An overview of the four stages of sleep and dreaming

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Print Stages of Sleep Since the early 20th century, human sleep has been described as a succession of five recurring stages: Rapid eye movement REM sleep is marked by extensive physiological changes, such as accelerated respiration, increased brain activity, eye movement, and muscle relaxation.

People dream during REM sleep, perhaps as a result of excited brain activity and the paralysis of major voluntary muscles. Sleep quality changes with transition from one sleep stage to another.

Although the signals for transition between the five or six stages of sleep are mysterious, it is important to remember that these stages are, in fact, discretely independent of one another.

Each transition is marked by subtle changes in bodily function and each is part of a predictable cycle whose intervals are observable. Sleep stages are monitored and examined clinically with polysomnographywhich provides data regarding electrical and muscular states during sleep.

Waking The waking stage is referred to as relaxed wakefulness, because this is the stage in which the body prepares for sleep. All people fall asleep with tense muscles, their eyes moving erratically.

Then, normally, as a person becomes sleepier, the body begins to slow down.

Stages of Sleep. Since the early 20th century, human sleep has been described as a succession of five recurring stages: four non-REM stages and the REM stage.(A sixth stage—relaxed wakefulness, the phase during which a person falls asleep—is sometimes included). An Overview of the Four Stages of Sleep and Dreaming PAGES 2. WORDS View Full Essay. More essays like this: stages of dreaming, rapid eye movement, stages of sleep. Not sure what I'd do without @Kibin - Alfredo Alvarez, student @ Miami University. Exactly what I needed. Stages of Sleep. Since the early 20th century, human sleep has been described as a succession of five recurring stages: four non-REM stages and the REM stage.(A sixth stage—relaxed wakefulness, the phase during which a person falls asleep—is sometimes included).

Muscles begin to relax, and eye movement slows to a roll. Stage 1 Sleep Stage 1 sleep, or drowsiness, is often described as first in the sequence, especially in models where waking is not included. Polysomnography shows a 50 percent reduction in activity between wakefulness and stage 1 sleep.

The eyes are closed during Stage 1 sleep, but if aroused from it, a person may feel as if he or she has not slept. Stage 1 may last for five to 10 minutes.

Stage 2 Sleep Stage 2 is a period of light sleep during which polysomnographic readings show intermittent peaks and valleys, or positive and negative waves. These waves indicate spontaneous periods of muscle tone mixed with periods of muscle relaxation.

Muscle tone of this kind can be seen in other stages of sleep as a reaction to auditory stimuli. The heart rate slows, and body temperature decreases. At this point, the body prepares to enter deep sleep. These stages are known as slow-wave, or delta, sleep.

During slow-wave sleep, especially during Stage 4, the electromyogram records slow waves of high amplitude, indicating a pattern of deep sleep and rhythmic continuity. Surprisingly, however, Stages 2 and 3 repeat backwards before REM sleep is attained.

So, a normal sleep cycle has this pattern: Usually, REM sleep occurs 90 minutes after sleep onset.

However, polysomnograms show wave patterns in REM to be similar to Stage 1 sleep. In normal sleep in people without disorders of sleep-wake patterns or REM behavior disorderheart rate and respiration speed up and become erratic, while the face, fingers, and legs may twitch.

Intense dreaming occurs during REM sleep as a result of heightened cerebral activity, but paralysis occurs simultaneously in the major voluntary muscle groups, including the submental muscles muscles of the chin and neck.

Because REM is a mixture of encephalic brain states of excitement and muscular immobility, it is sometimes called paradoxical sleep. It is generally thought that REM-associated muscle paralysis is meant to keep the body from acting out the dreams that occur during this intensely cerebral stage.

The first period of REM typically lasts 10 minutes, with each recurring REM stage lengthening, and the final one lasting an hour. Sleep Cycle The five stages of sleep, including their repetition, occur cyclically.

The first cycle, which ends after the completion of the first REM stage, usually lasts for minutes. Each subsequent cycle lasts longer, as its respective REM stage extends.

Generally, sleep disorders affect the quality, duration, and onset of sleep. Sleep deprivation, frequently changing sleep schedule, stress, and environment all affect the progression of the sleep cycle.

Rapid eye movement latency the time it takes a person to achieve REM sleep may be affected by a sleep disorder like narcolepsy. Psychological conditions like depression shorten the duration of rapid eye movement. Also, treatment for psychiatric conditions often affects sleep, typically inducing a change in sleep habits.

For example, antidepressants like Prozac may cause trouble sleeping and insomnia and can inhibit REM sleep stages. Of course, infants require the greatest amount of sleep. As parents know, total sleep time typically becomes shorter during childhood and may become longer again in adolescence.For children and adults, sleepwalking is usually a sign of lack of sleep, intense emotional problems, stress, or benjaminpohle.com these conditions resolve, sleepwalking incidences disappear.

Since the early twentieth century, human sleep has been described as a succession of recurring stages.

There are five stages of sleep, including four non-REM stages, and Rapid eye movement (REM) sleep. A sixth phase, waking, is often included. When adults first fall asleep, we pass through a couple of light sleep stages, and then plunge into a bout of deep sleep.

Afterwards, we switch into REM, or "rapid eye movement" sleep, a sleep stage famous for its association with dreaming, and the loss of muscle tone.

Mar 31,  · To Sleep, Perchance to Dream - Crash Course Psychology #9 Four Stages of Sleep Sleep basics: Wave form and sleep stages - Duration: . Yahoo Lifestyle is your source for style, beauty, and wellness, including health, inspiring stories, and the latest fashion trends.

Sleep researchers divide sleep into five stages—stages 1, 2, 3, and REM—but to keep things simple, Fitbit groups like sleep stages together. In the app, your sleep will fall into three stages: light, deep, and REM.

Here’s what each of those mean. Stage 1: “This is the sleep that’s a little.