1. The Respiratory System
9 Biology

2. Vocabulary Breathing Gas exchange Lungs Alveoli Capillary bed
Inhalation
Exhalation
Diffusion

3. Importance of Respiratory System
Sustains cellular respiration by supplying oxygen and removing carbon dioxide.
Two Components:
1. Breathing- mechanical movement of air into and out of the lungs
2. Gas exchange
External: exchange of gases between atmosphere and blood
Internal: exchange of gases between blood and body cells

4. Turn to your neighbor:
Discuss the difference between gas exchange and breathing.

5. Anatomy of Respiratory System

6. Structures: Nose pharynx larynx trachea
Bronchus bronchioles alveoli
Capillary beds in alveoli are where gases are exchanged.

7. Alveoli Thin walled cells surrounded by thin capillaries
O2 diffuses in, CO2 diffuses out
CO2 in blood exists as carbonic acid dissolved in plasma, bound to hemoglobin

9. Turn to your neighbor:
Explain why the O2 diffuses into the capillary beds of the alveoli and why CO2 diffuses out.

10. Mechanics of Breathing:
Inhalation- diaphragm goes down to allow filling of lungs
Exhalation- diaphragm goes up to push air out of lungs
Intercostal muscles (between ribs) assist with process

12. Respiratory Disorders
Asthma- airways swell, restricting air flow
Bronchitis- airways become infected
Emphysema- alveoli break down, reducing surface area for gas exchange
Pneumonia-infection of lungs that causes mucous to collect in alveoli
Pulmonary tuberculosis- bacterial infection that reduces capillary absorption
Lung cancer- uncontrolled cell growth in lungs that causes coughing, shortness of breath, pneumonia, infection and death.

13. Respiratory Disorders