Sac 1 unit 4

• Sleep is a physiological construct - a naturally occurring state of consciousness
• NREM


  Non-Rapid Eye Movement sleep
• REM


  Rapid Eye Movement sleep
• NREM sleep is characterized by the absence of rapid eye movement
• REM sleep is characterized by rapid eye movements and vivid dreaming
• NREM sleep


  • Different stages with varying degrees of depth
  • Physiological restoration
• REM sleep


  • Increased brain activity
  • Vivid dreaming
  • Temporary paralysis
• Measuring sleep


  1. Understand sleep patterns

  2. Diagnose sleep disorders
• EEG


  Electroencephalography - measures brain waves
• EMG


  Electromyography - measures muscle tone during REM atonia
• EOG


  Electrooculography - measures eye movements
• Sleep diaries provide subjective information about sleep
• Video monitoring helps diagnose sleep disorders
• Circadian rhythms


  Regulated sleep-wake cycle
• Ultradian rhythms contribute to sleep regulation
• The superchiasmatic nucleus (SCN) is the body's central pacemaker
• Daylight influences the SCN by stimulating light-sensitive neurons
• Melatonin


  Produced by the pineal gland, helps signal the body to prepare for sleep
• Melatonin levels rise in the evening and decline in the morning
• High levels of light can decrease melatonin production
• Low levels of light cause melatonin to be used, creating feelings of drowsiness
• Changes in sleep duration and patterns

  • Babies
  • Infants
  • Children
  • Adolescents
  • Adults
  • Elderly
• Babies require about 16 hours of sleep
• Infants require about 12-13 hours of sleep
• Children require about 11-12 hours of sleep
• Adolescents require about 9-10 hours of sleep
• Adults require about 7-9 hours of sleep
• Elderly individuals require about 6-7 hours of sleep
• Sleep patterns change due to various factors including brain development and social factors
• Sleep deprivation can lead to mood disturbances and impaired functioning
• Partial sleep deprivation is less sleep in 24 hours than required
• Full sleep deprivation is no sleep in 24 hours or more
• Effects of sleep deprivation

  • Affective effects
  • Cognitive effects
  • Behavioural effects
• Delayed Sleep Phase Syndrome (DSPS) is a prevalent sleep disorder
• Advanced Sleep Phase Disorder (ASPD) occurs due to an earlier sleep cycle
• Shift work can disrupt circadian rhythms
• Bright light therapy


  Aims to reset the biological clock regulating sleep-wake cycles
• Good sleep hygiene includes having a regular bedtime and avoiding screens before bed
• Zeitgebers are external cues that influence circadian rhythms
• Daylight is a primary zeitgeber