Memory Anchor:

• Super Challenge:

  Stretch:

  Challenge:

Key Questions:

1. What organ is responsible for gas exchange in humans?
   • Gas exchange in humans occurs in the lungs.
2. How does the air enter the lungs?
   • Gas enters the mouth and nose and descends down the wind pipe (trachea).
3. What does the wind pipe split into when it reaches the lungs?
   • The wind pipe splits into two Bronchi. One Bronchus to each lung.
4. What are the smaller tubes the bronchi split off into called?
   • The Bronchi split into small tubes called Bronchioles.
5. What are the structures at the ends of bronchioles called?
   • The Bronchioles lead to the alveoli (air sacs)
6. What are the lungs adapted to do for gas exchange?
   • Lungs are adapted to speed up gas exchange.
7. What adaptation does the alveoli give to help gas exchange?
   • The many Alveoli give the lungs a huge internal surface area.
8. How does a large surface area help gas exchange?
   • Alveoli's large surface area allows more Particles to travel at the same time.
9. What surrounds the alveoli?
   • There is a good blood supply surrounding the alveoli.
10. Why does a good blood supply improve the rate of gas exchange?
    • Alveoli's good blood supply maintains the difference in concentration.
11. How thick are the alveoli?
    • Alveoli walls are only one Cell thick.
12. Why does the thin alveoli wall help gas exchange?
    • Alveoli's one Cell thick walls reduces the distance the Particles have to travel between the air and the blood.