Scientists Studied the Thermoregulatory and Osmoregulatory Responses in Exercising Human

Multiple Choice

Scientists studied the thermoregulatory and osmoregulatory responses in exercising human subjects who were experiencing different levels of dehydration (0%, 3%, 5%, and 7% based on body weight) . After exercise, the subjects' body temperatures, sweating rates, and blood solute concentrations were measured. Their results are shown in these three graphs. Note that only sweating rate was measured after each bout of exercise. Body temperature was measured after the first two bouts of exercise, and blood solutes after only the first bout of exercise.
Source: Adapted from Sawka, M. N., Young, A. J., Francesconi, R. P., Muza, S. R., & Pandolf, K. B. (1985) . Thermoregulatory and blood responses during exercise at graded hypohydration levels. J Appl Physiol, 59, 1394-1402.
-Predict what happens after the study, when the dehydrated subjects become rehydrated.

A) Blood solute concentrations should increase.
B) Their pituitary glands should begin to secrete ADH.
C) Collecting duct cells should begin to reabsorb less water.
D) The amount of water excreted should decrease.