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Published byNicholas Fox Modified over 9 years ago
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EEGs Monitor brain waves Wake people up in the midst of a sleep cycle or dream Eugene Aserinsky – discovered REM sleep › Works with Nathaniel Kleitman William Dement – Father of sleep medicine; World’s first sleep laboratory
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Circadian Rhythms (about a day) › Body rhythms that occur on a 24 hour cycle › Biological clock › Sleep-Awake cycle Ultradian Rhythms › Occur more than once a day › Sleep stages
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Suprachiasmatic Nucleus (SCN) › Cluster of neurons in the hypothalamus › Receives info about day and night cycles from the retina › Depending on cycles detected by eye, it releases neurotransmitters that control body temperature, metabolism, blood pressure, hormone levels, hunger › Works with pineal gland Adenosine › Chemical that triggers sleepiness (high levels = sleepiness) Melatonin › Levels rise as it gets darker (makes us ready for sleep!)
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Pons: Involved in REM sleep › Sends signals to shut off spinal cord Thalamus: helps us tune out sensory signals during sleep
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Bright light at night delays sleep Thinking is sharpest and memory is most accurate when we are at our daily circadian peak After pulling an all nighter you may get a second wind after your normal wake-up time arrives
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Awake/Relaxed › Alpha waves: slow brain waves › Beta waves are alert, waking waves
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Stage 1: › Irregular brain waves › Slowed breathing › Hypnagogic Sensations: Similar to hallucinations Floating weightlessly, falling, etc Stage 2 (after 10-15 minutes): › Sleep spindles – bursts of rapid, rhythmic brain wave activity › Could be awakened without too much difficulty › Spend 50% of the night here Sleep talking usually occurs in these stages!
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Stage 3: › Delta waves: large, slow waves Stage 4: › More delta waves › Deep sleep Hard to waken you during these stages (disoriented) Sleep walking usually occurs here
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Heart rate rises, breathing becomes rapid and irregular, eyes dart around Brainwaves resemble waking brain waves However, brainstem blocks the messages from the motor cortex (although it is active) › Paradoxical Sleep 20% of the night is spent here
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With each 90-minute cycle, stage 4 sleep decreases and the duration of REM sleep increases
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Sleep protects › A species sleep patterns suits its ecological niche Animals with the greatest need to graze and the least ability to hide tend to sleep less Helps us recuperate, restore, and repair brain tissue Helps us restore and rebuild our fading memories Helps creativity May play a role in the growth process (pituitary gland releases growth hormone)
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Insomnia Apnea Nightmares v Night terrors Narcolepsy
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