Sleep & Consciousness Flashcards
4 BEHAVIOURAL CRITERIA for sleep:
- Stereotypic or species-specific posture (i.e. humans sleep lying down typically)
- Minimal movement
- Reduced responsiveness to external stimuli
- Reversible with stimulation- unlike coma, anaesthesia or death
What are the three things that are usually measured when monitoring sleep
Eye movement (EOG) Muscle activity (EMG) Brain activity (EEG)
What happens to eye movement, muscle activity and brain activity in stages 1 and 2 of sleep?
The person is becoming more and more drowsy and the EEG activity is slowing
There are NO eye movements
The general muscle activity has been reduced considerably
Gradually you go from beta activity to theta activity (4-‐8 Hz)
What happens to eye movement, muscle activity and brain activity in stages 2 and 4 of sleep?
There is minimal eye movement at this point
There is continued relaxation of the muscles
This is very deep sleep
Lowest frequency delta activity of brain waves
What happens to eye movement, muscle activity and brain activity in stage 5 of sleep?
Brain activity shifts abruptly back to fast rhythm
This is quite similar to the activity you see in awake subjects
You get rapid eye movement even though the subject is asleep
The muscle activity is at its lowest so the person is basically paralysed
Which stage is REM sleep
5
How long is a cycle of the 5 stages of sleep
90 mins
Effect on HR and resp rate in REM sleep?
increase
Activity of the brain sequence in greek symbol terms
Awake = beta -> theta -> delta
Consciousness is mainly controlled by What
RETICULAR ACTIVATING SYSTEM
RETICULAR ACTIVATING SYSTEM does what
controls consciousness
LATERAL HYPOTHALAMUS does what
promotes wakefulness (orexin (or hypocretin) system- this promotes wakefulness)
VENTROLATERAL PREOPTIC NUCLEUS does what and where is it
in the anterior hypothalamus) promotes sleep
SUPRACHIASMATIC nucleus does what
synchronises sleep with falling light level
What part of the brain synchronises sleep with falling light level
SUPRACHIASMATIC NUCLEUS
What part of the brain (in the anterior hypothalamus) promotes sleep
VENTROLATERAL PREOPTIC NUCLEUS
What part of the brain promotes wakefulness (through orexin (or hypocretin) system- this promotes wakefulness)
LATERAL HYPOTHALAMUS
Where is the VENTROLATERAL PREOPTIC NUCLEUS found
Hypothalamus
Psychiatric and neurological EFFECTS OF SLEEP DEPRIVATION? (7)
- Sleepiness, irritability, stress, mood fluctuations, depression, impulsivity, hallucinations
neurological EFFECTS OF SLEEP DEPRIVATION? (3)
- Impaired attention, memory, executive function
- Risk of errors and accidents
- Neurodegeneration
Somatic EFFECTS OF SLEEP DEPRIVATION? (5)
- Glucose intolerance
- Reduced leptin/increased appetite
- Impaired immunity
- Increased risk of CVD and cancer
- Death
how is sleep REGULATED ACCURATELY? (After sleep loss…)
- Reduced latency to sleep onset (easier to get to sleep again)
- Increase of slow wave sleep (NREM)
- Increase of REM sleep (after selective REM sleep deprivation