1. Respiratory Physiology - introduction Daniel Hodyc Department of Physiology UK 2.LF

2. 1. Pulmonary Ventilation 2. Mechanics of Breathing 3. Ventilation/perfusion ratio, regulation 4. Regulation of Breathing Respiratory Physiology

3. 1. Pulmonary ventilation - transport of gases to alveoli 2. Pulmonary diffusion factors determining gas transport across the membrane 3. Perfusion 4. Ventilation/perfusion ratio Gas transport in lungs

4. 1. Partial pressure 2. Lung volumes and capacities 3. Alveolar ventilation 4. Anatomical and functional death space, effective ventilation Pulmonary ventilation

5. Partial pressure of the gas - in determined by its concentration in the mixture and by the overall pressure of the gas mixture P atm O 2 = P atm * FO 2 P atm O 2 = 740 torr * 0,21 - in the liquid - partial pressure of the gas component, which is balanced with the liquid

6. Lung volumes and capacities tidal volume inspiratory reserve volume expiratory reserve volume residual volume

7. Lung volumes and capacities Spirometer - measurement of lung volumes - measurement of the oxygen consumption

8. Measurement of residual volume and FRC - helium equilibration method Uneven ventilationInaccurate measurement C 1 * V 1 C 2 * (V 1 + V 2 )

9. Measurement of functional residual capacity - pletysmograph Boyl´s law: P * V = const P 1 * V 1 = P 1 ´ * (V 1 - dV) P 2 * V 2 = P 2 ´ * (V 2 + dV) V 2 = FRC P 1 * V 1 P 2 * V 2

10. Air composition in respiratory system

11. Alveolar ventilation 0202 C0 2 ventilation of anatomic dead space inspiration expiration

12. Alveolar ventilation

13. Relationship between tidal volume, frequency and effective ventilation Minute ventilation ml/min Tidal volume ml Frekvency c/s Alveolar Ventilation ml/min Ventilation Anat. dead space ml/min Effective ventilation % 8000250323200480040 8000500165600240070 8000100086800120085 Why not to breathe with minimal frequency? Work of breathing

14. Measurement of anatomic dead space Fowler´s method - insp - 100% 0 2 - exp - nitrogen concentration measurement VDVD

15. Physiologic dead space ventilated but not perfused alveoli P E CO 2 P A CO 2 P a CO 2 VTVT VAVA V Aeff ventilation of anatomic dead space ventilation of physiologic dead space VDVD VTVT = P aCO2 P ECO2 P aCO2 - Bohr equation

16. Uneven ventilation The worst ventilation - apical parts

17. - lung volumes measurable by spirometer (VT,IRV,ERV) - RV, FRC - measurable by He, plethysmograph - anatomic dead space - effective ventilation and respiratory frequency, work of breathing - physiologic dead space, Summary

18. Thank you for your attention Pictures and schemes – J.B.West - Respiratory Physiology, LWW - Guyton, Hall - Textbook of Medical Physiology, 11th