Which of the following is NOT included in vital capacity calculation?

Vital capacity is a measure of the maximum amount of air that can be exhaled after maximal inhalation and typically includes three specific components: tidal volume, inspiratory reserve volume, and expiratory reserve volume.

Tidal volume represents the amount of air inhaled or exhaled during normal breathing. Inspiratory reserve volume is defined as the additional amount of air that can be forcibly inhaled after the inspiration of a normal tidal volume. Expiratory reserve volume is the additional amount of air that can be forcibly exhaled after the expiration of a normal tidal volume.

In contrast, inspiratory capacity is defined as the maximum amount of air that can be inhaled after a normal exhalation, which is calculated by adding tidal volume to inspiratory reserve volume but is not included as a separate component in the calculation of vital capacity itself. Therefore, inspiratory capacity does not fit into the equation for vital capacity, as it is a distinct measurement rather than a component of vital capacity.

This is why inspiratory capacity is the correct answer when identifying the component that is not included in the calculation of vital capacity.