Sleep and Waking

Flashcards summarizing key vocabulary and concepts related to sleep and waking.

Circadian Rhythm

A repeating cycle of about 24 hours that influences various biological processes.

Sleep Deprivation

A condition resulting from inadequate sleep which can lead to significant health issues.

Hypnopompic Hallucinations

REM-type dreams that intrude into the waking state upon awakening.

Cataplexy

A sudden loss of muscle tone that occurs in awake individuals, often triggered by strong emotions.

Sleep Apnea

A breathing-related sleep disorder characterized by pauses in breathing or shallow breathing during sleep.

Melatonin

A hormone secreted by the pineal gland that helps regulate sleep-wake cycles.

Sleepwalking (Somnambulism)

A condition where individuals walk or perform other actions while in a state of sleep.

REM Sleep Behavior Disorder

A sleep disorder where normal REM paralysis is absent, allowing individuals to act out their dreams.

Adenosine

A neurotransmitter that accumulates during wakefulness and promotes sleep.

Insomnia

A sleep disorder characterized by difficulty in initiating or maintaining sleep.

Sleep Terrors

Episodes of fear during sleep that occur in the early part of the night, distinct from nightmares.

Zeitgeber

An external cue for setting biological rhythms, such as light.

NREM Sleep

Non-rapid eye movement sleep, a phase of sleep characterized by slow brain waves and less bodily activity.

Chronotype

An individual's natural inclination to sleep at certain times, such as 'larks' (morning types) and 'owls' (night types).

Suprachiasmatic Nucleus (SCN)

A brain structure that serves as the body's master clock, regulating circadian rhythms.

Ultradian Rhythm

A biological rhythm occurring more than once in a 24-hour cycle, such as the cycle of sleep stages.

Dream

Thoughts, images, sensations, and emotions experienced during sleep.

Nightmare

A REM dream that has disturbing content, typically remembered the next day.

Shift Maladaptation Syndrome

A condition resulting from sleep disruptions due to working shifts inconsistent with a person's circadian rhythms.

Restless Legs Syndrome (RLS)

A disorder causing an irresistible urge to move the legs, often accompanied by unpleasant sensations.

Free-Running Circadian Rhythm

A circadian rhythm that is not synchronized to environmental time cues.

Entrapment

The process of resetting the internal biological clocks to the 24-hour cycle of the earth's rotation.