RESPIRATORY SYSTEM:RESPIRATORY SYSTEM:

EXCHANGE OF GASESEXCHANGE OF GASES

•Provides O2 neededneeded by the body

•Removes CO2 producedproduced by body

• Works closely with the circulatory system

What is its role?

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)

The Four Processes of the Respiratory System:

Human Respiratory System

Figure 10.1

Components of the Upper Respiratory Tract

Figure 10.2

Passageway for respiration Receptors for smell Filters incoming air to filter larger

foreign material Moistens and warms incoming air Resonating chambers for voice

What does the Upper Respiratory tract do?

Components of the Lower Respiratory Tract

Figure 10.3

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

What does the Lower Respiratory Tract do?

Gas Exchange Between the Blood and Alveoli

Figure 10.8A

How do we breathe?

Figure 10.9

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

Disorders of Respiratory System

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