Chapter_10_Book

Narcolepsy

A disorder characterized by frequent, intense episodes of sleep that last from 5 to 30 minutes and can occur at any time during waking hours.

Cataplexy

A sudden loss of muscle tone leading to collapse of the body without loss of consciousness, often triggered by intense emotions.

Circadian rhythm

A pattern of behavioral, biochemical, or physiological fluctuations that has a 24-hour period.

Orexin (Hypocretin)

A neuropeptide produced in the hypothalamus that is involved in switching between sleep states.

Suprachiasmatic nucleus (SCN)

A small region of the hypothalamus above the optic chiasm that is the location of a circadian clock.

Sleep deprivation

The partial or total prevention of sleep.

Sleep apnea

A sleep disorder in which respiration slows or stops periodically, causing the sleeper to wake.

REM sleep (Rapid-eye-movement sleep)

A stage of sleep characterized by small-amplitude, fast EEG waves, lack of muscle tone, and rapid eye movements.

Delta waves

The slowest type of EEG wave, about 1 per second, characteristic of stage 3 sleep.

Sleep-onset insomnia

Difficulty in falling asleep.

Sleep-maintenance insomnia

Difficulty in staying asleep.

Sleep hygiene

A collection of practices that help ensure better quality sleep, such as maintaining a routine and creating a sleep-inducing environment.

Somnambulism

Also known as sleepwalking, a disorder where individuals walk or perform complex behaviors while asleep without awareness.

Night terrors

A sleep disorder occurring primarily in children, characterized by sudden arousals from sleep with intense fear and autonomic activation.

Hypothalamus

A brain region that contains neurons that regulate sleep-wake cycles.

Atonia

Complete absence of muscle tone, particularly during REM sleep.

Melanopsin

A photopigment found in specialized retinal ganglion cells that are sensitive to light.

Sleep enuresis (bedwetting)

A condition usually occurring in children characterized by involuntary urination during sleep.

Chronotype

The behavioral manifestation of underlying circadian rhythms, often categorized as 'larks' (morning people) or 'owls' (night people).

Sleep paralysis

A temporary inability to move or talk that occurs just before falling asleep or just after waking.

Phase shift

A shift in the activity of a biological rhythm, typically provided by a synchronizing environmental stimulus like light.

Entrainment

The process of synchronizing a biological rhythm to an environmental stimulus.