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:
“Although sleep pressed upon my closing eyelids, and the moon, on her horses, blushed in the middle of the sky, nevertheless I could not leave off watching your play; there was too much fire in your two voices.”
—Propertius Sextus (c. 50–16 B.C.)
“In France a woman will not go to sleep until she has talked over affairs of state with her lover or her husband.”
—Jules Mazarin (1602–1661)