week 5

Hypothalamus

controls onset of sleep

Suprachiasmatic nucleus (SCN)

• clusters of thousands of cells that receive information about light exposure directly from the eyes and control behavioral rhythm

Hippocampus

• memory region active during dreaming 

amygdala

emotion center active during dreaming

Thalamus

• prevents sensory signals from reaching the cortex (active during REM)

Basal forebrain

• romotes sleep and wakefulness

  • Releases adenosine to support sleep drive system

Brain stem

 base of brain, including the midbrain, pons, and medulla, communicate with the hypothalamus

Pons and Medulla

• help to initiate REM sleep and send signals to relax the muscles involved in body posture and limb movements, so we don’t act out our dreams

Pineal Gland

• Secrets melatonin, which is involved in regulation of circadian rhythms

Rapid eye movement (REM)

• Active sleep

• Brain wave activity is similar to wakefulness 

• Complete loss of muscle tone 25% of sleep

Non-rapid eye movement (Non-REM)

75% of sleep. tissue growth. quiet sleep

NREM Stage 1

• Duration 5% of total sleep time 

• Transition from wake to sleep

NREM Stage 2

• Duration 40-55% of total sleep time 

• Bridge from light to deep sleep 

•  Body temperature drops and heart rate begins to slow

NREM stage 3

• Duration: 10-20% of total sleep time 

• Cellular repair 

• Muscles relax

• Blood pressure and breathing rate drop

• Deepest sleep occurs

REM

• 20% of total time

• Brain becomes more active 

• Body is relaxed and immobilized 

• Dreaming

• Memory consolidation

Sleep regulators

• Wake time 

• Sunlight exposure 

• Core body temp

• Zeitgebers

C process: circadian rhythm

• Sleep-wake cycle

• Are internally driven cycles that rise and fall during the 24-hour day

• Help you fall asleep at night and wake you up in morning 

Combining c and S processes

• Sleep happens with a coordinated effort between c and s processes 

• Other things can influence this, such as light exposure, body temperature, regular sleep/wake times, and physical activity

Intervention strategies to improve sleep

• Assistive devices/ equipment

• CBTi

• Mindfulness activities 

• Lifestyle intervention