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Sleep; Circadian Rhythm

The lesson delves into the intricacies of sleep and the circadian rhythm, highlighting the structure of sleep cycles, the sequencing and characteristics of sleep stages, and the impact of these patterns on physical and mental health.
  • Sleep is divided into cycles and stages, with adults typically experiencing 4 to 5 cycles per night, each lasting 90 to 110 minutes.
  • There are four stages of sleep within each cycle, including REM (Rapid Eye Movement) and non-REM stages, with stage sequencing varying across the night.
  • Sleep stages serve various functions, from memory consolidation and mood regulation to immune system regulation and appetite control.
  • The circadian rhythm, an internal clock set to approximately 24 hours, regulates sleep patterns and is influenced by external light and lifestyle factors.
  • Sleep needs and patterns change across the lifespan, with variations in REM and slow-wave sleep observed from infancy to adulthood.
Understanding Sleep Cycles
The Four Stages of Sleep
Sleep Stage Sequencing
The Circadian Rhythm