Physiology: Lung Volumes and Compliance Flashcards
What is anatomical dead space ?
Volume of gas occupied by conducting airways and not available for gas exchange
What is the anatomical dead space equal too?
~150ml each
What is Tidal Volume?
TV - the volume of air breathed in and out of the lung in each breath
What is Expiratory Reserve Volume?
ERV - Maximum volume of air which can be expelled out the lungs at the end of of a normal expiration
What is Inspiratory Reserve Volume?
IRV - maximum volume of air which can be drawn into the lungs at the end of a normal inspiration
What is the Residual Volume?
RV - The volume of gas at the end of a maximal expiration
What is the Vital Capacity?
VC = Tidal Volume + Inspiratory Reserve Volume + Expiratory Reserve Volume
What is the Total Lung Capacity?
TLC - Vital Capacity + Residual Volume
What is the inspiratory Capacity?
IC - Tidal Volume + the inspiratory reserve volume
What is the Functional Residual Capacity?
FRC - Expiratory Reserve Volume + Residual Volume
What is the FEV1
Forced expired volume in 1 second
What is the FEV1:FVC?
Fraction of Forced Viral Capacity expired in 1 second
What is ventilation?
Movement of air in and out of the lungs
What is Pulmonary Ventilation?
Total movement of air in and out of the lungs
Measured in L/min
What is alveolar Ventilation?
Fresh air getting to the alveoli and therefore is available for gas exchange
Measured in L/min
What happens to ventilation in the sympathetic system?
Rapid breaths meaning less tidal volume and therefore less alveolar ventilation causing Hypo-ventilation
What happens to ventilation in the parasympathetic system?
Slower breaths causing a greater tidal volume causing an increase in alveolar ventilation and therefore Hyper-ventilation
What is Dalton’s Law?
Total Pressure of a gas mixture is the sum of the pressures of the individual gases
What is the definition of Partial Pressure?
Pressure of gas in a mixture of gases is equivalent to the percentage of that particular gas in the entire mixture multiplied by the pressure of the whole gas mixture
Normally expressed in mmHg
What happens to the partial pressure of O2 and CO2 when ventilation is normal?
They remain fairly constant
What happens to Po2 and Pco2 during hyper-ventilation?
Po2 rises to 120mmhg
Pco2 falls to 20mmHg
What happens to Po2 and Pco2 during hypo-ventilation?
Po2 falls to 30mmHg
Pco2 rises to 100mmHg