| sleep | A natural and healthy, but temporary and periodical, suspension of the functions of the organs of sense, as well as of those of the voluntary and rational soul; that state of the animal in which there is a lessened acuteness of sensory perception, a confusion of ideas, and a loss of mental control, followed by a more or less unconscious state. "A man that waketh of his sleep." "O sleep, thou ape of death." (Shak) Sleep is attended by a relaxation of the muscles, and the absence of voluntary activity for any rational objects or purpose. The pulse is slower, the respiratory movements fewer in number but more profound, and there is less blood in the cerebral vessels. It is susceptible of greater or less intensity or completeness in its control of the powers. <botany> Sleep of plants, a state of plants, usually at night, when their leaflets approach each other, and the flowers close and droop, or are covered by the folded leaves. Synonym: Slumber, repose, rest, nap, doze, drowse. Origin: AS. Slp; akin to OFries. Slp, OS. Slap, D. Slaap, OHG. Slaf, G. Schlaf, Goth. Slps. See Sleep. Source: Websters Dictionary (01 Mar 1998) |
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| sleep apnea | Temporary stoppage of breathing during sleep, often resulting in daytime sleepiness. (12 Dec 1998) |
| sleep apnea syndrome | <syndrome> A disorder characterised by multiple episodes of partial or complete cessation of respiration during sleep. (05 Mar 2000) |
| sleep apnea syndromes | Disorders involving apneic episodes during sleep. They may be due to cessation of diaphragmatic movement, obstruction of upper airway air flow, or a combination of these, and may be associated with hypersomnolence, insomnia, or obesity. (12 Dec 1998) |
| sleep apnoea | <chest medicine> Apnoea caused by upper airway obstruction during sleep, associated with frequent awakening and often with daytime sleepiness. There are three main forms: central sleep apnoea, obstructive sleep apnoea and mixed sleep apnoea. (27 Sep 1997) |
| sleep-at-noon | <botany> A plant (Tragopogon pratensis) which closes its flowers at midday; a kind of goat's beard. Source: Websters Dictionary (01 Mar 1998) |
| sleep deprivation | The condition of being deprived of sleep either under experimental or under unusual real life conditions, as distinguished from being unable to sleep. (12 Dec 1998) |
| sleep disorders | Disturbances of usual sleep patterns or behaviours. (12 Dec 1998) |
| sleep dissociation | <neurology, physiology> A condition that occurs in REM stage sleep. There is no movement of the skeletal muscles in this stage of sleep. See: REM stage sleep. (27 Sep 1997) |
| sleep drunkenness | A half-waking condition in which the faculty of orientation is in abeyance, and under the influence of nightmare-like ideas the person may become actively excited and violent. Synonym: somnolentia. (05 Mar 2000) |
| sleep epilepsy | Incorrect term for narcolepsy. (05 Mar 2000) |
| sleep-induced apnea | Apnea resulting from failure of the respiratory centre to stimulate adequate respiration during sleep; divided into respiratory pause (cessation of air flow for less than 10 seconds) and apneic pause (cessation of air flow greater than 10 seconds). (05 Mar 2000) |
| sleep paralysis | <neurology, physiology> A condition that occurs in REM stage sleep. There is no movement of the skeletal muscles in this stage of sleep. See: REM stage sleep. (27 Sep 1997) |
| sleep phase delay syndrome | <syndrome> A disorder in which the circadian rhythm of sleep and waking falls into a delayed but stable relationship with external time cues of day and night. (05 Mar 2000) |
| sleep, rem | A stage of sleep characterised by rapid movements of the eye and low voltage fast pattern eeg. It is usually associated with dreaming. (12 Dec 1998) |