1. Topic: Respiratory System Aim: How does breathing occur?
Do Now: Explain the process of gas exchange in the respiratory system.
HW: Read pages 574 – 576. Write a paragraph discussing the cause and treatment of each disorder.

2. Did you know…
Your lungs contain almost 1500 miles of airways and over 300 million alveoli.
During normal breathing, the speed that you exhale air is about 4 miles per hour.
Plants are our partners in breathing. We breathe in air, use the oxygen in it, and release carbon dioxide. Plants take in carbon dioxide and release oxygen.

4. Breathing
Inhalation  air travels into lungs
Exhalation  air pushed out of lungs
Involves the diaphragm & rib cage muscles

5. Inhalation

6. Diaphragm moves DOWN (contracts)
Rib cage expands
Air rushes in

7. Exhalation

8. Diaphragm moves UP (relaxes)
Rib cage relaxes
Air forced out

9. Maindex

12. REMEMBER…
Inhale DOWN
Exhale UP

13. What controls breathing rate?

14. Brain  MEDULLA
Detects the level of CO2 in the blood

15. 3. Which gas regulates breathing rate?
Review:
Which way does the diaphragm move during inhalation? During exhalation?
2. What happens to pressure in the chest cavity during inhalation? During exhalation?
3. Which gas regulates breathing rate?

16. 1 2 3 4 1 = TRACHEA 3 = ALVEOLI 2 = BRONCHI 4 = DIAPHRAGM
BELL JAR MODEL OF THE RESPIRATORY SYSTEM 1 2 3 4
1 = TRACHEA
3 = ALVEOLI
2 = BRONCHI
4 = DIAPHRAGM

17. BELL JAR MODEL OF THE RESPIRATORY SYSTEM
EXHALATION
INHALATION

18. EXHALATION INHALATION BELL JAR MODEL OF THE RESPIRATORY SYSTEM
Diaphragm moves UP Pressure increases Air forced up & out
Diaphragm moves DOWN Pressure decreases Air enters