11 Flashcards
(13 cards)
What types of recordings are part of a polysomnogram? What are they measuring, and why
is this important?
EEG- measures electrical activity in the brain
EOG- measures eye movements
EMG- measures muscle activity
Important because you must see if there’s any irregularities contributing to the need of this test.
What kind of waves during normal awake time on EEG? (amplitude, frequency, name)
frequency: 13-30 Hz
Beta waves
low amplitude
What kind of waves during relaxation on EEG? (amplitude, frequency, name)
Alpha waves
8-13 Hz
moderate amplitude
What 2 phenomena during stage 2 sleep on EEG?
Stage 2 sleep on the EEG shows sleep spindles → (a short segment of Alpha waves : brief bursts of high-frequency brain activity) and K complex → (this is a precursor of Stage 3: sharp, high-amplitude waveforms))
What kind of waves during deeper sleep (3 & 4) on EEG? (amplitude, frequency, name)
Delta Waves (Deep Sleep)
N3: is known as stage 3 AND 4 in deep sleep
.5-4 Hz, High amplitude
What is NR3 or N3?
Stages 3 & 4 of sleep (deep sleep)
What is the general trend in the amplitude/frequency from awake to deep sleep?
Beta waves (alert stage) have low amplitude and high frequency. Delta waves (deep sleep) have high amplitude and low frequency.
How are the waves on an EEG during coma? How are they different from delta waves?
A coma is not deeper sleep, the EEG for a coma shows very slow, low amplitude waves
They are different from delta waves because they have a high amplitude whole coma waves have a low amplitude and a low frequency
Explain the sleep cycles that one goes through in a normal night (both stages and
REM/NREM alternation)
n1- transfew from awake to sleep(muscle twitches, falling feeling)
n2-light sleep
n3- deep sleep
REM- vivid dreams
75 % of sleep is spent in NREM and 25% is spent in REM. Every 90 minutes you go down and then back up again.
REM: eye movements but no muscle movements
NREM: no eye movements but muscle movements
What is the trend for Slow wave sleep and REM sleep during the night? How many REM
cycles during a ‘normal’ night?
Trend of about 90 minute from stage 1 sleep to first REM. Average of 5 cycles per night
What are the differences between REM and NREM sleep w.r.t. movement of body parts
(eyes, limbs etc).
Rapid Eye Movement: typically go through 5 periods of REM and sleep cycles, and tend to wake up after. Spinal nerves are suppressed, and eye muscle contractions
NREM: sleep walking can occur, 75% of your sleep, when memory consolidation takes place, and parasomnia can also occur. Body repairs itself and strengthens the immune system
How does the % of REM sleep change during your lifespan? (infants, grandparents)
Babies a lot of REM (80%), Old people shorter sleep less REM ( probably 10%) , Adults 25 %
What is the circadian rhythm? Which sensory system acts on which part of the brain? What
does the pineal gland have to do with the circadian rhythm? How does entrainment of the
circadian system work (generally)?
Circadian rhythm is the rhythm of the day. It is in charge of when you’re sleeping. The visual system acts on the suprachiasmatic nucleus (part of the hypothalamus)
as light strikes the eye (the retina). It cues the body to have a 24 hour days. This system is entrained by light. The pineal gland is in charge of secreting Melatonin which helps to make you fall asleep.
