Question

The given graph shows various pulmonary air volumes and capacities. What is depicted by X and Y in the graph?

• A. Functional residual capacity and vital capacity
• B. Total lung capacity and inspiratory capacity
• C. Vital capacity and total lung capacity
• D. Inspiratory capacity and functional residual capacity

Answer 1

Answer: (C)

Vital capacity and total lung capacity

C. Vital capacity and total lung capacity

Solution: Here, X = Tidal volume + inspiratory reserve volume + expiratory reserve volume

Vital capacity is calculated by summing tidal volume, inspiratory reserve volume, and expiratory reserve volume. It is the total amount of air exhaled after maximal inhalation.

Here, Y = Inspiratory reserve volume + tidal volume + expiratory reserve volume + residual volume

Total lung capacity is the volume of air in the lungs upon the maximum effort of inspiration. Total lung capacity is calculated by summing inspiratory reserve volume, tidal volume, expiratory reserve volume and residual volume.

So the correct answer is "Vital capacity and total lung capacity".