The Science Behind Why We Sleep—Adenosine and Melatonin

Updated on January 5, 2018

Why Do We Sleep?

We spend one-third of our lives sleeping. We know that without sleep, we don't feel well. Research is making it clear that lack of sleep is linked to many heath risks. It is as important to our well-being as nutrition and exercise.

We may get tired at different times of the day. Some of us fall asleep early in the evening, some late at night, insomniacs struggle to get to sleep at all - but eventually, we all fall asleep. What is the secret of how we slip into this essential state? Scientists have found that two important cycles regulate our sleep—the homeostatic sleep drive and the circadian signal. These cycles are controlled by two vital components —adenosine and melatonin.

Why Does Caffeine Keep You Awake?

Caffeine is a substance that can block the adenosine receptors in our bodies, thereby interfering with the accumulation of adenosine. Because you have less adenosine built up in your system, you feel energized and less fatigued.

The Homeostatic Sleep Drive Process

The homeostatic sleep drive process regulates the drive to sleep based on the amount of time we're awake and how much energy we're expending. The chemical adenosine binds to adenosine receptors during waking hours. The more you do and the longer you're awake, the more adenosine you accumulate, making you feel tired. It's your body's way of saying you've done enough, and it's time to quit. While you sleep, this chemical is broken down and adenosine levels decrease. Therefore, scientists feel that adenosine is the way the body keeps track of how much sleep you've gotten, and how much sleep you need. If you don't get enough sleep, the adenosine in your body is still remaining when you wake up, making you feel groggy. The next night you may sleep longer to rid your body of the extra accumulation of adenosine.

Turn Off Electronic Devices in the Bedroom!

Did you know that having a light on in the bedroom interferes with your sleep? Scientists are even concerned about the light emitted from our electronic devices such as smart phones, laptops, tablets and E-readers. They feel that light in the bedroom can completely distort your natural sleep cycle. Why? Because light interferes with your body's ability to produce melatonin. Scientists recommend that if you want a good night's sleep, turn off those electronic gadgets in your bedroom before retiring for the night!

The Circadian Process

The circadian process is regulated by the a tiny internal biological clock located in the hypothalamus called the suprachiasmatic nucleus (SCN). This structure receives light waves from the eye directly through the optic nerve. This Light resets the clock to correspond to the day-night cycle. Signals from the SCN travel to the pineal gland which switches off the production of melatonin during day, and increases it during night. Similar to adenosine, the build up of melatonin in our bodies makes us feel sleepy. This is why Melatonin is often taken as a natural sleep aid, and is successful for many people.

It All Comes Together

This combination of melatonin from the circadian system and adenosine from the homeostatic system normally peak together around 9 P.M. signaling the body that it's time to sleep. If everything is working as nature intended, we drift off peacefully to a good nights sleep shortly thereafter.

Pleasant Dreams!

Did You Know That Lack Of Sleep Puts You At Risk For:

  • Heart attack
  • Heart failure
  • Irregular heartbeat
  • High blood pressure
  • Stroke
  • Diabetes

Having Trouble Sleeping? Try These Tips!

Questions & Answers

    © 2012 Margaret Perrottet

    Comments

      0 of 8192 characters used
      Post Comment

      • nicolas31 profile image

        nicolas31 6 weeks ago

        How long does it take for melatonin to work http://hlthask.com/how-long-does-it-take-for-melat...

        I found a night mask has really helped my sleep pattern. Don't need melatonin now.

      • mperrottet profile image
        Author

        Margaret Perrottet 4 years ago from Pennsauken, NJ

        epbrooks - thanks so much for taking the time to comment and for the vote up - I really appreciate it.

      • epbooks profile image

        Elizabeth Parker 4 years ago from Las Vegas, NV

        Very detailed hub. Interesting how all of this ties together. Voted up!

      • mperrottet profile image
        Author

        Margaret Perrottet 4 years ago from Pennsauken, NJ

        Nationette - Glad you found this interesting. Thanks for taking the time to comment.

      • Nationette profile image

        Jackie DelMonte 4 years ago from Nashua, NH

        so so so so interesting and useful to know. i have had sleep inconsistency issues since probably second grade! cheers on the info, thank you!

      • mperrottet profile image
        Author

        Margaret Perrottet 5 years ago from Pennsauken, NJ

        Deborah-Diane - So glad you found this useful. Thanks for reading and taking the time to comment.

      • mperrottet profile image
        Author

        Margaret Perrottet 5 years ago from Pennsauken, NJ

        TravelinJack - You're right - sometimes sleep is such delicious escape from things. Thanks so much for stopping by!

      • Deborah-Diane profile image

        Deborah-Diane 5 years ago from Orange County, California

        Really useful information on the science of sleep!

      • TravelinJack profile image

        Jack Baumann 5 years ago from St. Louis, Missouri

        We sleep because its life little break from the hardship of the day!!

      • mperrottet profile image
        Author

        Margaret Perrottet 5 years ago from Pennsauken, NJ

        Peggy - You're right - I should have factored HubPages in! Thanks for reading, voting and sharing.

      • Peggy W profile image

        Peggy Woods 5 years ago from Houston, Texas

        Nice to know the science behind what makes us sleepy. I agree with others who have already commented that what is not factored into this is HubPages. Haha! Up, useful and interesting votes and will share.

      • mperrottet profile image
        Author

        Margaret Perrottet 5 years ago from Pennsauken, NJ

        THEmikeLO - thanks so much for stopping by and taking the time to read and comment.

      • THEmikeLO profile image

        THEmikeLO 5 years ago

        Thank you for this information! I never new the true meaning as to why caffeine kept me awake. Great hub!

      • mperrottet profile image
        Author

        Margaret Perrottet 5 years ago from Pennsauken, NJ

        Kasman - perhaps you're working out too close to the time you're trying to sleep. I've read that if you exercise, it should be many hours before going to bed. Thanks so much for reading and voting - I greatly appreciate it!

      • Kasman profile image

        Kas 5 years ago from Bartlett, Tennessee

        I'm very intrigued by this. I usually struggle sleeping myself. It takes an act of God sometimes to help me stay asleep for a full 8 hours honestly. When I work out, it's even worse. Thanks so much for taking the time to explain how it all works and giving me some tips on how to drop at night!

        Very well written and I'm voting up!

      • mperrottet profile image
        Author

        Margaret Perrottet 5 years ago from Pennsauken, NJ

        rajan- Glad you found this interesting. They're doing lots of studies on sleep these days, and are finding out how critical it is to your health. Thanks so much for stopping by, voting and sharing.

      • rajan jolly profile image

        Rajan Singh Jolly 5 years ago from From Mumbai, presently in Jalandhar,INDIA.

        Thanks for sharing this useful and interesting information Margaret.

        Voted up, useful and shared.

      • vinayak1000 profile image

        vinayak1000 5 years ago from Minneapolis

        Oh yeah!! Should have guessed that. Thanks a lot.

      • mperrottet profile image
        Author

        Margaret Perrottet 5 years ago from Pennsauken, NJ

        vinayak1000 - thanks so much for the votes. You can easily link to other hubs by using the link capsule as I did under "Some Other Sleep Related Hubs".

      • vinayak1000 profile image

        vinayak1000 5 years ago from Minneapolis

        Voted up and Useful. By the way, how do you link to hubs??

      • mperrottet profile image
        Author

        Margaret Perrottet 5 years ago from Pennsauken, NJ

        Thanks for reading and sharing, Au fait. I'll link to your hubs as well.

      • Au fait profile image

        C E Clark 5 years ago from North Texas

        Very interesting article and ties in well with my own hubs on sleep. I've already put a link for this hub in my hub, "Not Enough Sleep Will Make You Fat," and plan to put links to this hub in my other hubs relating to sleep. Voted up, interesting and useful. Will share!

      • mperrottet profile image
        Author

        Margaret Perrottet 5 years ago from Pennsauken, NJ

        From what I've read, it's difficult to get a good sleep in four hours. My husband worked night shift for years, and would sleep from 8:00PM to 12 midnight, go to work, then sleep again from 12:00 PM to 4:00. I don't think he ever felt truly rested with that sleep cycle. My guess is that it probably stops you from getting into a really deep sleep, but I'd have to research it. Thanks so much for stopping by and asking an interesting questions, Easy Exercise.

      • Easy Exercise profile image

        Kelly A Burnett 5 years ago from United States

        Can some people really train themsselves to sleep only 4 hours and still be healthy? If they do, will they still have two types of sleep?

      • mperrottet profile image
        Author

        Margaret Perrottet 5 years ago from Pennsauken, NJ

        Thanks so much for reading and taking the time to comment, Annamie. Glad you found this article useful.

      • profile image

        Annamie Cureteyz 5 years ago

        And now I know! This is such a very informative post, I honestly don’t have any idea about things and issues concerning sleep but now I know!! Thank you for sharing this, keep posting!

      • mperrottet profile image
        Author

        Margaret Perrottet 5 years ago from Pennsauken, NJ

        Thanks BlissfulWriter - I enjoy yours as well!

      • BlissfulWriter profile image

        BlissfulWriter 5 years ago

        I like your scientific articles.

      • mperrottet profile image
        Author

        Margaret Perrottet 5 years ago from Pennsauken, NJ

        @sisterkaite - Welcome to HubPages - I see you just joined. I look forward to reading your hubs!

      • sisterkaite profile image

        Sister Kaite Delaney 5 years ago from Marco Island, FL

        Well written article and I appreciate this, especially in science. Thank you for such good presentation and references.

      • mperrottet profile image
        Author

        Margaret Perrottet 5 years ago from Pennsauken, NJ

        @healthylife2 - You may want to boost your exercise level up to increase the adenosine, or take a melatonin supplement. I've heard that you need to be somewhat careful with taking melatonin, as it can cause nightmares. Thanks so much for reading and commenting!

      • healthylife2 profile image

        Healthy Life 5 years ago from Connecticut, USA

        Interesting hub describing the chemical process involved with sleep. I think I have a shortage of these chemicals and wake up often during the night but am working on it.Thanks for the useful information.

      • mperrottet profile image
        Author

        Margaret Perrottet 5 years ago from Pennsauken, NJ

        Thanks for reading and commenting, Kris. I don't think people realize how vital sleep is to your health.

      • Kris Heeter profile image

        Kris Heeter 5 years ago from Indiana

        Very nice fact-filled hub! Sleep is so critical for our health and well-being and most of us don't get enough! Nicely done:)

      • mperrottet profile image
        Author

        Margaret Perrottet 5 years ago from Pennsauken, NJ

        Thanks for reading and commenting, ChristyWrites.

      • ChristyWrites profile image

        Christy Birmingham 5 years ago from British Columbia, Canada

        A lot of useful points here. While I am always hearing about how much sleep we need, I had not thought much about WHY we sleep. Thanks!

      • mperrottet profile image
        Author

        Margaret Perrottet 5 years ago from Pennsauken, NJ

        So glad you found it interesting, Olde Cashmere - thanks for reading!

      • profile image

        Olde Cashmere 5 years ago

        Thank you for writing this interesting article. I enjoyed learning about the facts and reasons for sleep. Voting this up, useful, and interesting :)

      • mperrottet profile image
        Author

        Margaret Perrottet 5 years ago from Pennsauken, NJ

        Thanks for taking the time to read, comment and vote, Stephanie. Kids need more sleep than adults, so nag away!

      • Stephanie Henkel profile image

        Stephanie Henkel 5 years ago from USA

        I love the interesting facts about sleep that you've included here, and I especially like your explanation of the science of sleep. Now I have some facts to back me up when I nag my granddaughter to get a good night's sleep! :) Good hub, voted up, useful and interesting!

      • mperrottet profile image
        Author

        Margaret Perrottet 5 years ago from Pennsauken, NJ

        Good to see you stopping by, shiningirisheyes, and thanks for the comment.

      • mperrottet profile image
        Author

        Margaret Perrottet 5 years ago from Pennsauken, NJ

        Yes, ignugent17 - I was amazed when doing research how important it is to get a good night's sleep. It's as important as eating well and getting exercise, but does not get the same attention paid to it. Thanks for reading and commenting!

      • mperrottet profile image
        Author

        Margaret Perrottet 5 years ago from Pennsauken, NJ

        Thanks for reading and the votes, CyberShelley. It's greatly appreciated!

      • shiningirisheyes profile image

        Shining Irish Eyes 5 years ago from Upstate, New York

        Excellent research on the subject of sleep. I am amazed as well the deadly diseases that can be caused by lack of sleep. Visious cycle once you are trapped in it.

      • profile image

        ignugent17 5 years ago

        Sleeping is really important and now I understand why I need to drink coffee to keep me awake. Thank you very much for your information very interesting.

      • CyberShelley profile image

        Shelley Watson 5 years ago

        What a fantastic, beautifully laid out hub with great information. Such a pleasure to read. Up, interesting and shared!

      • mperrottet profile image
        Author

        Margaret Perrottet 5 years ago from Pennsauken, NJ

        Yeah, I'm having the same problem. I think HubPages blocks my adenosine receptor. Thanks for reading and commenting.

      • Gamerelated profile image

        Gamerelated 5 years ago from California

        Hello mperrottet, I was reading this last night too because I couldn't sleep. I think there is a third process contributing to my sleep cycle called HubPages. Its been keeping me up late recently. Good work on this article. I look forward to reading more.

      • mperrottet profile image
        Author

        Margaret Perrottet 5 years ago from Pennsauken, NJ

        It is amazing. Everything is so beautifully balanced.

      • profile image

        bob 5 years ago

        Interesting hub. Amazing how the body regulates itself.

      working