Now You Know

Why Do We Need Sleep?

Humans need sleep; everyone knows that without it, we get cranky, a bit loopy, and then we die. Unfortunately, science has been a little iffy about it; though we understand the negative effects associated with the lack of sleep, no one really knew why those things happened. Now, we're finally getting some insight into what sleep does for our body.

For the first time ever, scientists at the University of Rochester have found one of the reasons our brain needs sleep to survive. Turns out, when we sleep, our brain takes that time to clean out the build up of brain junk we accumulate during our waking hours. Sleep is pretty much necessary for our body's mental street cleaners to come out and do their work.

When cells do their daily cell-type work, they produce waste product. The rest of the body has this waste cleared out by the lymphatic system, but the brain is disconnected from that, so it needs another way to wipe out the waste. The brain has its own garbage men, carried on the waves of cerebrospinal fluid, who surf the leftovers straight down to your liver for elimination. As it turns out, the brain's garbage men move twice as fast when you're sleeping, because your neurons shrink by half, making the fluid channels wider.

"This study shows that the brain has different functional States when asleep and when awake," said University of Rochester researcher Maiken Nedergaard. "In fact, the restorative nature of sleep appears to be the result of the active clearance of the by-products of neural activity that accumulate during wakefulness."

Source: {http://www.themarysue.com/understanding-sleep}

Eight hours of sleep a day seems like a colossal waste of time, doesn't it? After all, in the hectic world we live in, those precious hours could be put to use responding to all those emails, or hitting the spa. So why do we need so much sleep? Dr. Neil B Kavey, director of the Sleep Disorders Danger at Columbia Presbyterian Medical Gender in New York City, offers some clues:

We don't fully understand the importance of sleep. What we do know is that sleep is an anabolic, or building, process. And we think it restores the body's energy supplies that have been depleted through the day's activities.

Sleep is also the time when the body does most of its repair work; muscle tissue is rebuilt and restored. We know, for example, that growth hormone is secreted during sleep. This hormone is important for growth in children, but is also important throughout adulthood in rebuilding tissues.

Theory: A Daily Tune Up- Think of the body as a car. No car can keep going and going and going without a tune up or oil change. If it's not tuned, the car may keep running, but not as smoothly as it did when it was maintained properly. You can think of sleep as your body's daily tune up.

Human beings can function without a full tune up, but they will be in a state of relative sleep deprivation and won't be able to work or to think as well as they do when they're fully rested. It's like an engine that gets only 4 out of 8 spark plugs replaced & then runs sluggishly.

Sleep is also a time for restoring mental energy. We spend all day thinking & creating, and that uses up our energy stores. It is interesting that in dream sleep the brain is actually very active. And this is where things get really theoretical. We're not really sure exactly what dreams accomplish. Some experts believe that dreaming is actually some kind of clearing out process. More sleep researchers think that dreams serve the function of helping to reorganize and store psychological information taken in during the day.

Theory: Not Enough ZZZ's- One of the ways we have of understanding whyvwe need to sleep so much is to look at what happens if we don't get enough sleep. It affects our personalities and our sense of humor. We may become irritable and less tolerant. Parents of small children often say that when they're tired, they get irritated at the antics of children that might amuse them if they were properly rested.

Lack of sleep clearly affects our thinking, or cognitive, processes. A sleep deprived brain is truly running on 4 rather than 8 cylinders. If we're trying to be creative, the motor doesn't work as well. We can perform calculations, but not as quuckly. We're much more likely to make errors. It's because the brain's engine hasn't been replenished.

Sleep deprivation also affects us physically. Our coordination suffers. We lose our ability to do things with agility. Sleep improves muscle tone and skin appearance. With adequate sleep, athletes run better, swim better, and lift more weight. We also see differences in immune responses depending on how much someone sleeps. The amount of sleep a person needs will vary person to person, but most people require 8 hours at least.

Source: {http://www.nbcnews.com/id/3076707/ns/technology_and_science-science/t/why-do-we-need-so-much-sleep/}