Sleep/Wake Cycle & Circadian Rhythm

Consciousness

Awareness of self and environment.

Circadian Rhythm

Body's natural 24-hour sleep clock

NREM Stage 1

falling asleep, easily awakened transition.

Hypnagogic Sensations

Jet Lag

Time zone travel disrupts clock.

Shift Work

Working non-traditional, irregular hours.

NREM Stage 2

Light sleep with brain waves.

Sleep spindles

short bursts of brain activity

K-complexes

sudden, sharp waveforms

NREM Stage 3

Deepest, most restorative sleep stage

Restoration of resources

Sleep restores the body's resources.

REM (Rapid Eye Movement) Sleep

Deep sleep where dreams happen

Activation-Synthesis (Dreams)

Brain signals body to rest

Consolidation Theory (Dreams)

Dreams process and organize memories.

Insomnia

unable to fall asleep easily

Narcolepsy

Sudden, uncontrollable sleep attacks

Sleep Apnea

Breathing stops repeatedly during sleep.

REM Sleep Behavior Disorder

Acting out dreams while asleep.

REM Rebound

Increase time in REM after REM deprivation

Somnambulism

Sleep walking

Catalplexy

Muscle Weakness