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
A person may partially awaken when it happens. When it gets dark, the cells in the retina of the eye pass a message to a cluster of nerve cells called the suprachiasmatic nucleus (SNA) which is located in the hypothalamus in the center of the brain. During stage one, REMs are absent but slow, rolling eye movements appear and the EEG consists mostly of low voltage, mixed frequency activity. Most adults need between seven and eight hours of sleep per night. Sleep loss often mimics some of the effects of aging, such as memory impairment, diabetes, and hypertension (Sleep Syllabus). NREM and REM sleep alternate throughout the night. The major differences among stages one through four of NREM sleep are in their EEG patterns. 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). These events do not happen in any other stage of the sleep cycle ("Sleep"). In stage four, delta waves dominate the EEG graphs (Sleep Syllabus). estoration and recovery theory simply states that sleep serves to renew all the damage or depletion done to the body during wakefulness. It is theorized that the eye motions correspond to what and where a person is looking during a dream. Generally, three measures have been used to define sleep and the different stages. Growth hormones are also released in the brain during REM sleep (Sleep Disorders). Electrical charges in the brain are measured by an EEG.
Common topics in this essay:
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,
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Acceptance Essays
