The given question is incomplete. The complete question is:
In humans, the maintenance of a stable internal temperature is a direct result of___________.
a. detection of and reaction to stimuli in the environment
b. digestion of starches and absorption of protein from the internal environment
c. diffusion of water and excretion of glucose to the external environment
d. transport of ATP and locomotion through the environment
Answer:
a. detection of and reaction to stimuli in the environment
Step-by-step explanation:
Thermoreceptors present in skin layers of the human body sense the deviation of the body temperature from the normal range. As the body temperature rises above normal, the thermoreceptors send signals to the brain which n turn signals dermal blood vessels to dilate and sweat glands to secrete sweat. The heat from the body surface is lost to the surroundings to drop the body temperature towards the normal range.
On the other hand, when the body temperature goes below the normal range, thermoreceptors send signals to the brain which in turn signals dermal blood vessels to constrict to conserve the body heat. If body temperature continues to drop, muscles are signaled to contract involuntarily to generate body heat to raise the body temperature towards the normal range.