Sleep Flashcards
What is sleep?
A normal recurring reversible state in which you loose the ability to respond to the external environment.
Not fully aware of self but able to respond to stimuli
Non REM sleep
More common at the beginning of the night
Some non narrative images
What proportion of sleep for the young in NREM?
3/4
What does an EEG show in NREM?
Synchronised rhythmic activity
Describe the physiological state found in NREM.
Partial muscle relaxation
Reduced cerebral blood flow
Reduced HR BP Tidal volume
What does REM stand for?
Rapid Eye Movement
Describe REM sleep.
Mostly at the end of the night.
Narrative dreaming
What does an EEG show in REM?
Fast activity
Describe the physiological state found in REM.
Atonic muscles except diaphragm and extra ocular
Increased cerebral blood flow
Impaired thermal regulation
Increase active shown on brain fMRI
Why is deep sleep essential?
Allows the cortex to recover
If you are sleep deprived and finally manage to fall asleep for a short period what form of sleep is prioritised?
Deep sleep
What is the function of REM sleep?
Mainly plays a roll in brain development
Substitute for stimulation from the external environment
REM sleep is indispensable.
False it is likely to be dispensable as Dolphins don’t have an REM cycle and drugs such as Tricyclics suppress it.
Describe the sleep of a neonate.
16hrs a day roughly a sleep.
50% is REM in order to provide enough stimulation to the developing brain.
As you get older the proportion of REM sleep you experience …….
Decreases
Describe the sleep of an elderly person.
Increased awakening during the night
Naps throughout the day
REM is reduced
Overall time asleep is reduced
What three things dictate if you can fall asleep?
Homeostatic
Emotional
Circadian rhythm
What is the homeostatic factor in sleep?
Longer you are awake the more sleepy you get as you build up a sleep debt.
What is the emotional factor in sleep?
Need to be in a state of relaxation ad comfortable enough to sleep.
What is the circadian rhythm?
Your internal body clock controlled by the light .
What length cycle does your body clock run?
25 hours
What is the sleep pattern on an adolescent?
Delayed
What is the sleep pattern of the elderly?
Early
What else does your circadian rhythm control?
Appetite
Thermoregulation
Hormone regulation
Alertness
How does light affect your circadian rhythm?
Retinal ganglion cells enervated which project to the suprichiasmatic nucleus
What cells make up the retinal ganglion cells involved in the circadian rhythm?
Non cone Non rod cells
What colour light particularly affects your circadian rhythm?
Blue light
After 5 days of no sleep why is your endurance in exercise reduced?
Sleep has no recorded impact on your physiological state your endurance is reduced due to psychological fatigue.
Describe the affect of sleep on your body repairing itself.
No affect on muscle recovery
Tissue repair is increased
Why is tissue repair increased during sleep?
Release of sleep related growth hormone SRgh
Which areas of the brain require the most sleep?
Cortical regions of the brain controlling complex function
When awake can regions of the brain rest whilst not in use?
No the cortex stays in a state of quiet readiness
What are some of the affects of prolonged sleep deprivation?
NO psychcosis
Irritable, Suspicious, Visual illusion, Loss of concentration, Visual illusions, Reduced alertness
Which region of the brain is responsible for most the symptoms of sleep deprivation?
Prefrontal
How does sleep kill?
Not directly
Most accidents occur around 4am.
reduced alertness communication and decision making skills.
What is an acceptable duration of sleep?
7-7.5 hours
What is the ideal duration of nap and how much normal sleep is it worth?
15 mins is equivalent to 90 mins during the night
Describe parasomnia during REM sleep.
None of the usually atonia.
Interact with the dreams e.g simple movement kicking etc
Occurs in last 1/3 of the night
Describe parasomnia during NREM
Complex behaviours
Between waking up and actually being awake
What are the main symptoms on narcolepsy?
Daytime sleepiness Cataplexy Hypnagogic hallucinations RBD - REM behaviour disorders Sleep Paralysis
Describe daytime sleepiness associated narcolepsy.
Involuntary and irresistible somnolence that can occur during any activity.
What is cataplexy?
Loss of all muscle tone triggered by severe and sudden emotion
Jaw weakness and collapsing
What proportion of narcolepsy patients present with cataplexy?
70%
Epidemiology of Narcolepsy.
M:F 1:1
Onset has two peaks 15y to 36y
When do hypnagogic hallucinations occur with narcolepsy?
Occurs at the onset of sleep
What are hypnogogic hallucinations?
Very vivid and lucid dreams
What are RBD REM behaviours disorders?
Acting out of dream
What is the social impact of narcolepsy?
Reduced social and academic outlook
Reduced employability
Social embarrassing
What investigations should be undertaken for narcolepsy?
Overnight polysomnographs
Multiple sleep latency tests
Lumbar puncture
What is observed in the multiple sleep latency test?
REM sleep is reached much faster
What is seen on lumbar puncture in narcolepsy?
Increased hypocretin
Neither specific or sensitive
If someone with narcolepsy is a driver what must happen?
Not allowed to drive until control is achieved
Permanently excluded from a type 2 licence
