Pulmonary volumes and capacities Flashcards
How are pulmonary volumes measured?
Spirometry
What presents the results of spirometry?
Spirogram
How many pulmonary volumes are there?
Four
What are the different pulmonary volumes?
Tidal volume
Inspiratory reserve volume
Expiratory reserve folum
Residual volume
What is the tidal volume?
Volume of air inspired or expired at rest
What is the inspiratory reserve volume?
Extra volume of air over tidal volume that person can breathe in forcefully
What is the expiratory reserve volume?
Extra volume of air over tidal volume that person can breathe out forcefully
What is the residual volume?
Volume of air remaining in lungs after forceful expiration
How many pulmonary capacities are there?
Four
What are the different pulmonary capacities?
Inspiratory capacity
Vital capacity
Functional residual capacity
Total capacity
What is the inspiratory capacity?
Maximum volume of air a person can breathe in forcefully after tidal expiraton
How is the inspiratory capacity calculated?
Tidal volume + inspiratory reserve volume
What is the vital capacity?
Maximum volume of air a person can breathe out forcefully after they’ve breathed in forcefully
How is the vital capacity calculated?
Inspiratory reserve volume + tidal volume + expiratory reserve volume
What is the functional residual capacity?
The volume of air that remains in the lungs after tidal expiration
How is the functional residual capacity calculated?
Expiratory reserve volume + residual volume
What is the total lung capacity?
Maximum volume of air in the lungs after breathing in forcefully
How is the total lung capacity calculated?
Residual volume + expiratory reserve volume + tidal volume + inspiratory reserve volume
What is the normal tidal volume for a young man?
500ml
What is another term for the functional residual capacity?
Resting end-expiratory level
What determines the resting end-expiratory level?
Balance between force pulling chest wall outwards
and force by elastic recoil of lungs pulling them inwards
What is the resting end-expiratory level of a young adult compared to an older adult?
Old adult has a higher resting end-expiratory level
Why does an old adult have a higher resting end-expiratory level than a young adult?
Old adult has less elastin in their lungs
less elastic recoil of lungs
less air expired from lungs
therefore more air left in lungs after expiration