Lung Volumes + Capacities Flashcards
Anatomic Dead Space Volume (VD)
Volume of air that occupies the non-respiratory conducting airways
Expiratory Reserve Volume (ERV)
- Maximal volume of air that can be exhaled after a normal tidal exhalation.
- Approximately 15% of the total lung volume
Forced Expiratory Reserve Volume (FEV)
Maximal volume of air exhaled in a specific period of time: usually the 1st, 2nd, and 3rd second of a forced vital capacity maneuver
Forced Vital Capacity (FVC)
The volume of air expired during a forced maximal expiration after a forced maximal inspiration
Functional Residual Capacity (FRC)
- The volume of air in the lungs after normal exhalation
- FRC = ERV + RV
- Approximately 40% of total lung volume
Inspiratory Capacity (IC)
- Maximal Volume of air that can be inspired after a normal tidal expiration
- IC = TV + IRV
- Approximately 60% of the total lung volume
Inspiratory Reserve Volume (IRV)
- Maximal Volume of air that can be inspired after a normal tidal volume inspiration
- Approximately 50% of the total lung volume
Minute Volume Ventilation (VE)
- The volume of air expired in one minute
- VE = TV x respiratory rate
Peak Expiratory Flow (PEF)
Maximum flow of air during the beginning of forced Expiratory maneuver
Residual Volume (RV)
- The volume of gas remaining in the lungs at the end of a maximal expiration
- Approximately 25% of the total lung volume
Tidal Volume (TV)
- Total Volume inspired and expired with each breath during quiet breathing
- Approximately 10% of the total lung volume
Total Lung Capacity (TLC)
- Volume of air in the lungs after a maximal inspiration
- The sum of all lung values
- TLC = RV + VC or TLC = FRC + IC
Vital Capacity (VC)
- The volume change that occurs between maximal inspiration and maximal expiration
- VC = TV + IRV + ERV
- Approximately 75% of the total lung volume