Lecture 11 Sleep Slides

Course Information

  • Course Title: Sleep HS1111

  • Institution: Western X HealthSciences

  • Instructor: Dr. Anushka Ataullahjan

Learning Outcomes

  • Identify the influences on sleep duration and timing, including different sleep chronotypes.

  • List the various factors that affect sleep.

  • Describe the negative effects of sleep deprivation on:

    • Physical health

    • Mental well-being

    • Overall quality of life

Why Do We Sleep?

  • Essential Functions of Sleep:

    • Sleep performs many important functions, but the evolutionary purpose is still unclear.

    • Variations in sleep duration and mechanisms regulating sleep initiation and maintenance are studied, including the roles of neurotransmitters and hormones.

    • Dreaming is also an important aspect of sleep.

Functions of Sleep

  1. Restoration

    • Muscle and tissue repair.

    • Supports overall bodily functions.

  2. Memory Consolidation

    • Influences memory retention.

  3. Emotional Regulation

    • Helps manage stress and irritability.

  4. Brain Function

    • Essential for cognitive processes.

  5. Energy Conservation

    • Facilitates energy management throughout the day.

Circadian Clock

  • Definition: The internal body clock is discovered in the 18th century, regulating biological rhythms.

Experimental Insights

  • Kleitman and Richardson Experiment:

    • Studied influences like sunlight, temperature, and humidity on sleep-wake cycles.

Variations in Circadian Cycle

  • Factors Influencing Variations:

    • Genetics

    • Age

    • Environmental influences

    • Medical conditions

Sleep Chronotypes

  • Types of Chronotypes:

    • Morning Larks

    • Hummingbirds (intermediate)

    • Night Owls

  • Variability is genetically determined.

Genetics and Chronotypes

  • The molecular clock includes networks of timekeeping genes and proteins such as CLOCK/BMAL1, CRY, and PER.

  • Extreme morning larks have familial traits and specific sleeping patterns (falling asleep early, waking up early).

Chronotype Distribution

  • Reference studies on mid-sleep on free days.

Sleep Timing and Life Course

  • Children generally display earlier chronotypes, which shift later during puberty, peaking around age 20.

  • Sleep patterns continue to shift earlier in subsequent decades, influenced by endocrine factors.

Sex Differences in Sleep Timing

  • Females reach maximum lateness at around 19.5 years, males around 21 years.

  • Differences generally equalize around age 50 due to hormonal changes.

Sleep Disorders

  • Disordered Sleep Cycles:

    • Occur when sleep-wake patterns misalign with desired sleep time.

  • Jetlag:

    • Symptoms include insomnia, excessive daytime sleepiness, and impaired function.

    • Treatment involves light exposure and melatonin.

  • Shift Work Disorder:

    • Affecting 10-38% of shift workers, causing insomnia and reduced sleep duration.

    • Treatment typically involves reverting to traditional schedules.

Other Sleep Disorders

  • Delayed Sleep-Wake Phase Disorder

  • Non-24-Hour Sleep-Wake Rhythm Disorder

  • Irregular Sleep-Wake Rhythm Disorder

Circadian Misalignment

  • Linked to negative health outcomes:

    • Higher rates of psychiatric disorders like depression in late chronotypes and shift workers.

    • Long-term effects may include increased risk of dementia and cancer.

Evolutionary Perspective on Chronotypes

  • Potential evolutionary advantages for varied chronotypes include group survival strategies and resource competition.

Stigma Associated with Chronotypes

  • Studies indicate stigmas against night owls regarding laziness and health.

  • 20% of individuals experienced chronotype-based discrimination, more pronounced in women.

Assessing Your Chronotype

  • Reflection questions to understand sleeping patterns and preferences.

Importance of Knowing Your Chronotype

  • Knowing your chronotype aids in scheduling analytical tasks and making decisions effectively.

Optimizing Sleep Schedule

  • Align tasks and commitments with your chronotype for better performance.

Recommended Sleep Duration

  • Adults: 7-9 hours per night, with many not meeting this need.

Influences on Sleep

Environmental Factors

  • Temperature:

    • High temperatures can disrupt REM and deep sleep.

Technology Effects

  • Blue Light Exposure:

    • Interferes with melatonin production, disrupting sleep.

Substance Influence

  • Alcohol:

    • Effects vary based on quantity:

      • Low doses may decrease sleep quality by 9-24%.

      • High doses drastically reduce sleep quality.

  • Caffeine:

    • Also affects sleep quality and duration.

Mental States and Sleep Quality

  • Anxiety and stress can lead to poor sleep quality and reinforce negative emotions.

Restoration and Repair of Sleep

  • Sleep is essential for muscle recovery, cellular repair, and overall health.

Cognition and Decision-Making

  • Sleep impacts cognitive functions including problem-solving and creativity.

Memory Processes

  • Sleep supports memory consolidation, integrating new memories into existing frameworks.

Impacts of Sleep Deprivation

  • Emotional regulation can be heavily impacted, leading to increased risk of mental health issues.

Brain Detoxification During Sleep

  • The glymphatic system clears waste during sleep. Poor sleep increases toxic accumulation linked to diseases like Alzheimer's.

Effects of Daylight Savings Time

  • Research shows a higher rate of spontaneous pregnancy loss associated with spring daylight savings when occurring shortly after embryo transfer.

Long-Term Consequences of Sleep Deprivation

  • Affects physical and mental health, increasing risks for various diseases and disorders.

Enhancing Sleep Quality

Daytime Naps

  • Naps can enhance learning, memory consolidation, and emotional regulation.

Sleep Hygiene Practices

  • Recommend practices to promote healthy sleep:

    • Relaxation techniques

    • Healthy eating

    • Regular exercise

    • Consistent sleep schedule

    • Sleep-conducive environments

Prescription of Sleep

  • Emphasis on prescribing sleep schedules rather than sleeping aids.