Sleeping is part of our natural daily rhythm. Our eyes close, our bodies relax. We do not respond to light or noise. Everything about us seems to slow down.
Everything, that is, except our brains. How do scientists know this? They attach a special machine to sleeping patients. This machine records brain waves.
Scientists found that there are several stages of sleep. During one stage of sleep, called REM sleep (rapid eye movement sleep), our brains can be as active as they are when we are awake. We usually have three to five periods of REM sleep per night. This is when we have most of our dreams.
Surprisingly, scientists don’t know exactly why we sleep. However, they have some good ideas. Many think that sleeping gives our body a “timeout” so it can repair and build itself. Some chemicals that make you grow are released when you sleep. Other chemicals that help you fight disease are also active when you rest.
Sleeping may also be important for learning. Some studies show that people remember things better after they “sleep on it”.
You usually wake up in the morning feeling rested and refreshed. That is, unless you’ve had a scary dream. In fact, your heart may still be pounding from a nightmare.
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"Why do people need to sleep?" was posted on Thursday, August 9th, 2007 at 9:12 pm.