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.

Famous quotes containing the word sleep:

“There is sweet music here that softer falls
Than petals from blown roses on the grass,
Or night-dews on still waters between walls
Of shadowy granite, in a gleaming pass;
Music that gentlier on the spirit lies,
Than tired eyelids upon tired eyes;
Music that brings sweet sleep down from the blissful skies.”
—Alfred Tennyson (1809–1892)

“Our treatment of both older people and children reflects the value we place on independence and autonomy. We do our best to make our children independent from birth. We leave them all alone in rooms with the lights out and tell them, “Go to sleep by yourselves.” And the old people we respect most are the ones who will fight for their independence, who would sooner starve to death than ask for help.”
—Margaret Mead (1901–1978)

“smashing the windows of sleep and dream
smashing the windows of history
a whiteness scattering
in hailstones
each a mirror
for man’s eyes.”
—Denise Levertov (b. 1923)