Dream Big with the 2025 CPSGT Practice Exam – Snooze Your Way to Success!

Melatonin is the primary hormone associated with regulating sleep-wake cycles. It is produced in the pineal gland in response to darkness, signaling the body that it is time to sleep. This hormone plays a significant role in maintaining circadian rhythms, promoting feelings of drowsiness and lowering body temperature, which prepares the body for sleep.

While cortisol, serotonin, and adrenaline are all hormones involved in various physiological processes, they do not have the same direct influence on sleep-wake cycles as melatonin. Cortisol is related to stress responses and typically peaks in the morning to help wakefulness. Serotonin is a precursor to melatonin and is involved in mood regulation, but it doesn't directly regulate sleep-wake cycles. Adrenaline is associated with the fight-or-flight response and can actually inhibit sleep. Thus, melatonin stands out as the hormone specifically linked to sleep induction and circadian rhythm regulation.

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