9 Sleep And Biological Rhythms Flashcards
Electro-oculogram (EOG)
Electrical potential from the eyes, recorded by means of electrodes placed on the skin around them; text I movements.
Electromyogram (EMG)
Electrical potential recorded from electrode placed on or in a muscle.
Alpha activity
Smooth electrical activity of 8 to 12 Hz recorded from the brain; generally associated with the state of relaxation.
Beta activity
Irregular electrical activity 13 to 30 Hz recorded from the brain; generally associated with the state of arousal.
Theta activity
EEG activity 3.5 to 7.5 Hz that occurs intermittently during early stages of slow-wave sleep and REM sleep.
Delta activity
Regular, synchronous electrical activity of less than 4 Hz recorded from the brain; occurs during the deepest stages of slow-way sleep.
Slow-wave sleep
Non-REM sleep, characterized by synchronized eyes EEG activity during its deeper stages.
Down state
period of inhibition during a slow oscillation during slow-wave sleep; neurons in the neo cortex are silent and resting.
Up state
Period if excitation during the slow oscillation during slow-wave sleep; neurons in neocortex briefly fire at a high rate.
REM sleep
Period of desynchronized EEG activity during sleep, at which time dreaming, rapid eye movements, and muscular paralysis occurs; also called paradoxical sleep.
Non-REM sleep
All stages of sleep except REM sleep.
Sleep apnea
Cessation of breathing while sleeping.
Narcolepsy
Sleep disorder characterized by periods of irresistible sleep, attacks of cataplexy, sleep paralysis, and hypnagogic hallucinations.
Sleep attack
Irresistible urge to sleep during the day, after which the person awakens feeling refreshed. (Symptom of narcolepsy)
Cataplexy
Complete paralysis that occurs during waking. (Symptom of narcolepsy)
Sleep paralysis
Paralysis occurring just before a person falls asleep. (Symptom of narcolepsy)
Hypnagogic hallucination
Vivid dreams that occur just before person falls asleep; accompanied by sleep paralysis. (Symptom of narcolepsy)
Orexin
Peptide, also known as hypocretin, produced by neurons whose cell bodies are located in the hypothalamus; their destruction causes narcolepsy.
REM sleep behavior disorder
Neurological disorder in which the person does not become paralyzed during REM sleep and thus acts out dreams.
Sleep-related eating disorder
Disorder in which the person leaves his or her bed and seeks out and eats food while sleepwalking, usually without a memory for the episode next day.
Fatal familial insomnia
Fatal inherited disorder characterized by progressive insomnia.
Rebound phenomenon
Increased frequency or intensity of a phenomenon after it has been temporarily suppressed; for example, the increasing rent sleep seen after a period of REM sleep deprivation.
Adenosine
Neuromodulator that is released by neurons engaging in high levels of metabolic activity, may play a primary role in the initiation of sleep.
Locus coeruleous (LC)
Dark-colored group of noradrenergic cell bodies located in the pons near the rostral end of the floor of the fourth ventricle; involved in arousal and vigilance.
Raphe nuclei
Group of nuclei located in the reticular formation of the medulla, pons, and midbrain, situated along the midline; contain serotoninergic neurons.
Histamine
Neurotransmitter synthesized from the amino acid histidine; plays an important role in maintenance of wakefulness and arousal.
Tuberomammillary nucleus (TMN)
Nucleus in the ventral posterior hypothalamus, just rostral to the mammillary bodies; contains histaminergic neurons involved in cortical activation and behavioral arousal.
Ventrolateral preoptic area (vlPOA)
Group of GABAergic neurons in the preoptic area whose activity suppresses alertness and behavioral arousal and promote sleep.
Sublaterodorsal nucleus (SLD)
Region of the dorsal pons, just ventral to the locus coeruleous, that contains REM-ON neurons; part of the REM flip-flop.
Ventrolateral periaqueductal gray matter (vlPAG)
Region of the dorsal midbrain, that contains REM-OFF neurons, part of the REM flip-flop.
Circadian rhythm
Daily rhythmical changing behavior or physiological process.
Zeitgeber
Stimulus (usually the light of dawn) that resets the biological clock that is responsible for circadian rhythms.
Suprachiasmatic nucleus (SEM)
Nucleus that is situated atop the optic chiasm. It contains a biological clock that is responsible for organizing many of the body’s circadian rhythms.
Melanopsin
Photopigment present in ganglion cells in the retina whose actions transmits information to the SCN, the thalamus, and the olivary pretectal nuclei.
Advanced sleep phase syndrome
4-hour advance in rhythms of sleep and temperature cycles, apparently caused by a mutation of a gene (per2) involved in the rhythmicity of neurons of the SCN.
Delayed sleep phase syndrome
4-hour delay and rhythms of sleep in temperature cycles, possibly caused by a mutation of a gene (per3) involved in the rhythmicity of neurons of the SCN.
Pineal gland
Gland attached to the dorsal tectum; produces melatonin and plays a role in circadian and seasonal rhythms.
Melatonin
Hormone secreted during the night of the pineal body; plays a role in circadian and seasonal rhythms.
