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:
“A speckled cat and a tame hare
Eat at my hearthstone
And sleep there;
And both look up to me alone
For learning and defence
As I look up to Providence.”
—William Butler Yeats (1865–1939)
“Let me have men about me that are fat,
Sleek-headed men, and such as sleep a-nights.
Yon Cassius has a lean and hungry look;
He thinks too much. Such men are dangerous.”
—William Shakespeare (1564–1616)
“Let me have men about me that are fat,
Sleek-headed men and such as sleep a-nights.
Yon Cassius has a lean and hungry look.
He thinks too much. Such men are dangerous.”
—William Shakespeare (1564–1616)