Question

Colby had a big work deadline and stayed up most of the night to complete it. On the way to work, he wondered how he was going to make it through the day feeling this tired. By about 11 a.m., he felt much better and far more awake. This is likely due to the _____ in his brain.

Answer 1

Answer:    Decreased levels of melatonin

Explanation:  Melatonin is a substance that is excreted at night and by which the brain sends signals that one should sleep, that is, a man / woman is feeling sleepy. When melatonin secretion decreases, the alertness increases, as is the case with Colby. Melatonin levels decrease at the base of the brain signal regardless of whether or not Colby slept enough the previous night. Feeling tired will induce some other receptors and consequent signals from the brain, but a natural decrease in melatonin throughout the day occurs normally.