Lung Function Testing Quiz

See Lung Volume. Option D is correct because tidal volume (VT) is the volume of air entering and leaving the lungs with each normal breath. Quiet breathing is usually automatic and needs no deliberate effort, although quiet inspiration still needs respiratory muscle activity. It is called quiet inspiration and quiet expiration. If you then take a deliberately deep breath in, the extra air is the inspiratory reserve volume, and if you then breathe out as far as you can, the extra air is the expiratory reserve volume. Both of these are called forceful breathing, because the person has to consciously move the air. After maximal breathing out, the residual volume remains in the lungs. The sum of the inspiratory reserve volume, tidal volume and expiratory reserve volume is the vital capacity. A memory aid is that tidal is like the tide going in and out each time.

• Tidal volume: air entering and leaving the lungs with each normal breath.
• Extra breath in: inspiratory reserve volume.
• Extra breath out: expiratory reserve volume.
• Left behind: residual volume.

Match each definition to whether the breath is quiet, forceful or incomplete.