Pulmonary

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Lung Volumes

Mechanics of Breathing

Lung Volumes

  • Tidal Volume (TV): amount of air inhaled and exhaled during normal, resting breath

  • Inspiratory Reserve Volume (IRV): the volume of air that can be inhaled with maximum effort after normal inhalation

  • Experatory Reserve Volume (ERV): the volume of air that can be forcefully exhaled after normal exhalation

  • Residual Volume (RV): amount of air remaining in the lungs after maximal exhalation

 

Lung Capacities

  • Inspiratory Capacity (IC): total volume of air that can be inhaled from resting expiratory level (TV + IRV)
  • Functional Residual Capacity (FRC): volume of air remaining in the lungs after a normal exhalation (ERV + RV)
  • Vital Capacity (VC): maximal amount of air that can be exhaled after maximal inhalation (IRV + TV + ERV)
  • Total Lung Capacity (TLC): total volume of air that the lungs can hold (RV + ERV + TV + IRV)
  • Functional Expiratory Volume in 1 sec (FEV1): how m uch air someone can forcefully exhale in 1 second
    • between 80% and 120% of the predicted value for a person's age, sex, height, and ethnicity
  • Forced Vital Capacity (FVC): measurement of lung function assessment during spirometry testing
    • Normal: Males = 4.75 to 5.5 liters, Females = 3.25 to 3.75 liters