Q21 - Ventilation Rate vs Tidal Volume During Graded Exercise
Figure Q.21 shows how lung ventilation is affected by physical activity. As the intensity of exercise increases, humans respond to the increased need for gas exchange in two ways: increase in ventilation rate and increase in tidal volume. The experimental data for a well-trained runner on a treadmill are shown in Figure Q.21.
Figure 1.
Using the information and data, determine which of the statements are true or which are false.
A. The increase in ventilation rate is faster than the increase in tidal volume when the treadmill speed increases from 9 km/h to 12 km/h.
B. In intense physical exercise (> 15 km/h treadmill speed), the increase in the ventilatory minute volume is mainly caused by increased ventilation rate.
C. At the treadmill speed of 15 km/h, the ventilatory volume per minute is approximately 120 L.
D. In an adult human, a tidal volume of 0.2 L and ventilation rate of 30 breaths per minute can provide equally effective gas exchange as a tidal volume of 0.6 L and a ventilation rate of 10 breaths per minute.
Question reproduced from IBO 2016, Theoretical Paper A, licensed under CC BY-NC-SA 4.0 - attributed to the International Biology Olympiad. Open the full exam PDF · Community solutions (unofficial)