1. Respiration During Exercise (1)

2. Pulmonary Ventilation (V)
The amount of air moved in or out of the lungs per minute
It is the product of tidal volume (VT) and breathing frequency
V= VT x f

3. Pulmonary Ventilation (V)
Dead-space ventilation (VD)
Unused ventilation (like the trachea & bronchi)
Does not participate in gas exchange

4. Pulmonary Ventilation (V)
Anatomical dead space  conducting zone
BUT
Physiological dead space  caused by disease

5. Pulmonary Ventilation (V)
Alveolar ventilation (VA)
Volume of inspired gas that reaches the respiratory zone

6. Total minute ventilation can be subdivided into dead space ventilation & alveolar ventilation
V = VA VD

7. Pulmonary Volumes & Capacities
They are measured by spirometry

8. Pulmonary Volumes & Capacities
Inspiratory Reserve Volume (IRV)
Vital Capacity (VC):
Maximum amount of air that can be expired following a maximum inspiration
Tidal Volume (TV)
Expiratory Reserve Volume (ERV)
Residual Volume (RV)

9. Pulmonary Volumes & Capacities
Inspiratory Reserve Volume (IRV)
Residual Volume (RV):
Air remaining in the lungs after a maximum expiration
Tidal Volume (TV)
Expiratory Reserve Volume (ERV)
Residual Volume (RV)

10. Pulmonary Volumes & Capacities
Inspiratory Reserve Volume (IRV)
Total Lung Capacity (TLC):
The sum of VC and RV
Tidal Volume (TV)
Expiratory Reserve Volume (ERV)
Residual Volume (RV)

11. Partial Pressure of Gases (Dalton’s Law)
The total pressure of a gas mixture is equal to the sum of the pressure that each gas would exert independently

12. Partial Pressure of Gases (Dalton’s Law)
The partial pressure of oxygen (PO2)
Air is 20.93% oxygen
This is expressed as a fraction  20.93/100 =
The total pressure of air = 760 mmHg
So PO2 = x 760 = 159 mmHg

13. Diffusion of Gases Fick's Law of DiffusionP1 P2
Diffusion of Gases
Fick's Law of Diffusion
The rate of gas transfer (V gas) is proportional to the tissue area (A),
the diffusion coefficient of the gas (D),
and the difference in the partial pressure of the gas on the two sides of the tissue (P1-P2),
And inversely proportional to the thickness (T)

14. Diffusion of Gases Fick's Law of Diffusion
V gas = A/T x D x (P1 – P2)