Ch.9 Flashcards
what is circadian rhythm
anything on a daily cycle of change such as timing of our sleep and wake cycles
what does the suprachiasmatic nucleus (SCN) do
receives stimulation from light via the retina
where is the SCN found
hypothalamus
what is a seitgeber
german for “time giver”, light is an example as it tells us when its day and night
where does the penal gland get its info from and what doe sit produce
-gets retinal input
-produces melatonin
what can lead to disruption of the sleep cycle
shift work, jet lag, trouble sleeping at night
what negative health effects occur as a result of a messed up sleep cycle
obesity, diabetes, increased risk of accidents
what is sleep
reversible state characterized by minimal movement, a relaxed posture, and diminished attention directed to the environment
what is polysomnography
physiological recording of observations of sleep
what does an EEG measure when sleeping
brain activity
what does and EOG measure during sleep
eye movements
what does and EMG measure during sleep
muscle tension
when do we see beta waves and what do they measure at
-when we are awake
-13-30 Hz
when do we see alpha waves and what do they measure at
-when we are sleepy
-8-12Hz
when do we see theta waves and what do they measure at
-during stage one of sleep
-3-7Hz
how much of sleep is spent in stage 1
4-5%
when do we see sleep spindles and K complexes and what do they measure at
-stage 2 sleep
-12-14Hz
how much of sleep is spent in stage 2
45-55%
when do we see delta waves and what do they measure at
-during slow wave sleep
-.5-3Hz
how much sleep is spent in slow wave sleep
16-21%
what happens in REM sleep
-rapid eye movement
-faster waves that resemble waking
how much sleep is spent in REM sleep
20-25%
what is the ascending reticular activating system (ARAS)
-a neural network that sends projections from the brainstem and hypothalamus throughout the forebrain
-involved in wakefulness
-when lesioned in cats they entered a permanent sleep
what is the raphe nuclei
-found in the brainstem
-produces serotonin
what does Acetylcholine contribute to in sleep
sustaining beta waves
what does serotonin contribute to
wake and sleep
what occurs during slow wave sleep
-brain no longer responds to environmental sensory cues
-Cortex and thalamus are in synchrony
-happens locally, different parts are benefiting from slow wave sleep at different points in time
what does the ventrolateral preoptic area (VLPO) do during SWS
-increases activity (unlike most other neurons that decrease)
-activates GABAergic and galaniergic neurons that diminish wakefulness, makes you more deeply asleep
what is the role of the TuberoMammillary Nucleus (TMN)
has to do with circadian rhythm and immune functions
when does atonia occur during sleep and what is it
REM sleep
relaxed muscles
what are pontogeniculooccipital (PGO) spikes
electrical potentials that start in the pons, go to the thalamus, then end in the occipital lobe and are correlated with rapid eye movements
what is the role of the subcoeruleus and what happens when it is damaged
generator of REM, damage leads to less REM sleep
homeostatic theory of sleep
-provides rest and recovery
sleep rebound effect
idea that we make up sleep we miss out on
how much sleep can we make up
30%
wheat can sleep deprivation lead to
-cognitive deficits
-motor performance
-emotional regulation
-hallucinations
adaptive theory of sleep
-sleep helps us when it is not beneficial for us to be awake
-hiding and protecting us from predators
-food is scarce, time to sleep
Memories and sleep
-Hippocampal neurons fire in SWS
-Rehearsal of learned info
-Memory consolidation
Synaptic homeostasis hypothesis
-sleep prunes weaker synapses
-strengthens stronger synapses
-production of synapses decreases during sleep
REM sleep and memories
-Consolidates procedural memories
-Deprivation leads to memory deficits
-After learning difficult tasks we spend increased time in REM
-Processing survival related info
what is sleep debt
difference in amount of sleep you need and amount of sleep you get
sleep efficiency
percentage of time in bed that you are actually asleep
how can sleep affect vaccines
vaccines are less effective when people have interrupted sleep
what’s the role of interleukin 1 and tumor necrosis factor, what are they, and where are they found
-immune system chemicals
-located in sleep-wake-regulatory centers (brainstem, hippocampus, hypothalamus)
-presence of these increases SWS
how does sickness disrupt sleep
-disrupts REM and SWS
-REM prevents shivering and SWS decreases temp which is part of the process for our body to get rid of sickness
-when interleukin 1 and tumor necrosis factor are blocked, SWS decreases
what is insomnia
difficulty falling or staying asleep
what percent of americans experience insomnia nightly? few nights a week?
35%
58%
treatments for insomnia include
-Medications (GABA agonists)
-Cognitive behavioral therapy (CBT)
-Exercise (late afternoon)
-Dim the lights before bed
-Limit caffeine and alcohol
-Bedroom hygiene (temp, light control)
who is most likely to have insomnia
older adults
what is narcolepsy
REM related disorder in which people fall asleep unexpectedly characterized by weak muscles/paralysis (cataplexy), hypnagogic hallucinations and become sleepy during emotional arousal
what is cataplexy
Weak muscles/paralysis, experienced in narcolepsy
what stage of sleep decreases in narcolepsy
SWS
what is orexin
neurotransmitter that keeps us awake
how is orexin impacted in those with narcolepsy
Those with narcolepsy have a genetic condition that keeps them from producing enough orexin to stay awake
treatments for narcolepsy
-antidepressants
-stimulants
-hypnotic drugs
what is sleep apnea
seeping disorder where people wake mid sleep due to lack of oxygen
what is obstructive sleep apnea
due to blockage of airway
what is central sleep apnea
Impaired brain mechanisms controlling breathing during sleep
consequences of sleep apnea
-Little slow wave sleep
-Less REM
-Risk of heart attack, stroke, high blood pressure
-Decrease of cortical gray matter
what is the CPAP machine used for
-treating sleep apnea
-Pressurizes the air so it can get through the throat more easily
what is sleep paralysis
happens while falling asleep or waking up in which a person is aware but unable to move of speak, this is a REM related disorder
treatments for sleep paralysis
Improve sleep hygiene
CBT
Antidepressants
what is REM sleep behavior disorder
-Dreams are acted out with talking, kicking, jumping, etc
-More often seen in men/older adults
treatment for REM sleep behavior disorder
Medication (clonazepam)
consequences of sleep deprivation
accident/injury prone
Reduced memory capabilities
Reduced attention span
Lower immune system function
Buildup of waste products in brain
Increased sugar/carb cravings
Imbalance endocrine system
how often do we dream, when do they occur, what are they like?
5-7 times a night
occur during REM
Often negative, weird, or bizarre
