Essay about importance of sleep

984 Words Oct 1st, 2013 4 Pages
Sleep is a physical and mental resting state in which a person becomes relatively inactive and unaware of the environment. In essence, sleep is a partial detachment from the world, where most external stimuli are blocked from the senses.

Normal sleep is characterized by a general decrease in body temperature, blood pressure, breathing rate, and most other bodily functions. In contrast, the human brain never decreases inactivity. Studies have shown that the brain is as active during sleep as it is when awake. Throughout an eight-hour sleep cycle, a normal adult alternates between two very different states, non-REM and REM (Rapid Eye Movement) sleep.
Sleep is characterized by two distinct states, non-REM sleep and REM sleep. Non-REM and
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So too, humans have a natural cycle of approximately the length of one day.

Small structures in the brain called suprachiasmatic nuclei (SCN) coordinate circadian rhythms. The SCN, in turn, is very sensitive to the presence or absence of light. This may explain why daytime sleep has been found to be less restful than nighttime sleep.

Sleep and wakefulness alternate, usually between night and day, respectively. For most people, sleepy peaks occur every 12 hours, at night, and around mid-afternoon. Through a complex process of hormonal and neurological changes, daylight naturally triggers periods of wakefulness. Studies have shown, however, that the absence of light does not disable our biological clocks.

The longer a person stays awake, the more sleep he or she requires; thus, the need to sleep accumulates throughout the time of wakefulness. This regulation is called homeostatic because it allows the body to reverse the effects of sleepiness by sleeping.

Normal peaks of alertness occur during daylight hours. The mid-afternoon dip, called a postprandial dip (after lunch), is caused by a natural decrease in body temperature. When our body temperature begins to drop, we are sleepier than when it begins to rise.
Sleep is a necessary and vital biological function. It is essential to a person's physical and emotional well being. Studies have shown that without enough sleep, a person's ability to perform even simple tasks declines dramatically.


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