1. Bio 449 Lecture 21 – Respiratory Physiology II Oct. 27, 2010
Mechanics of ventilation Pressure and pumps Thoracic cavity Intrapleural pressure Inspiration and expiration Alveolar gas composition Atmospheric gases Partial pressures Effects of ventilation pattern Anatomical dead space Alveolar gases
Terms to Know Thoracic cavity Diaphragm Pleural membrane Intrapleural fluid Compliance Inhalation Exhalation External intercostals Internal intercostals Partial pressure Tidal volume Anatomical dead space Minute ventilation Alveolar ventilation
Readings
Lectures 21-22: Chapter 17
Lectures 23-24: Chapter 16, pages Chapter 18

2. Mechanics of ventilation
Pressure and pumps

3. Thoracic cavity

4. Pleural cavities Fig. 17-11 Diaphragm Right pleural cavity
Left pleural cavity
Fig

5. Pleural cavities Right lung Pericardial cavity Right pleural cavity
Pleural membranes
Left pleural cavity
Left
Heart
Fig. 17-2

6. Fig. 17-12 Intrapleural space Pleural membranes Diaphragm P = –3 mm Hg
Ribs
Fig

7. Inspiration and expiration

8. The rib cage expands slightly.
Pneumothorax
P = Patm
Lung collapses to unstretched size
Knife
Intrapleural space
Pleural membranes
If the sealed pleural cavity is opened to the atmosphere, air flows in.
The rib cage expands slightly.
Air
Fig

9. Alveolar gas composition
Atmospheric gases

10. Partial pressures

11. Alveolar ventilation

12. Alveolar ventilation 2 3 4 1
150
150 mL
350
2700 mL
2200 mL
Fig

13. Alveolar gases