Respiratory System Lung Volumes and Capacities

Question 1

Tidal Volume (TV)

Answer 1

The amount of air that enters the lungs in a single inhalation or leaves the lungs in a single exhalation of quiet breathing. In an adult this is normally 500 mL

Question 2

Inspiratory Reserve Volume (IRV)

Answer 2

The amount of air that can be forcibly inhaled after a normal inspiration. Also called ‘complemental air’; generally measures around 3,000 mL

Question 3

Expiratory Reserve Volume (ERV)

Answer 3

The amount of air that can be forcibly exhaled after a normal quiet exhalation. This is also called ‘supplemental air’; approximately 1,000 mL

Question 4

Residual Volume (RV)

Answer 4

The air remaining in the lungs after a forced exhalation; about 1,5000 mL in the adult

Question 5

Inspiratory Capacity (IC)

Answer 5

The volume of air inhaled after a normal exhale

Question 6

Functional Residual Capacity (FRC)

Answer 6

The air that remains in the lungs after a normal exhalation has taken place

Question 7

Vital Capacity (VC)

Answer 7

The total volume of air that can be exhaled after a maximum inhalation. This amount will be equal to the sum of TV, IRV, and ERV

Question 8

Total Lung Capacity (TLC)

Answer 8

The volume of air in the lungs after a maximal inhalation