1. Section 12.3 Respiratory Health Objectives
List the functions of the respiratory system.
Describe how air travels through your respiratory system, and how you breathe.
Identify ways to keep the respiratory system healthy.

2. Health Stats What does the graph suggest about asthma rates?
Describe some factors that could contribute to the rise and fall of asthma rates.

3. The Respiratory System
• The respiratory system is responsible for bringing oxygen from the outside environment into the body.
It also removes carbon dioxide from the body.

4. The Pathway of Air On its way to the lungs, air passes through the
nose
pharynx
larynx
trachea
bronchi

5. The Respiratory System
Cilia
Cilia line most of the respiratory tract. Cilia capture mucus that contains dust and microorganisms and sweep it toward your throat to be swallowed.
The Respiratory System
Nose and Nasal Cavities Air enters the body through two nostrils and then moves into the nasal cavities.
Trachea The trachea, or windpipe, leads from the larynx to the lungs.
Bronchus The trachea divides into two bronchi (singular, bronchus), which are cartilage-ringed tubes that enter each lung.
Pharynx Next air enters the pharynx, or throat. The mouth also connects to the pharynx.
Epiglottis and Larynx Air travels from the pharynx to the larynx. The larynx contains the vocal cords. When you swallow, the epiglottis seals the larynx to prevent food or liquid from entering the trachea.
Lung In the lungs, bronchi divide like branches of a tree into smaller tubes. At the end of the smallest tubes are the alveoli. Oxygen and carbon dioxide are exchanged in alveoli.

6. Gas Exchange
At the end of the smallest tubes in the lungs are millions of tiny sacs that look like bunches of grapes.
These sacs, called alveoli (singular, alveolus), are where gases are exchanged between the air and the blood.

7. Alveoli
Blood rich in carbon dioxide
Capillary
Blood rich in oxygen

8. The Breathing Process
The breathing process is controlled by the actions of muscles in your ribs and chest.
Inhalation
When you inhale, the diaphragm (DY uh fram), a dome-shaped muscle that lies below the lungs, flattens.
The chest cavity enlarges, the volume of the lungs increases, and air flows in.
Exhalation
When you exhale, or breathe out, the diaphragm moves upward.
The rib muscles relax and the ribs drop.
These movements make the chest cavity smaller and squeeze air from the lungs.

9. Exhalation The volume of the lungs decreases, and air is pushed out.
Inhalation The volume of the lungs increases, and air flows in.

10. Active Art: The Respiratory System
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11. Keeping Healthy You can keep your respiratory system healthy by
avoiding tobacco smoke and air pollution
treating asthma if you have it
avoid respiratory infections
get regular exercise
maintain a healthy weight

12. Avoiding Smoking and Air Pollution
The most important think you can do to protect your respiratory system is not to smoke.
It is also important to avoid exposure to air pollutants whenever possible.
If you do work that generates fumes or dust wear a mask.
Work in a well-ventilated area when you paint or use other chemicals.
Before exercising outdoors on a hot, sunny day, check local news reports for warnings about air quality.

13. Living With Asthma
Asthma (AZ muh) is a disorder in which respiratory passageways become inflamed.
During an asthma attack, the passageways narrow until air can barely pass through.
As a result, the person wheezes, coughs, and has difficulty breathing.

15. For: Updates on asthma
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16. Other Healthful Behaviors
Avoid Respiratory Infections Bronchitis is an infection that causes the mucous membranes lining the bronchi to become inflamed.
Get Regular Exercise Exercise helps your lungs become more efficient at taking in oxygen and eliminating carbon dioxide.
Maintain a Healthy Weight The respiratory system of an overweight person must work harder to deliver adequate oxygen than the system of a normal weight person.

17. Vocabulary
alveoli
The sacs in the lungs where gases are exchanged between the air and the blood.
diaphragm
A dome-shaped muscle below the lungs that is involved in the breathing process.
asthma
A disorder in which respiratory passageways become inflamed and narrow during attacks, leading to difficulty breathing.
bronchitis
An infection that causes the mucous membranes lining the bronchi to become inflamed.

18. QuickTake Quiz
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19. For: Chapter 12 self test
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20. End of Section 12.3 Click on this slide to end this presentation.