Reading Comprehension – Informational Passages
Directions: Read the passage. Then answer questions about the passage below. “Wake up!” Do you hear these words often? If so, maybe you are not getting enough sleep. What is sleep? Why do people sleep? How much sleep do you need? All people sleep. All mammals and birds also sleep. Some reptiles, amphibians, and fish sleep too. Scientists understand some of the reasons for sleep. But they do not understand everything about it. There are two kinds of sleep in mammals and birds. One kind of sleep is Rapid Eye Movement sleep, which we call REM sleep. The other kind of sleep is Non–Rapid Eye Movement sleep, which we call NREM or non–REM sleep. The American Academy of Sleep Medicine divides NREM sleep into three stages: N1, N2, and N3 sleep. When people first go to sleep, they are in NREM sleep. The first stage of NREM sleep is N1 sleep. During N1 sleep, people get very drowsy. Some people have muscle twitches during this part of sleep. People are not very conscious of, or aware of, their surroundings during this stage of sleep. Brain monitors identify small, slow, and irregular brain waves during N1 sleep. The second stage of sleep is N2 sleep. People are not at all conscious of their surroundings during N2 sleep. About 45%-55% of total adult sleep is N2 sleep. Brain monitors identify large brain waves with quick bursts of activity during N2 sleep. The third stage of sleep is N3 sleep. It is very deep sleep. Brain monitors identify very slow brain waves during N3 sleep. Therefore, N3 sleep is called slow–wave sleep (SWS.) After N3 sleep, people cycle back to lighter N2 sleep before going into REM sleep. People cycle through the stages of NREM sleep 4 or 5 times each night and enter REM sleep several times during one night. Dreams occur during REM sleep and the eyes move quickly beneath closed eyelids. During REM sleep, people and animals are paralyzed. Scientists...
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