What is the normal relationship between vital capacity and tidal volume, in terms of VC being approximately a multiple of Vt?

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Multiple Choice

What is the normal relationship between vital capacity and tidal volume, in terms of VC being approximately a multiple of Vt?

Vital capacity is the total amount of air you can exhale after a maximal inhalation, while tidal volume is the amount moved in a normal breath. In a healthy adult, tidal volume is about 0.5 L, and vital capacity is typically around 4–5 L. Since VC equals tidal volume plus the inspiratory and expiratory reserve volumes (VC = Vt + IRV + ERV), those reserves add up to roughly 3–4 L, giving a VC that is about ten times the normal tidal volume. That’s why the best answer is approximately 10 × Vt.

Vital capacity is the total amount of air you can exhale after a maximal inhalation, while tidal volume is the amount moved in a normal breath. In a healthy adult, tidal volume is about 0.5 L, and vital capacity is typically around 4–5 L. Since VC equals tidal volume plus the inspiratory and expiratory reserve volumes (VC = Vt + IRV + ERV), those reserves add up to roughly 3–4 L, giving a VC that is about ten times the normal tidal volume. That’s why the best answer is approximately 10 × Vt.

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