Sleep & EEG Flashcards
What cues contribute towards circadian rhythm
environmental, external
What is the suprachiasmatic nucleus?
major internal clock
Where is the suprachiasmatic nucleus located?
anterior hypothalamus
What is the function of the retinohypothalamic tract
entrain internal clock, receive APs
How is the circadian rhythm affected by lesions in the suprachiasmatic nucleus
dampens down
What does the suprachiasmatic tract connect?
eye to suprachiasmatic nucleus
What does the suprachiasmatic nucleus regulate
timing of sleep
What are the two stages of Sleep
REM and non-REM
What defines sleep
reduced motor activity, reduced response to stimuli
What is REM
rapid eye movement
Which electrical recording measures muscle movements
electromyography
Which electrical recording measures eye movements
electro-oculography
Which electrical recording measures brain activity
electroencephalography
What does an electroencephalogram measure
synchronous electrical activity of large population of neurons
What causes electrical activity in the electroencephalogram
movement of ions during action potentials - electric field
What are the advantages of an electroencephalogram
non-invasive, easy to administer, data gathered easily
TRUE or FALSE - electroencephalograms have high temporal resolutions
True
TRUE or FALSE - electroencephalograms have high spatial resolution
False
Where do EEGs record events ?
cortex
What is non-REM sleep characterised by
low neuronal activity, low HR and BP, low metabolic rate
What are the characteristics of stage 1 sleep?
slow eye movement, slow muscle activity, muscle jerkiness
Describe the EEG of stage 1 non-REM sleep
low voltage activity, sinusoidal type activity, varying frequencies
What are the characteristics of Stage 2 non-REM sleep
no eye movements, slow brain waves, HR slows, body temp drops
What is the EEG of Stage 2 sleep characterised by
bursts of sinusoidal activity, biphasic K complex waves, low background voltage
What are the characteristics of Stage 3 non-REM sleep
sleep talking, bed wetting, night terrors, transition
What is the EEG of stage 3 non-REM sleep
high amplitude slow delta waves interspersed with faster waves, occasional bursting
What are the characteristics of Stage 4 non-REM sleep
very deep, disorientation, eye lolling,
Describe the EEG of stage 4 non-REM sleep
delta waves exclusively, slow waves, large amplitude slow changes
What cause the large amplitude very slow EEG changes in stage 4 non-REM sleep?
depolarisations on the surface of the brain
What are the characteristics of REM sleep
darting eye movement, intense dreaming, paradoxical sleep
Describe the body during REM sleep
increased brain temp and metabolic rate, paralysis, increased parasympathetic system
Describe the pupils during REM sleep
constricted
Describe the EEG of REM sleep
mimics wakefulness, similar to stage 1, low voltage mixed frequencies
Neurons in which areas fire most intensively during REM sleep
pons, lateral geniculate nucleus, occipital cortex
What does intense firing generate in the REM sleep EEG
high voltage spike potentials - PGO spikes
Where do PGO spikes originate
pontine reticular formation
What do the PGO spikes travel through?
lateral geniculate nucleus to the occipital lobe
What is the function of the lateral geniculate nucleus
vision
Where is the primary visual cortex located
occipital lobe
What do the PGO spikes correlate with
bursts of rapid eye movements
How responsive is the body to changes in blood CO2 during REM sleep
unresponsive
TRUE or FALSE - the normal sleeping pattern is non-cyclic
FALSE
