Measurement of Residual Volume Flashcards
1
Q
What is residual volume?
A
the volume of air left in the lungs after maximal expiration
2
Q
What is the best way to determine residual volume?
A
max expiration then connected to a spirometer of a specified volume, which contains a known concentration of an inert gas marker (e.g. helium) C1
3
Q
When is the new concentration of helium recorded?
A
C2 - once equilibrium has been reached
4
Q
C1V1 =
A
C2V2
5
Q
RV =
A
((C1/C2)-1)*vol of spirometer
6
Q
What is functional residual capacity?
A
volume in the lungs after normal exhalation
