Consciousness and brain activity L2 Flashcards
consciousness medical definition=
the state of being aware and responsive
what can levels of consciousness be plotted as
Awareness vs responsiveness
what cortex is involved in awareness and attention
parietal cortex
locked in syndrome=
fully conscious but paralysed
most common cause of loss of consciousness world wide
malaria
3 parts of assessment
Airways
breathing
cardiac output
what can be used to assess consciousness
glasgow coma scale
3 things Glasgow coma scale uses
eyes (4) verbal response (5) Motor response (6)
minimun score of glasgow coma scale
3
maximum score of glasgow coma scale
15
6 motor levels
none decerebrate decorticate withdraws localizes obeys
5 verbal levels
none incomprehensible inappropriate confused appropriate
4 eye levels of eye opening
none
to pain
to verbal command
spontaneous
what is a moderate to server score
9-11
what score is not in a coma
above 9
critical score=
8
above 12=
minor injury
brain stem death definition
irreversible loss of the capacity for consciousness + irreversible capacity to breath
what must the criteria for brain stem death not be caused by
depressant drugs
primary hypothermia
reversible endocrine, circulatory and metabolic disturbances
6 tests for brainstem death
pupil response corneal reflex vestibular-occular reflex cranial nerve motor response cough/ gag reflex respiratory effort
brain stem areas essential for consciousness (2)
reticular activating system (RAS)
cerebral cortex
what is the reticular activating system
a collection of nuclei found throughout the midbrain and extends into the hind brain and spinal cord
another name from the reticular activating system
Diffuse modulatory system
name 4 nuclei of the RAS
locus coeruleus
Raphe nuclei
ventral tegmental area
cholinergic nuclei
where is locus coerulus
pons
neurotransmitter of locus coerulus
noradrenaline
when is the locus coerulus active
arousal
novel stimuli
mediates sympathetic effects of stress
Disorders of locus coerulus
anxiety, panic , PTSD
where are Raphe nuclei
midline midbrain, pons and medulla
neurotransmitter of raphe nuclei
serotonin
role of Raphe nuclei
projections help regulate circardian rhythm
and pain inhibition
disorders of Raphe nuclei
depression
OCD
where is the Ventral tegmental area
ventral regions of midbrain
where does the ventral tegmental area project to
frontal cortex and limbic system
what does the ventral tegmental area do
reinforces pleasurable sensations
disorders of ventral tegmental area
addiction
schizophrenia
2 cholinergic nuclei
basal forebrain nuclei
dorsolateral pontine nuclei
neurotransmitter of cholinergic nuclei
Acetyl choline
what is the activated role of the cholinergic nuclei
states of arousal
induce wakefulness and REM sleep
learning and memory
disorders of Cholinergic nuclei
Alzeimers
amnesia
dementia
what area is associated with sleeping sickness
posterior hypothalamus damage
when awake what fibres fire
increased cholinergic fibre firing
when asleep what do fibres do
decreased cholinergic fibre firing
In wakefulness what need to happen to the thalamus
stimulate the thalamus and inhibit the inhibitory effect of the reticular nucleus
3 neurons that cause oscillations in EEG
Thalamocortical
reticular
corticothalamic
2 main stages of sleep
Non- REM sleep
REM sleep
which type of sleep is synchronised
non-REM sleep
which type of sleep is desynchronised
REM sleep
REM=
rapid eye movements
what type of frequency does REM cause
high frequency in EEG
another word for REM sleep
paradoxical sleep
which sleep is associated with dream
REM sleep
where do neurons in the retina project to
suprachiasmatic nucleus (SCN) of the thalamus
what does SCN secrete
vasopressin
what does vasopressin do in the brain
indirectly modulates the pineal gland to release melatonin
what is melatonin
a sleep promoting neurohormone
when does melatonin levels rise
just before a person is about to go to sleep
rare sleep disorder=
Narcolepsy
what does fMRI measure
glucose uptake in the brain
