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

Question

Quizplus · Accepted Answer

The organ referred to is the suprachiasmatic nucleus in the hypothalamus, which receives input from photosensitive cells in the eyes and helps regulate our sleep-wake cycle. When it's dark, the suprachiasmatic nucleus signals to the pineal gland to release melatonin, making us feel sleepier.

What Aspect of Circadian Rhythms Might Explain Why We Tend