Flashcards in sleep REVISE Deck (37)
when do babies get a sleep wake cycle of 24 hours?
by around 6 months
REM sleep takes up around 50% of sleep duration
what is the role of the SCN?
controls the timing of the sleep wake cycle and co-ordinates it with other circadian rhythms
as well as other functions like attention and body temperature
internal body clock
what is the role of melatonin in sleep?
hormone released by the pineal gland into the bloodstream at around 9pm as instructed by the SCN (using environmental cue of light detected by the retino-hypothalamic tract)
induces sleep by regulating the sleep-wake cycle
secretion stops around 7.30am
where is the SCN located?
in the anterior hypothalamus
what time are we in our deepest sleep?
what is the role of cerebral spinal fluid in sleep? as shown by mice?
it is pumped around the brain (10x faster than when awake as brain cells shrinkwhen asleep so space between them 60% greater) and flushes out waste products e.g toxic proteins whose build up can lead to dementia
issue with generalisation of brain research on mice to humans?
what happens in a mouse brain might be very different to what happens in more complex human brain as
"sleep in humans has evolved far more sophisticated functions for our cortex than that for the mouse"
might be many other functions of sleep in the human brain due to it's superior complexity
what are the systems benefits of sleep to the body?
restoration of vigilance, learning and cognition
memory consolidation and integration
occurs in REM sleep
cellular level benefits of sleep?
restoration of energy, supplies, cellular homeostasis and extracellular space
lack of sleep reduces number of infection fighting antibodies and so is less effective at fighting infectious disases
lack of sleep inhibits wound healing process
occurs in NREM sleep
role of the hypothalamus?
contains the SCN acting as an internal pacemaker
contains the VLPO which inhibits activity in areas that maintain wakefulness
role of the limbic system?
drive and emotional reactivity
what is the role of the amygdala?
processing emotions and forms part of the limbic system
role of frontal lobe?
assess, plan, inhibit, act (control pannel)
contains Broca's area in the left frontal gyrus
responsible for language production
role of parietal lobe?
sensory actions and visual information
role of temporal lobe?
language and memories
contains Wernicke's area in left temporal gyrus
responsible for comprehension of language
role of occipital lobe?
what is the cycle of human sleep
90 mins of alternating NREM and REM (25%) sleep
what are the 3rd and 4th stages of sleep known as and what occurs in them?
muscles relax and increased blood flow to them
body repairs and energy stores replenished
signals of deprived REM sleep?
perceptual distortions, mood impairment, impaired concentration
which lobe is inactive during sleep and why?
the frontal lobe as no decisions need to be made
which area is active during sleep and why?
the temporal area as it deals with memory
what percentage of the average persons dreams are nightmares?
names of some sleep disorders
limb movement disorder
psychological causes of sleep problems
other mood disorders:
depression - difficulty waking or getting to sleep and tired in the day
anxiety - frequent waking as alert and awake very early
stress: e.g fears in night
anxiety about sleep
health, habits and environmental causes of sleep problems
health : pain / medication
drinks : caffeine, alcohol, need to go to toilet
poor sleep routine: sleeping in day, shift work, surroundings e.g noisy
prevalence of insomnia
1 in 9 have nightly insomnia (1999) (Ancoli-Israel and Roth)
strategies for better sleep?
put the day to rest
block thoughts - counting backwards
relaxation - breathing and imagery
challenge negative thinking
don't watch the clock
what is the associated between sleep disorders and mood/mental health disorders?
e.g anxiety may cause sleep disorder as alert at night but lack of sleep may cause anxiety
what is primary insomnia?
difficulty initiating or maintaining sleep or nonrestorative sleep for at least 1 month (4 nights a week)