1. Respiratory System
Take a big whiff!

2. Why do we need to breathe?
All cells need oxygen
Cellular Respiration: Process of breaking down glucose into ATP

3. Primary Functions
Supply blood with O2
Remove CO2

4. Pathway of Air 1. Air enters through nose or mouth
2. Passes through pharynx

5. Pathway of Air (cont.) 3. Larynx (voice box) 4. Trachea (wind pipe)
5. Lungs

6. Pathway of Air (cont.)
CO2 & O2 exchanged in tiny sacs called alveoli

7. Pathway of Air (cont.)
Alveoli help to warm & moisten the air

8. Lung Anatomy
Trachea has 2 branches
Divided further into bronchioles

9. Lung Anatomy (cont.) Alveoli are at end of bronchioles O2 enters blood
CO2 enters alveoli

11. Inhalation 1. Lungs expand & move down
2. Diaphragm contracts & moves down

13. Exhalation
1. Lungs reduce in size
2. Diaphragm relaxes & moves up