Sleep

related topics
{disease, patient, cell}
{specie, animal, plant}
{day, year, event}
{theory, work, human}
{rate, high, increase}
{album, band, music}
{company, market, business}
{acid, form, water}
{system, computer, user}
{town, population, incorporate}

Sleep is a naturally recurring state characterized by reduced or lacking consciousness, relatively suspended sensory activity, and inactivity of nearly all voluntary muscles.[1] It is distinguished from quiet wakefulness by a decreased ability to react to stimuli, but it is more easily reversible than hibernation or 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.

The purposes and mechanisms of sleep are only partially clear and are the subject of intense research.[2] Sleep is often thought to help conserve energy,[3][4] but actually decreases metabolism only about 5–10%.[3][4] Hibernating animals need to sleep despite the hypometabolism seen in hibernation, and in fact they must return from hypothermia to euthermy in order to sleep, making sleeping "energetically expensive."[5]

Contents

Full article ▸

related documents
Testosterone
Vitamin D
Epilepsy
Lysergic acid diethylamide
Inflammation
Attention-deficit hyperactivity disorder
Menopause
Drug addiction
Tocopherol
Sudden infant death syndrome
Cerebellum
Hormone
Methadone
Obsessive-compulsive disorder
Electroconvulsive therapy
Acne vulgaris
Omega-3 fatty acid
Methylenedioxymethamphetamine
Syringomyelia
Angiogenesis
Hypertension
Gene therapy
Combined oral contraceptive pill
Reelin
Psoriasis
Coronary artery disease
Modafinil
Morphine
Chemotherapy
Brain