Sleep
All of us know what sleep is. We know how it feels. The meaning of the word is generally not questioned in ordinary conversation and we do not have to look it up in a dictionary. But no one really knows what happens when we sleep. Once we get beyond the simple level of recognizing sleep as a time of rest in which very little activity occurs, we find that most of the questions involving the nature of sleep remain mostly unanswered. What happens when we sleep? Why do we sleep? If some function of the brain takes place during sleep simply because it is easier to do so, could it also take place in the brain while awake? The questions are endless. But although many questions remain unanswered, scientists have learned a great deal about sleep and will continue to learn more as time goes on. Despite more than a century of scientific study of sleep, including almost three decades of modern intensive research, the function of sleep remains a mystery. There are many theories, but none of them have been proven due to the relatively small amount of data supporting each one. Several of these theories include: restoration and recovery, energy conservation, and ecological hypotheses of foraging and predator avoidance. First, the r
Several well documented sleeping disorders occur when the sleep process does not occur properly. Somnambulism, known as sleepwalking, occurs mostly in young children. A person suffering from sleep walks is usually unaware and does not respond to another's voice. An episode can last between fifteen seconds and thirty minutes ("Sleep and Other Medical"). Narcolepsy is a chronic, lifelong condition of excessive sleepiness and is often accompanied by a sudden urge to sleep. Restless legs syndrome (RLS) is a disorder involving repetitive motions of the legs. It can cause a lack of refreshing sleep, fatigue or problems falling asleep. Sleep apnea is a disorder in which breathing stops for a few seconds or up to two minutes while sleeping. A person may partially awaken when it happens. It may cause morning headaches, insomnia, or hypersomnia. Sleep apnea occurs in both the very young and the old and has been related to sudden infant death syndrome. During REM sleep behavior disorder, individuals appear to act out their dreams. Muscle atonia does not occur and they do not become paralyzed at the onset of REM, like they're supposed to. Finally, insomnia is the inability to fall asleep or to remain asleep restfully throughout the night (Sleep Disorders). The problem of defining sleep was greatly complicated a couple of decades ago when it was discovered that rapid eye movements (REMs) during sleep were a marker of a biological state which was so different from the rest of the sleep cycle that it had to have its own name- REM sleep (Sleep Syllabus). During REM sleep, in addition to rapid eye movements, voluntary muscles are paralyzed (muscle atonia), the nervous system becomes irregular and accelerated, and dreams take place. It is highly suggested that the brain reaches peak activity during this stage of sleep. These events do not happen in any other stage of the sleep cycle ("Sleep"). During REM sleep, the EEG consists of low voltage, mixed frequency pattern, similar to stage one (see below). The background EMG is virtually absent, but small muscle twitches sometimes occur. Generally speaking, sleep is the single most important factor in determining how humans sleep. The newborn infant sleeps sixteen to eighteen hours per day. About fifty percent of a newborn's sleep cycle consists of REM sleep. Three to five-year-olds sleep ten to t
Some common words found in the essay are:
Sleep Syllabus, , Medical Narcolepsy, Sleep Disorders, Sleep REM, EOGs EMGs, Syllabus REM, REM NREM, EEG Third, EMG Changes, rem sleep, sleep cycle, eye movements, sleep syllabus, sleep sleep, nrem sleep, muscle atonia, stage sleep, body temperature, low voltage mixed, voltage mixed, rapid eye movements, consists low voltage, voltage mixed frequency, muscle atonia occur,
Approximate Word count = 1597
Approximate Pages = 6 (250 words per page double spaced)
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