Stages of Sleep

• What are ultradian rhythms?

  Biological cycles occurring more than once daily
• What type of waves are associated with deep sleep?

  Delta waves
• How can deep sleep be compared to a phone's operation?

  It's like a complete power-off
• What is a variable duration cycle in ultradian rhythms?

  Release of growth hormone
• When does dreaming primarily occur during sleep?

  During REM sleep
• What type of waves are present in Stage 1 NREM sleep?

  Slower, synchronized waves
• What type of waves occur during REM sleep?

  Rapid, irregular waves similar to awake state
• What type of brain waves are present during Stage 1 of sleep?

  Theta waves
• Is it easier to be awakened during Stage 1 or deeper sleep?

  It is easier during Stage 1
• How does NREM sleep progress through its stages?

  NREM sleep becomes progressively deeper
• What are the characteristics of Stage 3 NREM sleep?

  Largest, slowest waves (deep sleep)
• What happens to muscle activity during Stage 1 of sleep?

  It decreases
• What is Stage 1 of sleep also known as?

  Light sleep
• What is the transition period between wakefulness and deeper sleep called?

  Stage 1 of sleep
• What are the stages of sleep and their characteristics?

  1. Awake: Rapid, irregular waves
  2. Stage 1 NREM: Slower, synchronized waves
  3. Stage 2 NREM: Further slowed waves with sleep spindles
  4. Stage 3 NREM: Largest, slowest waves (deep sleep)
  5. REM: Rapid, irregular waves similar to awake state
• How does body temperature change during Stage 1 of sleep?

  It drops slightly
• What are hypnic jerks?

  Sudden muscle twitches during Stage 1
• What are the key characteristics of Stage 1 sleep?

  • Brain waves slow from alpha to theta
  • Body temperature decreases slightly
  • Muscle activity reduces
  • Awareness is present but drifting
  • Duration is the shortest of all sleep stages
• What is the significance of regular heart rate and breathing in deep sleep?

  Indicates a stable physiological state
• What process is consolidated during deep sleep?

  Motor skills
• What type of brain waves are present in Stage 4?

  Consistent and slow delta waves
• Why is Stage 4 sleep essential?

  It is crucial for physical recovery and repair
• What is the third stage of NREM sleep called?

  Deep sleep
• What is Stage 4 of sleep known as?

  Deepest sleep stage
• What does REM stand for in REM Sleep?

  Rapid Eye Movements
• What processes continue in Stage 4 that started in Stage 3?

  Physical recovery, repair, and regeneration processes
• How does deep sleep affect the immune system?

  It strengthens the immune system
• How does Stage 2 NREM sleep prepare the body for deeper stages?

  It deepens sleep and prepares for deeper stages
• What is the role of K-complexes during sleep?

  They help block external stimuli
• What is the purpose of muscle paralysis during REM Sleep?

  To prevent acting out dreams
• How does brain activity during REM Sleep compare to being awake?

  It is very active, similar to being awake
• Why is deep sleep considered restorative?

  It is the deepest part of sleep
• What characterizes deep sleep?

  Very slow delta waves
• How do delta waves relate to deep sleep?

  Delta waves indicate the depth of sleep
• What changes occur in brain waves during sleep?

  They change through distinct stages
• What type of dreams occur during REM Sleep?

  Vivid and memorable dreams
• What is the duration of sleep stages in ultradian rhythms?

  90 minutes
• What role does REM Sleep play in memory consolidation?

  It consolidates memories, especially emotional ones
• What is the frequency range of delta waves?

  0.5-3 Hz
• How does Stage 4 differ from Stage 3?

  Stage 4 features only pure delta waves