1. Respiratory Physiology

2. Inhalation Diaphragm contracts Ribs move up and out, chest cavity enlarges and pressure decreases Air rushes in from higher pressure environment

3. Exhalation Diaphragm relaxes Ribs compress, chest cavity gets smaller and pressure increases Air escapes to lower pressure environment

4. Breathing Involuntary inhalation and exhalation Delivers O 2 to alveoli and removes CO 2 Medulla oblongata –Brain region that controls breathing

5. Control of Breathing Chemoreceptors detect change in blood pH –Blood high in CO 2 has lower than normal pH Drop in pH causes medulla oblongata to stimulate breathing

6. Normal blood pH Increase in CO 2 and blood pH Stimulation of chemoreceptors Activation of medulla oblongata Increase in breathing rate Decrease in CO 2 Restoration of normal blood pH

7. Gas Exchange

8. Watch this!