Stages of sleep and sleep mechanisms Flashcards
a state actively produced by the brain, characterized by decreased activity and response to stimuli
Sleep
Extended period of unconsciousness caused by end trauma, stroke, disease. Low brain activity little response to stimuli
Coma
Alternates between periods of sleep and moderate arousal. Shows no awareness of surroundings and no purposeful behavior during mod arousal. Can last for years.
Vegetative state
Brief periods of purposeful actions and a limited amount of speech comprehension. Can last for years.
Minimally conscious state
No sign of brain activity and no response to any stimulus. Declared after 24h of no brain activity.
Brain death
Combination of EEG and eye-movement records are used to produce it.
Polysomnograph is a combination of ___ and ___
Have a frequency of 8 to 12 per second. Characteristic of relaxation
Alpha waves
sharp wave associated with temporary inhibition of neuronal firing
K-complex
burst of 12- to 14-Hz waves for at least half a second. Result from oscillating interactions between cells in the thalamus and the cortex
Sleep spindle
Increase in number after new learning.
Correlates positively with improvements in certain types of memory
Number of sleep spindles increase in number after ___
Correlates positively with___
heart rate, breathing rate, and brain activity decrease
& slow, large-amplitude waves become more common
Indication that neuronal activity is low and highly synchronized
Indicator for ↑ because input to the cerebral cortex is greatly inhibited, and most cells synchronize their activity
3 things about Slow wave sleep
Characteristics
Indication of ___
Why does it indicate it?
___ : REM sleep = Animals without eye movements : Animals with eye movements
Paradoxical sleep : REM sleep = ___ : Animals with eye movements
