And how to know if you need one! While it gets lost easily in the noise of the WIC, the truth is that the wedding is the ceremony, and the reception is the party that happens after the wedding. In a similar way, the rehearsal dinner has become a big deal in the American Wedding Machine, and the rehearsal itself is often an afterthought.
Residual volume (RV) is a lung volume representing the amount of air left in the lungs after a forced exhalation; this volume cannot be measured, only calculated.
Exhalation, similar to inhalation, consists of the standard tidal volume as well as the potential for an expiratory resolve volume (ERV). The ERV can be thought of as the amount of air that is pushed out after a normal breath if you were to exhale as much as possible. Another commonly used term is vital capacity (VC).