1. Respiratory Physiology

2. Major Function
Supply the body with oxygen and dispose of carbon dioxide (CO2)
To do this, at least 4 distinct events must occur
Collectively called respiration

3. 1. Pulmonary Ventilation
Air must move in and out of the lungs so the alveoli are continuously changed and refreshed
Commonly called “breathing”

4. 2. External Respiration
Gas exchange (oxygen loading and CO2 unloading) between the pulmonary blood and alveoli
EXternal respiration = gas exchange between the blood and body EXterior

5. 3. Respiratory Gas Transport
Gases must be transported to and from the lungs and tissue cells of the body via the bloodstream

6. 4. Internal Respiration
Gas exchanges must be made between the lungs and tissue cells
INternal respiration = gas exchanges between blood and cells INside the body

7. Mechanics of Breathing
Breathing (aka pulmonary ventilation) depends on volume changes in the thoracic cavity
Volume changes lead to pressure changes, which lead to the flow of gases to equalize the pressure

8. Chemistry Invasion
Pressure: created by the gas molecules hitting each other and the walls of the container
It is inversely related to volume
That is, when there is high pressure, there is low volume
Gases always conform to the shape of the container and, unlike the container, fill its container
Therefore, in a large volume, the gas molecules will be farther apart and the pressure will be low
On the flip side, if the volume is reduced, the gas molecules will be closer together and the pressure will rise

10. Inspiration Inspiratory muscles Diaphragm External intercostals
The muscles in between your ribs; you eat this when you order baby back ribs