sleeping

Question 1

electroencephalogram (EEG)

Answer 1

a machine that records an average of the electrical potentials of the cells in the brain areas nearest to each electrode on the scalp

Question 2

stage 1 sleep

Answer 2

• EEG is a low-voltage, high-frequency signal
• brain activity is less than in relaxed wakefulness but more than other sleep stages

gradual increase in EEG voltage & decrease in EEG frequency while progressing from stage 1 to 2 & 3

Question 3

stage 2 sleep

Answer 3

EEG has a slightly higher amplitude and a lower frequency than stage 1 EEG

has K complexes & sleep spindles

Question 4

k complex

Answer 4

a sharp wave associated with temporary inhibition of neural firing

Question 5

sleep spindle

Answer 5

a burst of 12-14 Hz waves for a least half a second
- result from fluctuating interactions between cells in the thalamus and the cortex

Question 6

stage 3 sleep (slow wave sleep)

Answer 6

EEG has a predominance of delta waves (largest & slowest EEG waves)

• heart rate, breathing rate & brain activity decrease
• slow, large-amplitude waves become more common
• input to cerebral cortex is greatly inhibited & cells synchronize activity

Question 7

REM sleep

Answer 7

periods of rapid eye movement that occur during sleep - all other stages are called NREM sleep (non-REM)

• EEG is low-voltage, fast waves – indicate increased neuronal activity
• heart rate, blood pressure, breathing rate & facial twitches fluctuate during REM more than other stages
• amount depends on time of day more than how long you have been sleeping
• only occurs when a network of independent structures become active together