1. The Path of Air Gas Exchange
The Lungs- main organs of the respiratory system.
Alveoli- grape-like structures Where gas exchange happens.
Increase surface area in lungs.
Gas Exchange
After air enters alveolus, oxygen passes through the wall of the alveolus and then through the capillary wall into the blood.
Carbon dioxide and water pass from the blood into the alveoli, then leave the body.

2. - The Respiratory System
Gas Exchange

3. How You Breathe In an average day, you may breathe over 20,000 times.
Breathing is controlled by muscles.
Diaphragm- dome-shaped muscle that helps you breathe.
Muscles of rib cage also help you breathe.

4. - The Respiratory System
How You Breathe

5. Breathing and Speaking
Larynx- voice box
Vocal Cords- vibrate to make sounds.

6. Chemicals in Tobacco Smoke
Tar- dark, sticky substance (forms when tobacco burns).
- Sticks to cilia and causes them not to function, also causes cancer
Carbon Monoxide- released when tobacco burns.
- Clings to hemoglobin and reduces oxygen delivered to cells
- Smokers have higher respiration rates to get oxygen required by body

7. Chemicals in Tobacco Smoke
Nicotine- found in tobacco
- stimulant that speeds up nervous system and heart rate
Smokers get addicted to nicotine

8. Health Problems & Smoking
Smokers are at high risk of chronic bronchitis, emphysema, lung cancer, and atherosclerosis
Bronchitis- inflammation of bronchioles, makes breathing difficult
Emphysema- destroys lung tissue and makes breathing difficult, not enough oxygen delivered to cells, sufferers are short of breath

9. Health Problems & Smoking
Lung Cancer- kills about 140,000 smokers a year
- tumors take up surface area in lungs, makes breathing harder and less efficient
Atherosclerosis- chemicals from lungs enter circulatory system and destroy blood vessels
- smokers are 2 times more likely to have heart attacks than non smokers

10. Health Problems & Smoking
- Smoking and Your Health
Health Problems & Smoking