新概念背誦短文:睡眠
以下是本站小編整理的生活類英語美文欣賞： :睡眠，希望對你有所收穫。
Sleep
睡眠
Sleep is part of a person's daily activity cycle. There are several different stages of sleep, andthey too occur in cycles.
睡眠是人每天日常活動循環的一部分。人的睡眠分幾個階段，而這些階段也是循環發生的。
If you are an average sleeper, your sleep cycle is as follows. When you first drift off intoslumber, your eyes will roll about a bit, your temperature will drop slightly, your muscles willrelax, and your breathing well slow and become quite regular. Your brain waves slow down a bittoo, with the alpha rhythm of rather fast waves predominating for the first few minutes. Thisis called stage 1 sleep. For the next half hour or so, as you relax more and more, you will driftdown through stage 2 and stage 3 sleep. The lower your stage of sleep, the slower your brainwaves will be. Then about 40 to 60 minutes after you lose consciousness you will havereached the deepest sleep of all. Your brain waves will show the large slow waves that areknown as the delta rhythm. This is stage 4 sleep.
如果你是一個正常的睡眠者，你的睡眠循環會這樣進行。在你開始昏昏入睡時，你的眼睛會滾動幾下，體溫略有下降，肌肉放鬆，呼吸變得緩慢而有節奏。除了開始幾分鐘比較快的α節奏外，腦電波也稍有減緩。這被稱爲第一階段睡眠。在隨後約半小時內，你進一步放鬆，進入第二和第三階段睡眠。睡眠越深入，腦電波就越緩慢。大約在開始睡眠後的40到60分鐘，你將進入沉睡狀態。這時的腦電波表現爲巨大的緩波，被稱爲δ節奏。這就是第四階段睡眠。
You do not remain at this deep fourth stage all night long, but instead about 80 minutes afteryou fall into slumber, your brain activity level will increase again slightly. The delta rhythm willdisappear, to be replaced by the activity pattern of brain waves. Your eyes will begin to dartaround under your closed eyelids as if you were looking at something occurring in front of period of rapid eye movement lasts for some 8 to 15 minutes and is called REM sleep. Itis during REM sleep period, your body will soon relax again, your breathing will grow slow andregular once more, and you will slip gently back from stage 1 to stage 4 sleep - only to riseonce again to the surface of near consciousness some 80 minutes later.
但你並不是整夜都保持這種沉睡狀態。入睡後約80分鐘左右，你的大腦運動水平會再度略有提高。δ節奏消失，並被腦電波的運動圖形取代。你的眼睛會在閉着的眼瞼下迅速轉動，就好象你在看着眼前發生的什麼事情。這種迅速的眼球運動持續約8-15分鐘，這一階段睡眠被稱之爲快速眼動(REM)睡眠。在REM睡眠階段，你的肢體會很快再度放鬆，呼吸也再次放慢並變得有節奏，你會輕鬆地從第一階段滑入第四階段睡眠——直到大約80分鐘後重新接近清醒狀態。
