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:
“I’ll view the manners of the town,
Peruse the traders, gaze upon the buildings,
And then return and sleep within mine inn,
For with long travel I am stiff and weary.”
—William Shakespeare (1564–1616)
“Six, or at most seven, hours’ sleep is, for a constancy, as much as you or anybody can want: more is only laziness and dozing, and is, I am persuaded, both unwholesome and stupefying.”
—Philip Dormer Stanhope, 4th Earl Chesterfield (1694–1773)