Unit 1. Bio Foundations - Pt 6: Conciousness & Sleep

Consciousness

Awareness of internal states and external surroundings; includes both wakefulness and sleep.

State of consciousness

Level of awareness and alertness at any given time.

Circadian rhythm

A 24-hour biological cycle that regulates sleep/wake patterns, body temperature, and hormones.

Jet lag

Disruption of circadian rhythms due to travel across time zones.

Shift work

Disruption of natural circadian rhythm due to working night or rotating shifts.

EEG (Electroencephalogram)

Tool used to measure brain wave patterns associated with different stages of sleep.

NREM sleep

Includes Stages 1–3; associated with slower brain waves and minimal dreaming.

hypnagogic sensations

vivid, dreamlike experiences that occur during the transition between wakefulness and sleep; occur at Stage 1 NREM

Stage 1 (NREM 1)

Light sleep stage; characterized by theta waves and hypnagogic sensations.

Stage 2 (NREM 2)

Characterized by sleep spindles and K complexes; body begins to relax.

Stage 3 (NREM 3)

Deepest sleep stage; dominated by delta waves.

REM sleep

Rapid Eye Movement sleep; vivid dreams occur, brain resembles wakefulness, body is paralyzed.

Paradoxical sleep

Another term for REM sleep—brain is active, body is immobile.

REM rebound

Increased REM sleep after deprivation, suggesting its importance.

Memory consolidation theory

Sleep helps process and organize memories and experiences.

Memory restoration theory

Sleep restores depleted resources (energy, neurotransmitters, etc.) used during the day.

Insomnia

Difficulty falling or staying asleep; most common sleep disorder.

Narcolepsy

Sudden sleep attacks, often into REM sleep; linked to hypocretin (orexin) deficiency.

REM sleep behavior disorder

Acting out dreams during REM due to failure of muscle paralysis.

Sleep apnea

Breathing stops temporarily during sleep; leads to frequent awakenings.

Somnambulism

Sleepwalking during deep NREM sleep; considered a parasomnia.