How is tidal volume expected to change with physical exertion?

Tidal volume is the amount of air that is inhaled or exhaled during normal respiration. With physical exertion, the body's demand for oxygen significantly increases and the production of carbon dioxide rises as well. To meet these metabolic demands, the body uses a variety of mechanisms to enhance breathing efficiency, one of which is the increase in tidal volume.

During exercise, the respiratory system responds by increasing the depth of each breath, leading to an elevated tidal volume. This increase allows for more efficient gas exchange in the lungs, as it helps to increase oxygen uptake and expel carbon dioxide more effectively. As a result, this adaptation is essential for sustaining activity levels and maintaining homeostasis.

The other options do not accurately reflect the physiological changes that occur during physical activity. While tidal volume remains constant during rest, it actively increases during exertion to accommodate the increased metabolic needs. A decrease in tidal volume would compromise the body’s ability to intake sufficient oxygen and expel carbon dioxide, which is counterproductive during physical activity. Random fluctuations do not occur in a predictable or systematic manner during exertion as the body is designed to respond efficiently to changing demands.