If chest barely moves during inhalation, even if the respiratory rate is normal, you should suspect that minute volume is decreased.

• A. Expiratory reserve volume is decreased
• B. Overall tidal volume is increased
• C. Inspiratory reserve is increased
• D. Minute volume is decreased

Answer: (D)

Minute volume reflects how much air is moved in and out of the lungs each minute, and it depends on two factors: tidal volume (air per breath) and breathing rate (breaths per minute). If you observe that the chest barely rises during inhalation, that indicates a very small tidal volume. If the breathing rate stays normal, the product of tidal volume and rate—the minute volume—will fall. So the most fitting conclusion is that minute volume is decreased. The other ideas don’t align with the observed shallow inhalations: a decreased observable depth isn’t about a reduced expiratory reserve volume, and increasing tidal or inspiratory reserve would produce deeper breaths, not shallow ones, so they wouldn’t match the situation.