Sleep, What Is It? Essay

This essay has a total of 1011 words and 8 pages.

Sleep, What Is It?

When you lay down to bed at night, close your eyes, and loose conciseness, you

fall asleep. Sleep is an everyday event, every human, every animal does it on a routine

basis. There are many questions concerning sleep. This paper will try to answer three of

them. Why do we sleep, at what routine do we sleep, and what happens to us when we


There are several theories as to why we sleep. Some believe it's a "time out" to

recuperate, remove wastes from muscles, repair cells or recover abilities lost during the

day. However wastes are removed without sleep with just a couple of minutes of rest.

People who don't sleep for 48 hours don't need 16 hours to "catch up" all they need is

one good nights sleep. Some believe sleep conserves energy, once it provided safety from

predators in a secluded space. However we lose consciousness which would make us

vulnerable to attacks from predators. Or maybe it serves the brain because only

organisms with integrated bundles of central nervous tissue sleep. There are many

theories as to why we sleep but no one really seems to know.

People can go several days without sleep and still perform normally. However any

longer can cause irritability, hallucinations, or delusions. In animals sleep depravation

leads to death, it may also hold true for people as well. In one case a man at age 52

started losing sleep. He fell deeper and deeper into an exhausted stumper or lethargic state, always feeling

tired but unable to sleep. He eventually developed a lung infection and died. An autopsy

showed he had lost almost all of the large neurons in two areas of the thalamus. This

suggests that sleep is caused and controlled by the thalamus.

Most people sleep at night, so does this mean that our sleep cycle is dependent on

night and day? It doesn't seem so. There are people who sleep during the day and studies

have shown that people run on their own sleep cycles. Volunteers put in isolation(they

didn't know what time it was) went to sleep on the average 49 minutes later every cycle.

So in about 11 or 12 days one would go to sleep in the morning. Whenever we change

our clocks(daylight savings time) our bodies eventually readjust to the time rather than

how light or dark it is outside. People who live in the extreme north or south have

darkness for six month at a time, yet they go to bed on a regular cycle. Sometimes after a

hard day someone might go to bed early. So it does not seam that human sleep is dictated

by night or day but by our own personal cycles. There are exceptions however, like when

one feels tired in the morning, or awake when you go to bed, but generally we have our

own unique sleep cycles.

Physically when we sleep wastes are removed from our muscles, we digest food,

and damaged cells are repaired. Also our heart rate lowers, we breath slower and more

deeply, and our metabolism falls. Basically when we sleep, physically we slow down,

repair ourselves, and get ready for the next day.

Dreaming can be divided into two main blocks, daydreams and sleep dreams.

Daydreams occurs during wakefulness. Daydreams usually are about current problems or

challenges, especially emotional problems like relationships. Daydreams can be about

past events or to indulge in fantasies. But generally daydreams are clear and easy to

understand. Daydreams occur over a 90 minute cycle and usually when you're alone.

Daydreaming is beneficial, it can provide entertainment when bored and exercise human

creativity. Sleep dreaming occurs during sleep. When most people dream they don't have
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