Ventilation and compliance Flashcards
What is TV?
Tidal volume - volume of air breathed in or out of the lungs at each breath
What is ERV?
Expiratory reserve volume - maximum volume of air that can be expelled from the lungs at the end of normal expiration
What is IRV?
Inspiratory reserve volume - maximum volume of air that can be inhaled at the end of a normal inspiration
What is RV?
Residual volume - volume of gas remaining in the lungs at the end of maximal expiration
What is VC?
Vital capacity
Tidal volume + inspiratory reserve volume + expiratory reserve volume
What is TLC?
TENDER LOVING CARE
Total lung capacity
Vital capacity + Residual volume
What is IC?
Inspiratory capacity
Tidal volume + inspiratory reserve volume
What is FRC?
Functional reserve capacity
Expiratory reserve volume + residual volume
What is FEV1?
Forced expiratory volume 1 - forced expired volume in 1 second
What is FEV1:FVC?
Fraction of forced vital capacity expired in 1 second
What is the difference between pulmonary (minute) ventilation and alveolar ventilation?
Pulmonary ventilation is the total air movement in/out of the lungs
Alveolar ventilation is fresh air getting to the alveoli and being available for gas exchange
What unit is ventilation measured in?
L/min
often mL
What is the normal tidal volume for an adult?
500 mL
What is the normal ventilation rate for an adult?
12
Breaths / min
How does Tidal volume and ventilation rate change during exercise?
Tidal volume decreases and breathing rate increases
What is partial pressure?
the pressure that would be exerted by one of the gases in a mixture if it occupied the same volume on its own
True or false
“The partial pressure of a gas in a mixture of gases is equivalent to the percentage of that particular gas in the entire mixture”
False
Partial pressure = percentage of that gas in the mixture, multiplied by the pressure of the whole gaseous mixture
Dalton’s law states that the total pressure of a gas mixture…
is the sum of the pressures of the individual gases
Under normal circumstances, the resting pO2 and pCO2 remains fairly constant
How does hyperventilation and hypoventilation affect these partial pressures?
Hyper-ventilation causes the pO2 to increase and pCO2 to decrease
What is the normal alveolar pO2 and pCO2?
pO2 = 13.3 kPa
pCO2 = 5.3 kPa
What is surfactant?
Fluid produced by type 2 alveolar cells
Surfactant reduces surface tension on the alveolar surface, reducing the tendency for the alveoli to collapse
What is the effect of surfactant production?
Reduces surface tension
Increases lung compliance
Reduces lungs tendency to recoil thus making inspiration easier
What is the law of LaPlace?
P = 2T/r
P - pressure
T - surface tension
r - radius
Describe how surfactant production reduces the likelihood of alveolar collapse
P = 2T/r
Surfactant reduces surface tension T
Value of P therefore decreased
Less pressure means it is less likely to collapse
