T22. WAKEFULNESS AND SLEEP Flashcards
(34 cards)
What is sleep?
Sleep is a naturally recurring state of mind and body, characterized by altered consciousness, inhibited sensory activity, reduced muscle activity, and decreased interactions with surroundings.
How is sleep distinguished from wakefulness?
Sleep is distinguished by a decreased ability to react to stimuli but it is more reactive than a coma or other disorders of consciousness
What processes are restored during sleep?
Sleep helps restore the immune nervous
What are circadian rhythms?
Circadian rhythms are cycles of events that recur about every 24 hours related to sleep and other bodily functions.
What is sleep paralysis?
Sleep paralysis is a state where there is inhibition of muscular activity during sleep.
What is the difference between sleep and coma or hibernation?
Sleep is a reversible state where one can be aroused while coma or hibernation are states of prolonged unconsciousness where one cannot be aroused by sensory stimulation.
What is an EEG?
An EEG (electroencephalogram) measures brain activity through electrodes placed on the scalp detecting electrical potentials produced in the cerebral cortex.
What does an EEG record?
An EEG records the brain’s spontaneous electrical activity over time which shows brain wave patterns.
How are brain waves determined?
Brain waves are determined by the level of excitation in different parts of the brain during sleep wakefulness
What is the significance of the absence of brain waves?
The persistent absence of brain waves is a common clinical and legal criterion for brain death.
What types of brain waves are there?
There are four brain wave patterns: Alpha and Beta
What is the Alpha brain wave pattern associated with?
Alpha waves occur during daydreaming when awake but resting with eyes closed and mind wandering. It is suppressed when eyes open or performing a mental task.
What is the Beta brain wave pattern associated with?
Beta waves occur during alertness when the eyes are open and performing mental tasks accentuated during mental activity and sensory stimulation.
What is the Theta brain wave pattern associated with?
Theta waves are present during drowsiness or sleep in adults. If seen in awake adults it indicates severe emotional stress.
What is the Delta brain wave pattern associated with?
Delta waves are seen during deep sleep in adults and in awake infants.
What are the two types of sleep?
Sleep consists of Slow-Wave Sleep (Non-REM) and Rapid Eye Movement (REM) Sleep.
What happens during Slow-Wave Sleep (Non-REM)?
In Slow-Wave Sleep neurons decrease their firing rates
What characterizes REM sleep?
REMS is characterized by random rapid eye movements low muscle tone
What happens during Slow-Wave Sleep at a cellular level?
The brain waves are strong and of low frequency and the body may repair metabolic damage done by free radicals and engage in neuroplasticity.
How is Slow-Wave Sleep divided?
Slow-Wave Sleep is divided into four stages based on EEG waves: very light sleep light sleep
What happens in stage 1 of Slow-Wave Sleep?
In stage 1 the EEG voltage becomes very low
What happens in stage 2 of Slow-Wave Sleep?
In stage 2 the individual progresses into light sleep.
What happens in stage 3 of Slow-Wave Sleep?
In stage 3 the person enters moderate to deep sleep
What happens in stage 4 of Slow-Wave Sleep?
In stage 4 low-frequency
