Sleep
Sleep is a naturally recurring state characterized by reduced or absent consciousness, relatively suspended sensory activity, and inactivity of nearly all voluntary muscles. It is distinguished from quiet wakefulness by a decreased ability to react to stimuli, and is more easily reversible than being in hibernation or a coma. Sleep is a heightened anabolic state, accentuating the growth and rejuvenation of the immune, nervous, skeletal and muscular systems. It is observed in all mammals, all birds, and many reptiles, amphibians, and fish.
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Famous quotes containing the word sleep:
“Much sleep is not required by nature, either for our souls or bodies, or for the actions in which they are concerned.”
—Plato (c. 427–347 B.C.)
““What care I for a goose-feather bed,
With the sheet turned down so bravely, O?
For to-night I shall sleep in a cold open field,
Along with the wraggle taggle gipsies, O!””
—Unknown. The Wraggle Taggle Gipsies (l. 33–36)
“Think of the storm roaming the sky uneasily
like a dog looking for a place to sleep in,
listen to it growling.”
—Elizabeth Bishop (1911–1979)