Sleep Flashcards
What are electrooculograms and electromyograms used for?
Electrooculogram: measures eye movement
Electromyogram: measures facial muscle contraction/movement
Table compaing rate of brain activity, hertz, rhythm and muscle activity for each stage of sleep
(awake, NREM 1-2, NREM 3-4, REM).
What happens to HR and RR during REM sleep?
increased.
Outline the sleep cycle.
Cycle consists of NREM1-4 and REM sleep. Last 1-1.5 hours. Repeats.
ECG rhythm slows up to stage 4 and transitions to rapid rhythms in REM.
How does sleep change as the night progresses?
more slow wave sleep at the beginning of the night and more REM at the end
How does sleep regulation change with sleep deprivation?
More REM sleep
More slow wave sleep
Sleep onset is earlier
Sleep for longer
How does the RAS control consciousness?
Projects into cerebral cortex from brainstem to influence its activity.
Higher activity –> higher arousal
How does the RAS act both directly and indirectly?
Direct influence: directly synapses in the cerebral cortex
Indirect: uses intralaminar nuclei of the thalamus
What is the role of the lateral hypothalamus?
How does it do this?
promotes wakefulness - excitatory stimulation of RAS using orexin
active during day
What is the role of the ventrolateral preoptic nucleus? how does it do this?
Promote sleep.
Inhibits RAS.
Active during day.
Explain the relationship between the lateral hypothalamus and the ventrolateral preoptic nucleus.
antagonistic, so activation of one inhibits the other (LH active at start of day and VLP at end
What is the role of the suprachiasmatic nucleus?
synchronise sleep with falling light level.
How does the SC nucleus function?
receives input from ganglion cells in retina, and as light levels fall, SC nucleus becomes more active, activating hypothalamic nuclei to inhibit the LH and stimulate the VLP nucleus
Where is the pineal gland located?
back of the third ventricle.
What does the pineal gland secrete? What does this hormone do?
melatonin.
Modulate sleep.
