Respiratory System Flashcards
Tidal volume (VT)
500 ml
Amount of air that enters or leaves the lungs in a single respiratory cycle.
Expiratory reserve volume (ERV)
1200 ml
Additional volume that can be expired after a passive expiration.
Residual volume (RV)
1200 ml
Amount of air in the lung after a maximal expiration. This volume cannot be expired.
Functional residual capacity (FRC)
2400 ml
Amount of gas in the lungs at the end of a passive expiration.
Inspiratory reserve volume (IRV)
3100 ml
Additional amount of air that can be inhaled after a normal inspiration.
Inspiratory capacity (IC)
3600 ml
Maximal volume of gas that can be inspired from FRC.
IC = VT + IRV
Vital capacity (VC)
4800 ml
Maximal volume that can be expired after a maximal inspiration.
Total lung capacity (TLC)
6000 ml
Amount of air in the lung after a maximal inspiration.
Dead space (VD)
150 ml
Breathing (respiratory) rate (RR)
15 breaths/min
Minute ventilation (VE)
7500 ml/min
The total volume of gas entering the lungs per minute.
VE = VT x respiratory rate
There is a dot above V in VE.
Alveolar ventilation (VA)
4.2 L/min (or 5.25 L/min if RR: 15 breaths/min)
The volume of gas per unit time that reaches the alveoli.
VA = (VT - dead space) x respiratory rate
There is a dot above V in VA.
Dead space ventilation (VD)
The volume of gas per unit time that does not reach respiratory portions, but instead remains in the airways.
VD = dead space x respiratory rate
There is a dot above V in VD.
Intrapleural pressure and alveolar pressure during inspiration
-6.7 mmHg and -0.7 mmHg
Intrapleural pressure and alveolar pressure during expiration
-3.7 mmHg and 0.7 mmHg
