7 - Sleep Flashcards
What did Edison believe about sleep?
An acquired habit and not that important
Do sleep patterns vary ?
Yes, wide variation amongst individuals.
We get more sleep when we can
What are the stages of sleep?
- Relaxed Wakefulness (alpha waves)
- Stage N1 (theta waves) body temp drops. Around 5 minutes, easily woken.
- Stage N2; eyes still and HR slow, lasts 10-25 minutes.
- Stage N3/N4; slow delta waves. breathing regular, less responsive
- Dreaming/REM Sleep; brain as active as during wakefulness, little body movement.
Describe Stage N2 of sleep
Electrical activity of brain is irregular, slow waves mixed with bursts of activity.
Includes; sleep spindles and k-complex
Eyes are still and HR and breathing slow.
Around 10-25 minutes, around half the night
Describe Stage N3/N4 (Deep Sleep) of sleep
large slow delta waves.
Breathing regular and BP false with pulse.
Brain less responsive to external stimuli.
Time for the body to repair and renew (pituitary gland releases GH and immune system activated)
Describe the Dreaming/REM stage of sleep
Brain is as active as during wakefulness.
Body temp increases, BP increases and Hr and breathing speed up. SNS twice as active.
Little body movement.
Restorative for the mind (facilitates learning and memory)
Around how many cycles of sleep are there a night?
5 cycles
What can affect sleep?
Environmental factors
Anticipate difficult periods
Reduced metabolism, energy saving
Avoid risks (predator)
List the things that benefit with good sleep
Hormonal Function Immune Function Mental Health Vigilance Tasks "Cleaning" the brain (Alzheimers) Emotional Balance
Explain how sleep improves hormonal function
When sleep is restricted to 4 hours a night for 5 days, subjects appear pre-diabetic with insulin regulation all over the place.
Explain how sleep improves immune function
Subjects given Hep vaccination, immune response meant to build slowly.
One night of sleep deprivation (after injection), and show same initial pattern for 2 weeks then diverge.
Explain how sleep improves mental health
Depression and sleep apnea commonly co-exist, which way does the causation line draw?
Explain how sleep improves cleaning the brain
Beta amyloid is a plaque that builds up in the brain and is linked to Alzheimer’s.
At night the cells shrink and the brain clears the beta amyloid plaque
Explain how sleep improves emotional balance
Recall for categories of emotional images is poor after sleep deprivation for positive and neutral images, but negative images are not affected.
