1. RESPIRATORY SYSTEM:
EXCHANGE OF GASES

2. What is its role? Provides O2 needed by the body
Removes CO2 produced by body
Works closely with the circulatory system

3. The Four Processes of the Respiratory System:
Breathing: air in to and out of lungs
External respiration: gas exchange between air and blood (occurs in lungs)
Internal respiration: gas exchange between blood and tissues (occurs in body capillaries)
Cellular respiration: oxygen used to produce ATP, carbon dioxide is waste (occurs in cells)

4. Human Respiratory System
Figure 10.1

5. Components of the Upper Respiratory Tract
Figure 10.2

6. What does the Upper Respiratory tract do?
Passageway for respiration
Receptors for smell
Filters incoming air to filter larger foreign material
Moistens and warms incoming air
Resonating chambers for voice

7. Components of the Lower Respiratory Tract
Figure 10.3

8. What does the Lower Respiratory Tract do?
Larynx: maintains an open airway, routes food and air appropriately, assists in sound production
Trachea: transports air to and from lungs
Bronchi: branch that leads into lungs
Lungs: transport air to alveoli for gas exchange
Alveoli : site where gas exchange occurs with the capillaries

9. Gas Exchange Between the Blood and Alveoli
Figure 10.8A

10. How do we breathe?
Figure 10.9

11. Disorders of Respiratory System
Reduced air flow:
Asthma – inflammation of airwaves
Emphysema – destruction of tissues around alveoli
Infections:
Bronchitis – bacterial infection of bronchi and bronchioles
Pneumonia – many causes, alveoli fill with fluid
Tuberculosis – M. tuberculosis infection of alveoli
SARS – Viral infection of lungs, near pandemic in 2003
Cancer – smoking is a major cause of lung, mouth, esophagus, larynx, pancreatic, and bladder cancer
Pneumonia can result from a variety of causes, including infection with bacteria, viruses, fungi, or parasites, and chemical or physical injury to the lungs. Its cause may also be officially described as unknown when infectious causes have been excluded.

12. Respiration in Fish Gills exchange gases that are dissolved in water
Gills are lined with capillaries, just like lungs
Fish may open and close their mouths to ensure water flow
Other fish need to move constantly