mL of air per minute. Inspiratory Reserve Volume (IRV): Additional volume of air, a person can inspire by a forcible inspiration. This averages mL to mL. Expiratory Reserve Volume (ERV): Additional volume of air, a person can expire by a forcible expiration.
This averages mL to mL. Figure . Mechanism of breathing showing : (a) inspiration (b) expiration Residual Volume (RV): Volume of air remaining in the lungs even after a forcible expiration. This averages mL to mL.
By adding up a few respiratory volumes described above, one can derive various pulmonary capacities, which can be used in clinical diagnosis. Inspiratory Capacity (IC): Total volume of air a person can inspire after a normal expiration. This includes tidal volume and inspiratory reserve volume ( TV+IRV). Expiratory Capacity (EC): Total volume of air a person can expire after a normal inspiration.
This includes tidal volume and expiratory reserve volume (TV+ERV). Functional Residual Capacity (FRC): Volume of air that will remain in the lungs after a normal expiration. This includes ERV+RV. Vital Capacity (VC): The maximum volume of air a person can breathe in after a forced expiration.
This includes ERV, TV and IRV or the maximum volume of air a person can breathe out after a forced inspiration. Total Lung Capacity (TLC): Total volume of air accommodated in the lungs at the end of a forced inspiration. This includes RV, ERV, TV and IRV or vital capacity + residual volume.