Vital capacity is defined as which of the following?

Vital capacity is defined as which of the following?

• A. The amount of air that remains in the lungs after a forced exhalation
• B. The amount of air moved in and out during a normal breath
• C. The maximum air that can be inhaled after a deep breath
• D. The total volume of air that can be exhaled after maximal inhalation

Answer: (D)

Vital capacity is about how much air you can move in and out in one deep breath. It represents the maximum amount you can exhale after taking the deepest possible inhalation, and it equals the sum of inspiratory reserve, tidal volume, and expiratory reserve. Air left in the lungs after a maximal exhale is the residual volume, which is not part of vital capacity. So the best description is the total volume exhaled following a maximal inhalation. In a healthy adult this is typically around 4–5 liters, varying with body size and fitness. The other statements describe residual volume, normal tidal breathing, or the air you can inhale after a normal breath, which are different measures.

Vital capacity is about how much air you can move in and out in one deep breath. It represents the maximum amount you can exhale after taking the deepest possible inhalation, and it equals the sum of inspiratory reserve, tidal volume, and expiratory reserve. Air left in the lungs after a maximal exhale is the residual volume, which is not part of vital capacity. So the best description is the total volume exhaled following a maximal inhalation. In a healthy adult this is typically around 4–5 liters, varying with body size and fitness. The other statements describe residual volume, normal tidal breathing, or the air you can inhale after a normal breath, which are different measures.