Which statement correctly defines inspiratory capacity (IC)?

Which statement correctly defines inspiratory capacity (IC)?

• A. The amount of air remaining after a maximal expiration.
• B. The total lung capacity.
• C. The maximum amount of air that can be inhaled following a normal expiration, calculated as TV + IRV.
• D. The amount of air remaining after a normal expiration.

Answer: (C)

Inspiratory capacity is the amount of air you can inhale after a normal exhalation. It’s the deep breath you take beyond your regular breath, and it equals tidal volume plus inspiratory reserve volume (IC = TV + IRV). This captures the idea of how much air the lungs can draw in above a typical breath. This differs from residual volume (air left after a maximal expiration), functional residual capacity (air left after a normal expiration), and total lung capacity (the sum of all lung volumes). So the statement describing IC as the maximum air you can inhale after a normal expiration and calculated as TV + IRV is the correct one.

Inspiratory capacity is the amount of air you can inhale after a normal exhalation. It’s the deep breath you take beyond your regular breath, and it equals tidal volume plus inspiratory reserve volume (IC = TV + IRV). This captures the idea of how much air the lungs can draw in above a typical breath.

This differs from residual volume (air left after a maximal expiration), functional residual capacity (air left after a normal expiration), and total lung capacity (the sum of all lung volumes). So the statement describing IC as the maximum air you can inhale after a normal expiration and calculated as TV + IRV is the correct one.