Respiratory Volumes and Capacities

Tidal Volume

Amount of air that you move in and out of your lungs while breathing normally

500mL

Normal Tidal Volume

What affects respiratory capacity?

Person’s size, sex, age physical condition

Inspiratory Capacity

Amount of air drawn into lungs after a normal respiration cycle

3000mL

Normal Inspiratory Volume

Inspiratory Reserve Volume

Amount of air that can be taken in forcibly over the tidal volume

3,100mL

Normal Inspiratory Reserve Volume

Expiratory Reserve Volume

Amount of air that can be forcibly exhaled after a tidal expiration

Normal Expiratory Reserve Volume

1,200mL

Residual Volume

Air remaining in lung after expiration

Allows gas exchange to go on continuously, even between breaths, and helps keep alveoli open

Normal Residual Volume

1,200 mL

Total Lung Capacity

Maximum amount of air in lungs after maximum inspiration

Normal Total Lung Capacity

5,000 mL

Vital Capacity

Greatest volume of air that can be expelled from the lungs after taking the deepest possible breath

=TV + IRV + ERV

4,800 ml in men

3,100 ml in women

Vital Capacity Volume for men

4,800 mL

Vital Capacity Volume for women

3,100 mL

Dead Space Volume

Air that remains in conducting zone and never reaches alveoli

Normal Dead Space Volume

150 mL

Functional Residual Capacity

Amount of air remaining in lungs after normal respiratory cycle

Functional Volume

Air that actually reaches the respiratory zone

Normal Functional Volume

350 mL

Spirometer

Device used to measure respiratory capacities