Lung Volumes DSA

Question 1

Residual volume

Answer 1

RV
Volume of air that cannot be forced out no matter how hard one tries.
Cannot be determined via spiro.

Question 2

Tidal volume

Answer 2

Vt
The amount of air inspired or expired in a single breathe.
Will vary, but normally 500 ml.

Question 3

Inspiratory reserve volume

Answer 3

IRV

Volume of air breathed above Vt.

Question 4

Expiratory reserve volume

Answer 4

ERV
Volume of air that can be forced out in addition to Vt.
Requires expiratory muscles.

Question 5

Vital capacity

Answer 5

VC
Amount of air that can be maximally inspired followed by maximal expiration.
VC = IRV + Vt + ERV

Question 6

Inspiratory capacity

Answer 6

IC
Capacity of air that can be maximally inspired following a normal exhale.
IC = Vt + IRV

Question 7

Functional residual capacity

Answer 7

FRC
Amount of air that remains in the lungs following a normal expiration.
FRC = ERV + RV
Cannot be determined be spiro.
Helps prevent lung collapse.

Question 8

Total lung capacity

Answer 8

TLC
Max volume to which lungs can be expanded with greatest effort.
TLC = IC + FRC = VC + RV = ERV + RV + IRV +Vt