Is Sleep Important ? Necessary ?

       

           Hey Guys ! For many of us, the worst moment of everyday goes something like this… ALARM  NOISE ....That noise marks our daily return from the mysterious world that we call sleep. We spend a third of our lives asleep, yet, other than the odd snapshot of a dream here and there,most of us have no idea what happens after we close our eyes. Luckily we’re in good company, because there’salso a lot scientists don’t know about sleep too. For a long time, it was just something that happened, everyone assumed that our brains were hitting the reset button and just turning off for a while. But in the past few decades it’s become clear that sleep might be the single most important behavior that humans and other animals experience. It might seem like we don’t do much while we're sleep, but neuroscience tells a different story.

             

      

           Human sleep patterns are controlled by two competing networks of chemical and electrical signals in the brain. During our waking hours, neurotransmitters released deep within our brain keep our cerebral cortex alert and primed for consciousness.But throughout the day, as our neurons break down ATP for energy, the byproduct adenosine builds up and activates sleep control neurons near the hypothalamus. A special region in the center of our brainacts as our master biological clock. Light sensitive cells in our retinas feed signals deep into that brain region, training neurons to sync up with Earth’s 24 hour cycle ofday and night. These circadian rhythms are the control switch that tells us when to feel sleepy or awake. As the world goes dark, this master switchtells our pineal gland to increase levels of the hormone melatonin in the bloodstream,sort of like a chemical lullaby. Feelings of fatigue set in, body temperature lowers slightly, that heat loss is actually why many of us like to fall asleep with our feet sticking out of the covers, true story! Together all this neurochemistry sends one clear message to our bodies: when it’s dark, it’s time to go to bed. 

            

          Unfortunately, in modern times, darkness is increasingly rare. In the United States, 99 percent of people live in areas that meet standards for light pollution, and we’ve got one person to thank for that: Thomas AlvaEdison. Edison thought sleep was lazy, unhealthy,or inefficient, even though he took several naps a day. But despite that hypocrisy his work , more sleep less view changed our world forever. Illuminating the night became a sign of economic progress, and humankind was no longer at the mercy of nature’s clock. 

    

            Artificial light can have serious effectson our sleep cycle. When we’re exposed to bright light at night, our brain doesn’tknow better than to think the sun is shining. This can be very confusing, preventing the release of melatonin and the onset of sleep. Depression, heart disease, diabetes, and cancer have all been linked to chronic overexposure to artificial light. Until just a couple hundred years ago, it was common for people to fall asleep right after the sun went down, snooze for a while,wake up around midnight, where they would read or study or do other stuff, then go backto sleep until morning. Modern experiments have suggested that if people are kept away from artificial light, their bodies will return to this pattern of first and second sleep, yet most of us insist on sleeping the whole night through. What’s worse, our circadian rhythms are so tuned to day and night that if we stay up past ourusual bedtime, we don’t wake up later, we just tend to sleep less. As a result, we’re massively sleep-deprived.

          Most adults average just six and a half hours a night. Teenagers average just five hours on school nights, which is half of what they need. To fight this chronic exhaustion, weturn to stimulants like caffeine to help our brains ignore that buildup of adenosine, andthen to fight the stimulants, many people rely on alcohol, which just sedates us, itdoesn’t even help with real, restful sleep. This vicious cycle is worth literally billionsof dollars a year. It’s kinda messed up. I still love you though, coffee. So what is sleep for? In short, we’re notreally sure, but we know it’s essential to life. Animals deprived of sleep for a longenough time will have seizures, and can literally die from exhaustion, plus a whopping 15% ofour genes are linked to circadian rhythms. Still, there’s no consensus on exactly whyour bodies need sleep. We’re definitely less active at night, but considering we only burn about 100 fewer calories while sleeping, it’s not a very good energy-savingstrategy overall. We definitely do a lot of cellular repair, protein synthesis, and general biological upkeep while we’re in dreamland, but it’s not like we don’t do that stuffwhen we’re awake too. Another theory says that our bodies use timeasleep to flush out all the neurogarbage, removing waste products that build up in our neurons and brain cells. And, decision-making regions of our brain like the prefrontal cortex,well they don’t get any downtime while we’re awake, like even if you’re totally relaxed and you think your mind is clear, your prefrontal cortex is still prefrontal cortexing. 

           Just try and think about nothing. Go ahead. See? You’re thinking about not thinking. Sleep seems to be the only time for this region to power down and get a break. The greatest benefit of sleep may lie in processing information and consolidating memories from throughout the day, letting the brain do allthe rewiring that is necessary for thinkin’ better. Sleep deprived people do worse whenlearning new tasks and they're less able to process new information, whereas a good night’srest appears to make us more creative so we can come up with solutions to new problemsthat we haven’t seen before. Perhaps the biggest mystery is how sleep evolvedin the first place. Snoozin’ animals are easy targets for predators, so you’d think evolution would have come up with something better. But it hasn’t. There’s no wayto get around the need for sleep. Some animals have come up with interesting ways to deal with the inconvenience of sleeping, though. Dolphins obviously can’t nod off without drowning, so they only sleep with one half of their brain at a time, swimming along using the half of their body that’s still awake. Before baby dolphins learn thattrick, they take adorable little dolphin naps while their parents keep them afloat. Sleep or similar patterns of rest are seenso universally throughout the animal kingdom that they must have an ancient origin, andone clue comes from a tiny, ocean-dwelling worm. Every night, these worms swarm near the surfaceof the ocean to feed, and every day they sink down deep to avoid light and predators. The worms have special daylight-sensing cells on their back, just like the ones in our eyes.When it’s dark, those cells trigger the production of melatonin, just like in ourbrains. As the melatonin builds up, tiny hairs on their bodies stop beating and the wormsbegin to sink, just in time for the sun to come up. As the melatonin disappears throughout the day, the hairs begin beating again and they swim back up to the surface to do it all over again. 

        

         Sleep might have evolved 700 million years ago but ; It's pretty important, so maybe we should all make a little more time for it. I mean just Sleep well properly .