Respiration During Exercise (1)
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Transcript of Respiration During Exercise (1)
Respiration During Respiration During Exercise (1) Exercise (1)
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
Pulmonary Ventilation (V)
1. Dead-space ventilation (VD)
• Unused ventilation (like the trachea & bronchi)
• Does not participate in gas exchange
Pulmonary Ventilation (V)
• Anatomical dead space conducting zone
BUT
• Physiological dead space caused by disease
Pulmonary Ventilation (V)
2. Alveolar ventilation (VA)
• Volume of inspired gas that reaches the respiratory zone
V = VA + VD
Total minute ventilation can be subdivided into dead space
ventilation & alveolar ventilation
V +
Pulmonary Volumes & Capacities
•They are measured by spirometry
• Vital Capacity (VC):
– Maximum amount of air that can be expired following a maximum inspiration
InspiratorInspiratory Reserve y Reserve Volume Volume (IRV)(IRV)
Tidal Volume Tidal Volume (TV)(TV)
Residual Residual Volume (RV)Volume (RV)
Expiratory Expiratory Reserve Reserve
Volume (ERV)Volume (ERV)
Pulmonary Volumes & Capacities
Pulmonary Volumes & Capacities
• Residual Volume (RV):
– Air remaining in the lungs after a maximum expiration
InspiratorInspiratory Reserve y Reserve Volume Volume (IRV)(IRV)
Tidal Volume Tidal Volume (TV)(TV)
Residual Residual Volume (RV)Volume (RV)
Expiratory Expiratory Reserve Reserve
Volume (ERV)Volume (ERV)
• Total Lung Capacity (TLC):
– The sum of VC and RV
Pulmonary Volumes & Capacities
InspiratorInspiratory Reserve y Reserve Volume Volume (IRV)(IRV)
Tidal Volume Tidal Volume (TV)(TV)
Residual Residual Volume (RV)Volume (RV)
Expiratory Expiratory Reserve Reserve
Volume (ERV)Volume (ERV)
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
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 = 0.2093– The total pressure of air = 760 mmHg– So PO2 = 0.2093 x 760 = 159 mmHg
Diffusion of GasesDiffusion of GasesFick's Law of Diffusion Fick's Law of Diffusion
The rate of gas transfer (V The rate of gas transfer (V gas) is proportional to gas) is proportional to the tissue area (A), the tissue area (A),
the diffusion coefficient of the diffusion coefficient of the gas (D), the gas (D),
and the difference in the and the difference in the partial pressure of the partial pressure of the gas on the two sides of gas on the two sides of the tissue (P1-P2), the tissue (P1-P2),
And inversely proportional And inversely proportional to the thickness (T)to the thickness (T)
P1P1 P2P2
Diffusion of GasesDiffusion of GasesFick's Law of Diffusion Fick's Law of Diffusion
V gas = A/T x D x (PV gas = A/T x D x (P11 – – PP22))