

3. Inhalation Exhalation Air in Air out Diaphragm Ribs rise Ribs fall Mechanisms of Breathing

4. Human Respiratory System

5. Structures (pg. 957) nose mouth pharynx larynx epiglottis trachea lung bronchi alveoli diaphragm

6. STEPS OF RESPIRATION (BREATHING) Step 1. O 2 - rich air enters the nose and is warmed, moistened & filtered

7. Step 2. Air enters the pharynx (where nose & mouth come together)

8. Step 3. Air then passes through the trachea, “aka the windpipe” (main passage to the lungs). Made of rings of cartilage. trachea

9. Step 4. The trachea divides into 2 branches: BRONCHI (respiratory tubes that lead to the lungs) Bronchi branch into smaller tubes called bronchioles bronchi bronchioles

10. Step 5. Bronchioles end in tiny sacs called ALVEOLI (look like a bunch of grapes). * Most gas exchange between circulatory and respiratory systems takes place in the alveoli.

11. O 2 more concentrated in alveoli - able to diffuse into blood in capillaries. CO 2 more concentrated in capillaries - able to diffuse into alveoli where it is exhaled.

12. Important Molecules Soap-like molecules that coat inner surfaces of alveoli & keep membranes open. Surfactants

13. HEMOGLOBIN Is a Protein located on the surface of RBC (gives color) Most of the o 2 needed by the body is bound to this protein.

14. Respiratory Illness/disorders 1. COLDS: brought on by virus, attacks nasal mucous membrane 2. PNEUMONIA: inflammation of alveoli, fluids accumulate & debris interferes w/gas exchange. 3. BRONCHITIS: inflammation of bronchial tube membranes (brought on by bacteria, colds)

15. 4. ASTHMA - narrowing of bronchial tubes and swelling of the mucous membranes. (allergy-related)

16. 5. Alveoli loose their elasticity (stay filled w/air after exhaling)

17. Diseases caused by smoking:

18. The 411 on Tobacco 1. Ingredients - cyanide - carbon monoxide - nicotine (addictive drug that stimulates nervous system)

19. In regular respiration, O 2 hooks onto hemoglobin in the blood & is transported to the body. When smoke is inhaled, O 2 is replaced by CO (which is toxic).