Sleep Stages: NREM and REM

Stages of Sleep

Sleep consists of two main stages: Non-Rapid Eye Movement (NREM) and Rapid Eye Movement (REM) sleep.

NREM Sleep

• Divided into three stages:
  1. Stage 1: Transition from wakefulness to sleep, characterized by slow eye movements and a decrease in body temperature.
  2. Stage 2: Body temperature cools, heart rate slows, and body prepares for deeper sleep.
  3. Stage 3: Deep sleep, also known as slow-wave sleep, where brain waves slow down significantly.

REM Sleep

• Characterized by:
  • Rapid eye movements
  • Increased brain activity, similar to when awake
  • Vivid dreams
  • Paralysis of the muscles to prevent acting out dreams

Sleep Cycles

• A full sleep cycle typically lasts around 90-120 minutes
• Each cycle consists of NREM stages 1-3, followed by REM sleep
• Most people experience 4-6 sleep cycles per night

Functions of Sleep

• Memory Consolidation: Sleep helps process and strengthen memories
• Physical Restoration: Sleep gives the body a chance to repair and regenerate tissues, build bone and muscle, and strengthen the immune system
• Hormone Regulation: Sleep influences the balance of various hormones, including insulin, growth hormone, and hormones that regulate appetite and metabolism
• Emotional Well-being: Sleep helps regulate emotions and reduce stress

Sleep Disorders

• Insomnia: Difficulty initiating or maintaining sleep
• Sleep Apnea: Pauses in breathing during sleep
• Narcolepsy: Excessive daytime sleepiness and sudden attacks of sleep
• Restless Leg Syndrome: Uncomfortable sensations in the legs during sleep

Tips for Improving Sleep

• Establish a Consistent Sleep Schedule
• Create a Sleep-Conducive Environment (dark, quiet, cool)
• Avoid Stimulating Activities Before Bedtime
• Avoid Caffeine and Electronics Before Bedtime
• Exercise Regularly, But Not Before Bedtime

Stages of Sleep

• NREM (Non-Rapid Eye Movement) sleep is divided into three stages:
• Stage 1: transition from wakefulness to sleep, slow eye movements, and decreased body temperature
• Stage 2: body temperature cools, heart rate slows, and body prepares for deeper sleep
• Stage 3: deep sleep (slow-wave sleep), brain waves slow down significantly
• REM (Rapid Eye Movement) sleep is characterized by:
  • Rapid eye movements
  • Increased brain activity (similar to when awake)
  • Vivid dreams
  • Paralysis of muscles to prevent acting out dreams

Sleep Cycles

• A full sleep cycle typically lasts 90-120 minutes
• Each cycle consists of NREM stages 1-3, followed by REM sleep
• Most people experience 4-6 sleep cycles per night

Functions of Sleep

• Memory Consolidation: process and strengthen memories
• Physical Restoration: repair and regenerate tissues, build bone and muscle, and strengthen immune system
• Hormone Regulation: influence balance of various hormones (insulin, growth hormone, appetite and metabolism hormones)
• Emotional Well-being: regulate emotions and reduce stress

Sleep Disorders

• Insomnia: difficulty initiating or maintaining sleep
• Sleep Apnea: pauses in breathing during sleep
• Narcolepsy: excessive daytime sleepiness and sudden attacks of sleep
• Restless Leg Syndrome: uncomfortable sensations in legs during sleep

Tips for Improving Sleep

• Establish a Consistent Sleep Schedule
• Create a Sleep-Conducive Environment (dark, quiet, cool)
• Avoid Stimulating Activities Before Bedtime
• Avoid Caffeine and Electronics Before Bedtime
• Exercise Regularly, But Not Before Bedtime