Which calculation can be used to determine Total Lung Capacity (TLC)?

Total Lung Capacity (TLC) encompasses the total volume of air the lungs can hold and is comprised of several distinct volumes. To accurately determine TLC, one must consider all relevant components based on lung volumes.

The correct calculation includes both the Inspiratory Capacity (IC) and Functional Residual Capacity (FRC). IC represents the maximum amount of air that can be inhaled after a normal exhalation, while FRC is the volume of air remaining in the lungs after a normal exhale, comprising both Expiratory Reserve Volume (ERV) and Residual Volume (RV). Therefore, the combination of IC and FRC captures all the air held within the lungs when fully inflated.

This approach to calculating TLC effectively accounts for the entirety of lung volume, illustrating how much air is available in the respiratory system at its fullest extent. The alternative options lack this comprehensive inclusion of necessary lung volumes to effectively determine TLC, thus reinforcing the appropriateness of combining IC and FRC to arrive at the accurate measurement.