What aspect of circadian rhythms might explain why we tend to feel so tired at night?
A) Body temperature bottoms out on Monday mornings.
B) The three biorhythm patterns converge at low points on Mondays.
C) Heart rates typically increase at night.
D) Part of the brain is sensitive to light changes, which then affects our sleepiness.

Question

Quizplus · Accepted Answer

Part of the brain, specifically the suprachiasmatic nucleus (SCN), is sensitive to light changes and sends signals to the pineal gland to produce melatonin, a hormone that helps regulate sleep. As light decreases at night, melatonin production increases, leading to increased drowsiness and sleepiness.

What Aspect of Circadian Rhythms Might Explain Why We Tend