1. Objectives 30.2
Explain the process of diffusion of gases in the alveoli and capillaries
Describe the role of hemoglobin and RBC in oxygen distribution
Explain how the nervous system responds to changes in carbon dioxide levels to maintain homeostasis.

2. Warm up:
Answer the following question in your notebook:
1) During the process of respiration (breathing), where does the oxygen go once you breath it in?

3. Next:
Take note in your notebooks.

4. KEY CONCEPT The respiratory system exchanges oxygen and carbon dioxide.

5. Gas exchange occurs in the alveoli of the lungs.
Oxygen and carbon dioxide are carried by the blood to and from the alveoli.
oxygen diffuses from alveoli into capillary
oxygen binds to hemoglobin in red blood cells
carbon dioxide diffuses from capillary into alveoli
ALVEOLI
GAS EXCHANGES
alveolus
capillary
co2 o2
Co2 diffuses
into alveolus.
O2 diffuses
into blood.
capillaries

6. Gas exchange occurs in the alveoli of the lungs.
Breathing is regulated by the brain stem.
midbrain
pons
medulla oblongata
spinal chord

7. Respiratory diseases interfere with gas exchange.
Lung diseases reduce airflow and oxygen absorption.
Emphysema destroys alveoli.
Asthma constricts airways.
Cystic fibrosis produces sticky mucus.

8. Smoking is the leading cause of lung diseases.

9. Next:
We are going to do a demonstration to show the process of respiration.
I will explain the activity then pass out your supplies.

10. 1. Place the bottom of a funnel into the opening of the balloon
1. Place the bottom of a funnel into the opening of the balloon. You may need to stretch the opening of the balloon a little bit so that it fits.
2. Have a student carefully pour the yeast and the sugar into the balloon through the funnel. Then fill the measuring cup with warm water from the beaker and carefully pour the water into the balloon.
3. Remove the funnel from the opening of the balloon. Tie a knot in the balloon to keep the water-and-yeast mixture inside. Measure your balloon.

11. 4. Place the balloon in a warm place and wait 5 minutes
4. Place the balloon in a warm place and wait 5 minutes. Measure your balloon again.
5. Now sit back and wait 5 more minutes as the balloon gets bigger and bigger.
6. Record your data and answer the discussion questions when you are finished.