Name the five stages of sleep

What will be an ideal response?

ANSWER:
Stage I sleep is a light sleep and is characterized by theta waves. During this stage, your breathing and heart rate slow down. You may experience sensations such as falling or floating. You can easily awaken from stage I sleep, which typically lasts from 1 to 7 minutes.
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Stage II sleep is characterized by sleep spindles and lasts approximately 20 minutes. Sleep spindles are a pattern of slower theta waves sporadically disrupted by bursts of electrical activity. During stage II sleep, breathing, muscle tension, heart rate, and body temperature continue to decrease. You are clearly asleep and not easily awakened. Research suggests that stage II sleep spindles help us process both simple and complex motor skills that we have learned.
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Stages III and IV sleep are referred to as slow-wave sleep. In stage III sleep, you begin showing delta brain-wave patterns. Delta waves are large, slow brain waves. When a consistent pattern of delta waves emerges, you have entered stage IV sleep. Stage IV sleep is referred to as deep sleep. The body is extremely relaxed. Heart rate, respiration, body temperature, and blood flow to the brain are reduced. Growth hormone is secreted. It is difficult to awaken people from deep sleep. When they are awakened, they may be disoriented or confused. It is believed that during this deep sleep, body maintenance and restoration occur
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After approximately 30–40 minutes of slow-wave sleep, your brain and body start to speed up again. You cycle back through stage II of non-REM sleep and then enter REM (rapid-eye-movement) sleep. REM sleep is a very active stage. Your breathing rate increases, and your heart beats irregularly. Blood flow increases to the genital area and may cause erections in males. However, your muscle tone significantly decreases, leaving the muscles extremely relaxed and essentially paralyzed. REM sleep is intimately connected to dreaming. Although you can dream in some form in all sleep stages, dreams during REM sleep are more easily recalled. More than 80% of people awakened from REM sleep report dreaming.
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