Melatonin is the primary hormone that triggers sleepiness.
How Melatonin Works
Melatonin plays a crucial role in regulating our sleep-wake cycle, also known as the circadian rhythm. This rhythm is our body's internal clock that helps us stay awake during the day and makes us feel sleepy at night.
Here's how melatonin contributes to sleep:
- Low Levels During the Day: During daylight hours, the levels of melatonin in our bodies are low. This helps us remain alert and active.
- Increased Levels at Night: As darkness approaches, our pineal gland starts to secrete more melatonin.
- This surge in melatonin sends signals to our body that it's time to prepare for sleep.
- The light-sensitive SCN (suprachiasmatic nucleus) projects to the pineal gland through multiple synapses to drive the circadian rhythm of melatonin production.
The Science Behind It:
The reference provided confirms this mechanism, stating: "Melatonin is the hormone best known to affect sleep, being low during the daytime but rising once darkness sets in, leading to sleep. Melatonin is secreted by the pineal gland, to which the SCN projects via multiple synapses to drive the Circadian rhythm of production of this hormone.07-Jul-2022"
Practical Insights
- Exposure to Light: Exposure to bright light, especially blue light from electronic devices, can suppress melatonin production, making it harder to fall asleep. This is why it's advisable to avoid screens before bedtime.
- Timing of Melatonin Release: Melatonin secretion typically starts a couple of hours before our normal bedtime. This is why establishing a regular sleep schedule is important to take full advantage of the sleep-inducing effects of the hormone.
- Melatonin Supplements: In some cases, a doctor might recommend melatonin supplements to help with sleep issues. However, these should be used under the guidance of a healthcare professional.
Conclusion
In summary, the hormone that primarily triggers sleepiness is melatonin. Its levels fluctuate throughout the day, with low amounts during the day and higher concentrations as darkness sets in, thereby preparing the body for sleep.
