Circadian Rhythm: The circadian rhythm is our internal biological clock that regulates various physiological processes, including our sleep-wake cycle.
Melatonin: Melatonin is a hormone produced by the pineal gland in response to darkness. It helps regulate our sleep-wake cycle by promoting drowsiness and maintaining proper timing of sleep.
Adenosine: Adenosine is a chemical compound that accumulates in our brain throughout the day. Its build-up promotes feelings of tiredness and plays a significant role in regulating our sleep drive.