Values will change with position, age, sex, height, effort, and altitude. Most volumes are decreased, but flow rates are normal or increased. Tidal volume is the volume inspired and expired during normal respirations. Inspiratory reserve volume is the additional volume that can be inspired with maximum effort after a normal inspiration. Residual volume is the volume left in the lungs after a maximal expiration.
Vital capacity is the maximum volume that can be expired after a maximal inspiration.
Total lung capacity is the volume in lungs at the end of a maximal inspiration. Forced vital capacity is the maximum volume of gas that can be expired forcefully after a maximum inspiration. FEV 1 . Forced expired volume is the volume of gas expired during the first second of a FVC maneuver. Forced expiratory flow is less dependent on effort, more dependent on compliance of airways.