While college students may sometimes be an exception, most humans sleep at night and are awake during the day. What maintains this relationship?
A) The eye relays messages to the brain about light levels, which synchronizes the circadian rhythms to the day-night cycle.
B) People get more exercise during daylight, which promotes alertness and wakefulness.
C) Ambient air temperature is cooler at night, which triggers the body to sleep.
D) Our internal biological clock is synchronized with the day-night cycle when we are born.

Question

Quizplus · Accepted Answer

The eye relays information to the brain about light levels, which is then used to synchronize the circadian rhythms to the day-night cycle. This process is controlled by the suprachiasmatic nucleus (SCN) in the hypothalamus of the brain, which is known as the "master clock" that coordinates our internal biological rhythms with external environmental cues, such as light and darkness.

While College Students May Sometimes Be an Exception, Most Humans