Why do we sleep

Why do we sleep?
Time is money. But every day we spend 8 out of 24 hours to sleep. In such a busy world we live in, those precious 8 hours could be spend for a lot of things. However we are all acknowledge at some point that sleep makes us feel refresh. After a good night sleep, we are able to concentrate better and feel happier. The difference between sleep makes us feel better and not having sleep makes us feel terrible explain why sleep might be necessary. Until today, despite our advanced technology, scientists still haven’t fully understand why we do it.
Your body does not totally shut down when you sleep. When you sleep, your consciousness is only reduced or absent, your senses are suspended and your whole body muscles are relaxed. The body ability to react when sleeping is lower than when you are awake, but it is higher than when you are hibernating or in a coma.
Scientists have come up with theories to explain why we sleep. The inactivity theory, one of the earliest theories of sleep, suggests that animals would be able to stay quiet and not draw attention of other remained active animals. Another theory, the energy conservation theory, proposes that by sleeping an individual’s energy demand are reduced, saving energy especially when it is least efficient to search for food. Some other scientists think that somehow sleeping is able to restore what is lost in the body while we are awake and this theory is called the restorative theories.
In mammals and birds, there are two broad types of sleep: Rapid eye movement (REM) and Non-rapid eye movement (NREM or Non-REM). There are differences in physiological and neurological features between two types. Rapid eye movement (REM) sleep is a normal stage of sleep characterized by the rapid and random movement of the eyes. REM sleep normally occurs close to morning. It is considered the lightest stage of sleep due to the activity of the brain’s neurons during this stage is very much alike to that during waking hours. Sexual arousal may occurs during normal night of sleep from one hour to as long three and a half hours during REM.
Unlike REM sleep, there is usually little or no eye movement during NREM. Muscles are not paralyzed as in REM sleep and dreaming is rare during NREM sleep. People who do not go through the sleeping stages properly get stuck in NREM sleep and because muscles are not paralyzed, a person may be able to sleepwalk.
"Many things that we take for granted are affected by sleep," says Raymonde Jean, MD, director of sleep medicine and associate director of critical care at St. Luke’s-Roosevelt Hospital Center in New York City. "If you sleep better, you can certainly live better. It’s pretty clear.". Scientific research suggest that sleep plays an important role in the memory although there are still unsolved questions about the specific role of sleep. The relation between sleep and memory is complex that is not entirely understood. But after studying animal and human, scientists pointed out that the quantity and quality of sleep have a great impact on learning and memory. A sleepless person cannot learn efficiently. Sleep plays an important role in the consolidation of memory, which is essential for learning new information. In 2010, a study of women ages 50 to 79 showed that more deaths occurred in women sleep less than five hours or more than six and a half hours. So sleep also affects quality of life. Another research also indicates that people who get less sleep – six or fewer hours a night- have higher blood levels of inflammatory proteins than those who get more. Inflammation is linked to heart disease, stroke, diabetes, arthritis, and premature aging.
Maybe next time when you go to bed, instead of regretting the amount of time you spend sleeping, try thinking about how much good it will do to you.