sleep and consciousness Flashcards
(15 cards)
what controls consciousness?
reticular activating system
what promotes wakefulness and what promotes sleep?
wakefulness- lateral hypothamamus
slpeeo- ventrolateral preoptic nucleus
how is sleep controlled?
suprachiasmic nucleus syncronises sleep with falling light level
sends signal to pineal which secreats melatonin
melatonin traps the light and secretion goes up during the day which makes you more tired
what are the effects of sleep deprivation?
Psychiatric and neurological – Sleepiness, irritability, stress, mood fluctuations, depression, impulsivity, hallucinations • Neurological – Impaired attention, memory, executive function – Risk of errors and accidents – Neurodegeneration (?) • Somatic – Glucose intolerance – Reduced leptin/increased appetite – Impaired immunity – Increased risk of cardiovascular disease and cancer – Death
what are the functions of sleep?
memory consolidation
rest and restoration (but active people dont sleep more)
where is brain activity most active during dreaming
limbic system
contents of dreams more emotional
what are some causes of insomnia?
– physiological e.g. sleep apnea, chronic pain
– Brain dysfunction eg. depression, fatal familial
insomnia, night working
what is sleep hygiene?
improving sleep quality
• establishing fixed times for going to bed/waking up
• creating a relaxing bedtime routine
• only going to bed when you feel tired
• maintaining a comfortable sleeping environment
• not napping during the day
• avoiding caffeine, nicotine and alcohol late at night
• avoiding eating a heavy meal late at night
• don’t use back-lit devices shortly before going to bed
what is narcolepsy?
falling asleep repeatedly during the day and disturbed sleep during the night
dysfunction of control of REM sleep
orexin/hypocretin deficiency
what is consciousness?
the state of being aware and responsive to ones surroundings
the subject experience of the mind and the world around us
what is the mechanism of consciousnes?
reticular activating system (enables consciousness)- thalamocortical system
cannot work without the RAS
there is no single brain region for consciousness
The reticular formation (RF) regulates many vital
functions. The degree of activity in the reticular system is
associated with alertness/levels of consciousness
• RF projects to the hypothalamus, thalamus and the
cortex
• Ventral tegmental area (dopaminergic neurones)
(midbrain)
• Locus coeruleus (noradrenergic neurones) (pons)
what are brain networks?
groups of brain regions that work together to perform functions
eg. default mode network is important for consciousness of self, mind wondering, focussing of thoughts, planning what you will do in the future
what is the glasgow coma scale?
The Glasgow coma scale (GCS) is a tool used to assess and calculate a patient’s level of consciousness.
The GCS uses a triple criteria scoring system: best eye opening (maximum 4 points),
best verbal response (maximum 5 points),
and best motor response (maximum 6 points). These scores are added together to provide a total score between 3 and 15
what are some causes of coma?
Metabolic – Drug overdose – hypoglycaemia – diabetes – "the failures" – hypercalcaemia
Diffuse intracranial – head injury – meningitis – SAH – encephalitis – epilepsy – hypoxic brain injury
Hemisphere lesion – cerebral infarct – cerebral haemorrhage • subdural • extradural – abscess – tumour
Brain stem – brainstem infarct – tumour – abscess – cerebellar haemorrhage – cerebellar infarct
what is diffuse axonal injury?
damage to the white matter tracts of the brain reducing communication between areas of the brain
