Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
Lung capacities refer to the different volumes of air that the lungs can hold during various phases of the respiratory cycle. These measurements are crucial for assessing respiratory health and function.
5 Must Know Facts For Your Next Test
Total lung capacity (TLC) is the maximum amount of air the lungs can hold, usually around 6000 mL in an average adult.
Vital capacity (VC) is the total volume of air that can be exhaled after a maximal inhalation, often used to assess pulmonary function.
Functional residual capacity (FRC) represents the volume of air remaining in the lungs after a normal exhalation, helping to keep alveoli open between breaths.
Inspiratory reserve volume (IRV) is the additional air that can be forcibly inhaled after a normal inhalation, indicating lung flexibility and strength.
Residual volume (RV) is the amount of air left in the lungs after a maximal exhalation, which prevents lung collapse and maintains gas exchange.
Review Questions
Related terms
Spirometry: A common test used to measure lung capacities and diagnose respiratory conditions.
Tidal Volume (TV): The amount of air inhaled or exhaled during a normal breath at rest.
Alveolar Ventilation: The exchange of gas between the alveoli and external environment, crucial for effective gas exchange.