Sleep And Dream
Essay by 24 • September 17, 2010 • 596 Words (3 Pages) • 2,765 Views
Sleep and Dreams
Sleep is a behavioral state characterized by little physical activity and almost no awareness of the outside world. Sleep is actually made up of two separate and distinctly different states called REM sleep (rapid eye movement) and NREM sleep (non-rapid eye movement). With NREM sleep it is further divided into stage 1-4 based on the size and the speed of the brain waves. Step one is the stage when you drift off to sleep or doze off. For example people doze off in class because you are bored and have nothing to do but listen to the teacher talk. Some parents may call it a cat nape when their kids go to sleep for about ten minutes or so. The second stage is called an intermediate stage of sleep. That is when
the sleeper will gradually descend deeper into sleep, becoming more and more detached from the outside world and progressively more difficult to awaken. Stage three is the beginning of deep sleep, occurring about thirty to forty five minutes after you first fall asleep. The deepest sleep occurs in Stage four. Stage three and four has the biggest and slowest brain wave. REM sleep, a mentally active period during which dreaming occurs, provided a biological explanation for this phenomenon. Scientists found that brain activity during REM sleep begins in the pons, a structure in the brainstem, and neighboring midbrain regions. The pons sends signals to the thalamus and to the cerebral cortex, which is responsible for most thought processes. There are several myths about sleep. For one, how much sleep a person should get? According to our text book people should sleep for at least eight hours to maintain sound mental and physical health. But every one doesn't get the chance to sleep for that amount of time. There is no normal amount of time you should sleep. Everyone is not the same. For one I might sleep for five hours and feel refreshed enough to work another shift. Other hand my cousin might need more then eight hours of sleep to feel
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