1. Mechanics of Breathing November 28, 2015

2. Mechanics of Breathing November 28, 2015

3. Mechanics of Breathing November 28, 2015 human rib cage human rib cage (breathing)

4. Mechanics of Breathing thoracic cavity: formed by: a) rib cage & intercostal muscles b) diaphragm lined by pleural membranes November 28, 2015 diaphragm intercostal muscles bands of muscles between ribs thoracic cavity trachea

5. Inhalation inhalation- involves: 1.intercostal muscles contract pull rib cage up & out 2.diaphragm contracts (pulls down) causing it to flatten out November 28, 2015 diaphragm pulls down intercostals pull up & out

6. Inhalation Causes: volume of chest cavity to ___________ therefore air pressure in chest __________ making it __________ than atmospheric pressure therefore air _____________ to equalize air pressure November 28, 2015 lower rushes in decreases increase

7. November 28, 2015 7 Inhalation

8. Exhalation November 28, 2015 exhalation- involves: 1.intercostal muscles relax rib cage returns to normal 2.diaphragm relaxes returns to normal intercostals go back down & in diaphragm goes back up

9. Exhalation Causes: volume of chest cavity to ___________ therefore air pressure in chest __________ making it __________ than atmospheric pressure therefore air _____________ to equalize air pressure November 28, 2015 higher rushes out increases decrease

10. November 28, 2015 10 Exhalation

11. Breathing Rate Lab Do Breathing Rate Lab and hand in by the end of class.

12. Mechanics of Breathing November 28, 2015 External intercostal muscles involved in normal breathing Internal intercostal muscles involved when forcefully exhaling ex. blowing out a candle