sleep

Question 1

what are the behavioural criteria of sleep

Answer 1

minimal movement

sterotypic/species specific posture - atonia

reduced responsiveness to external stimuli

reversible with stim

Question 2

wat are the stages of sleep *

Answer 2

awake

stage 1 and 2 - non rem (NREM)

3 and 4 - NREM

5 - REM

Question 3

what does an emg show

Answer 3

muscle activity around teh jaw

Question 4

what does an eog show

Answer 4

eye movement

Question 5

what is a feature of stage 3 and 4 sleep *

Answer 5

slow HR and rhythm

Question 6

what is a feature of stage 5 sleep *

Answer 6

REM

busy eog

HR increase

eeg - similar to awake- rapid

usually when dreaming

Question 7

what is the length of a sleep cycle *

Answer 7

90mins

Question 8

feature of stage 2 sleep *

Answer 8

sleep spindle on eeg - like a signiture - buts of energy

Question 9

describe the maintenance of arousal *

Answer 9

reticular actiavting system controls consciousness - enables consciousness, but not where consciousness is stored

stems from brainstem and projects to thalamus and cortex

Question 10

describe the control of the sleep wake cycle *

Answer 10

lateral hypothalamus promotes wakefulness - using neurotransmitters orexin/hypocretin - stimulates the reticular activating system and keeps you awake

ventrolateral preoptoc nucleus (anterior hypothalamus) promotes sleep - negative force on RAS

Question 11

explain how sleep is syncronised to day length *

Answer 11

supraciasmatic nucleus synchronises sleepo with falling light level

level of ambient light is tracked and fed into system

suprachiasmatic nucleus stimulates melatonin release when dark from pineal glands - makes you sleepy

Question 12

what are the effects of sleep deprivation *

Answer 12

psychiatric and neurological - sleepiness, irritability, stress, mood fluctuations, depression, impulsivity (siezures and convulsions), hallucinations

neurological - impaired attention, mem and executive func, risk of errors and accidents, perhaps neurodegeneration - dementia

somatic - glucose intolerance, reduced leptin/increased appetite, impaired immunity, increased risk of cardiovascualar disease adn cancer, death

different pattern of brain activity when you do tasks wen sleep deprived

Question 13

how is sleep controlled after sleep loss *

Answer 13

reduced latency to sleep onset - faster to get to sleep

increase of slow wave sleep - NREM
increase of REM sleep - after selective REM sleep deprivation

Question 14

what are the functions of sleep *

Answer 14

restoration and recovery - but active people dont sleep more

energy conservation - 10% drop in basal metabolic rate, but same as just lying still

predator avoidance - but why is sleep so complex

memory consolidation

Question 15

what are dreams *

Answer 15

can occur in REM or NREM - more likely in REM

more recalled in REM

more emotional than real life - more limbic system than frontal lobe - idea of self, emotional regulation

lucid dream - know in a dream but continue to dream

Question 16

what are the functions of dreams *

Answer 16

safety valve for antisocial emotions

disposal of unwanted memories

memory consolidation

or SE of way the brain functions in day - not functional

Question 17

what is insomnia *

Answer 17

high prevalence

most cases transient

have functional impact on life - ie start to sleep in day

usually from lifestyle - rare to see chronic causes

causes of chronic cases - physiological eg sleep apnoea/chronic pain, brain dysfucntion eg depression/fatal familial insomnia/nighht working

treatment - sleep hygiene, hypnotics (most enhance GABAergic circuits), sleep cognitive behavioural therapy

Question 18

how can you improve sleep disturbance

Answer 18

sleep hygiene:

establish fixed time for bed/waking

creating relaxing bedtime routine

only go to bed when feel tired - dont work on bed

maintain comfortable sleeping environment

not napping

avoid caffiene, nicotine and alcohol late at night

avoid hheavy meal late at night

dont use back lit devices before bed

Question 19

what is hypersomnia *

Answer 19

excessive daytime sleepiness

Question 20

secondary causes of hypersomnia *

Answer 20

obstructive sleep apnoea - because normal sleep cycle disturbed

restless leg syndrome and periodic limb movements of sleep

nocternal pain - diabetic neuropathy/arthritis

neurodegenerative disease - parkinsonism

medication - hypnotic misuse

env factors - noise

anxiety

rare - oesophageal acid reflux, severe bruxism

Question 21

primary causes of hypersomnia *

Answer 21

narcolepsy

idiopathic hypersomnolence

post-TBI

Question 22

describe the epworrth sleepiness scale

Answer 22

pt rate item from 0-never dose to 3 - high chance, higher score = more sleepiness

• sitting and reading
• watching TV
• sitting in interactive public space - theatre or meeting
• lying down to rest in afternoon
• sitting and talking to someone
• sitting quietly after lunch w/o alcohol
• sitting in car while stopped for a few min in traffic

Question 23

what is narcolepsy *

Answer 23

falling asleep during the day repeatedly, and disturbed sleep at night

cataplexy - sudden, brief loss of vol muscle tone, often triggered by stong emotions eg laughter

dysfunction of control of REM sleep

orexin/hypocretin deficiency

Question 24

how can shift work affect sleep

Answer 24

night work causes physiological processes to become desynchronised

this can lead to sleep disorders, fatigue and an increased risk of obesity, diabetes and cancer

Question 25

describe sleep and neurological disease *

Answer 25

sleep disturbance can cause neurological disease, or other way

abnormalities in sleep before neurological disorder - eg REM behavioural disorder - cause of lewy body dementia/early manifestation