| 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 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 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 spindle | The electroencephalographic record of 14-per-second bursts of wave frequency seen on EEG examination. (05 Mar 2000) |
| sleep stages | Periods of sleep manifested by changes in eeg activity and certain behavioural correlates; includes stage 1: sleep onset, drowsy sleep; stage 2: light sleep; stages 3 and 4: delta sleep, light sleep, deep sleep, telencephalic sleep. (12 Dec 1998) |
| sleep terror | A disorder allied to nightmare, occurring in children, in which the child awakes screaming with fright, the distress persisting for a time during a state of saemiconsciousness. Synonym: pavor nocturnus, sleep terror. (05 Mar 2000) |
| rapid eye movement sleep | REM sleep, that state of deep sleep in which rapid eye movements, alert EEG pattern, and dreaming occur; several central and autonomic functions are distinctive during this state. (05 Mar 2000) |
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| paradoxical sleep | A deep sleep, with a brain wave pattern more like that of waking states than of other states of sleep, which occurs during rapid eye movement sleep. (05 Mar 2000) |
| paroxysmal sleep | <neurology> A disorder of sleep associated with excessive daytime sleepiness, involuntary daytime sleep episodes, disturbed nocturnal sleep and cataplexy. Narcolepsy affects over 100,000 people in the United States and appears to have a genetic basis. Symptoms usually begin in the patients twenties. Treatment often includes the use of amphetamines and-or tricyclic antidepressants. (27 Sep 1997) |
| REM stage sleep | <physiology> A stage of deep sleep that is accompanied by rapid eye movement and muscle paralysis. Vivid dreams can be recalled in over 80% of patients who awake from REM stage sleep. (27 Sep 1997) |
| central sleep apnoea | <neurology> A form of sleep apnoea which from the lack of neurologic stimulation to breathe. (12 Jan 1998) |
| mixed sleep apnoea | <chest medicine> A form of sleep apnoea where there is exists a combination of obstructive and central sleep apnoea syndromes. (13 Nov 1997) |
| winter sleep | The dormant state in which some animal species pass the winter. It is characterised by narcosis and by sharp reduction in body temperature and metabolic activity and by a depression of vital signs. It is a natural physiological process in many warm-blooded animals. (12 Dec 1998) |
| multiple sleep latency test | A test of the propensity to fall asleep, done by performing polysomnography during multiple brief opportunities to sleep. (05 Mar 2000) |
| crescendo sleep | Normal sleep, marked by a gradual increase in movements of the sleeper during the course of the night. (05 Mar 2000) |
| hypnotic sleep | <procedure> A state of heightened awareness and focused concentration that can be used to manipulate the perception of pain. (16 Dec 1997) |
| delta sleep-inducing peptide | <chemical> A nonapeptide that is found in neurons, peripheral organs, and plasma. This neuropeptide induces mainly delta sleep in mammals. In addition to sleep, the peptide has been observed to affect electrophysiological activity, neurotransmitter levels in the brain, circadian and locomotor patterns, hormonal levels, psychological performance, and the activity of neuropharmacological drugs including their withdrawal. Chemical name: Delta sleep-inducing peptide (12 Dec 1998) |
| obstructive sleep apnoea | A form of sleep apnoea which occurs as the result of a physical occlusion of the oropharyngeal airway during sleep. (27 Sep 1997) |
| electric sleep | A condition of convulsions and unconsciousness induced by the passage of an electric current through the brain. (05 Mar 2000) |
| electrotherapeutic sleep therapy | Treatment by inducing sleep by means of nonconvulsive electric stimulation of the brain. (05 Mar 2000) |
| twilight sleep | Formerly a method of producing sleep for delivery by a combination of morphine and scopolamine. (05 Mar 2000) |