Lung Volumes & Capacities

Question 1

Anatomic dead space volume (VD)

Answer 1

Volume of air that occupies the non-respiratory conducting airways

Question 2

Expiratory reserve volume (ERV)

Answer 2

Maximal volume of air that can be exhaled after a normal tidal exhalation, ~15% of total lung volume

Question 3

Forced expiratory volume (FEV)

Answer 3

Maximal volume of air exhaled in a specified period of time: usually the 1st, 2nd, and 3rd second of a forced vital capacity maneuver

Question 4

Forced vital capacity (FVC)

Answer 4

Volume of air expired during a forced maximal expiration after a forced maximal inspiration

Question 5

Functional residual capacity (FRC)

Answer 5

Volume of air in lungs after normal exhalation, FRC= ERV+RV and is ~40% of total lung volume

Question 6

Inspiratory capacity (IC)

Answer 6

Maximal volume of air that can be inspired after a normal tidal exhalation, IC= TV+IRV and is ~60% of total lung volume

Question 7

Inspiratory reserve volume (IRV)

Answer 7

Maximal volume of air that can be inspired after normal tidal volume inspiration, ~50% of total lung volume

Question 8

Minute volume ventilation (VE)

Answer 8

Volume of air expired in 1 minute, VE= TV x respiratory rate

Question 9

Peak expiratory flow (PEF)

Answer 9

Maximum flow of air during beginning of a forced expiatory maneuver

Question 10

Residual volume (RV)

Answer 10

Volume of gas remaining in the lungs at the end of a maximal expiration, ~25% of total lung volume

Question 11

Tidal volume (TV)

Answer 11

Total volume inspired and expired with each breath during quiet breathing, ~ 10% of total lung volume

Question 12

Total lung capacity (TLC)

Answer 12

Volume of air in the lungs after a maximal inspiration; sum of all lung volumes
TLC= RV+VC or FRC+IC

Question 13

Vital capacity (VC)

Answer 13

Volume change that occurs b/w maximal inspiration and maximal expiration, ~75% of total lung volume, VC= TV+IRV+ERV