Sleep Flashcards
Define alpha waves
the typical brainwave pattern (reasonably high frequency (but not as high as beta waves) and low amplitude (but slightly higher than beta waves)) that occurs when awake but very relaxed
Define amplitude
in relation to brain waves, the
intensity of brain waves as shown by the size of
the peaks and troughs of the brain wave pattern
from a baseline of zero activity
Define beta waves
typical brainwave pattern (high frequency
(fast) and low amplitude (small))
during normal waking consciousness,
associated with being alert, active,
anxious and paying (selective) attention.
Define deep sleep/ slow wave sleep
collectively stage 3 and stage 4 NREM
sleep
Define delta waves
the typical brainwave pattern (a steady
pattern of low frequency (slow) and high
amplitude (large)) associated with NREM
deep sleep.
Define frequency
in relation to brain waves, the number
of brain waves per second
Define hypnogogic (hypnic) jerks
a body spasm that may occur during
NREM stage 1 sleep
Define hypnogogic state
the relaxed state that occurs during the
transition from being awake to being
asleep, often considered to be part of
Stage 1 sleep.
Define K- complex
a burst of low-frequency and slightly
higher amplitude waves in response to arousing
stimuli during NREM stage 2 sleep
Define non- rapid eye movement sleep
one of two phases of sleep, characterised
by little or none rapid eye movement, and
often divided into four stages of NREM
sleep that are determined predominately
by predominant brain wave patterns.
Define rapid-eye movement sleep
one of two phases (REM and NREM) of sleep, characterised by rapid eye
movement, during which the eyeballs rapidly move beneath closed eyelids; constitutes about 20% of our sleep and is the period in which most dreaming occurs
Define sleep spindle
a brief burst of higher frequency
brain wave activity during NREM stage 2 sleep
Define somnambulism
sleep walking
Define theta waves
The typical brainwave pattern (medium
frequency and mixed amplitude (some
high, some low)) during the early
stages of sleep.
What are the physiological changes observed in NREM Stage 1?
- Eyes roll slowly
- Muscles relax
- Heart and breathing rate decreases
- Decreased body temperature and respiration
What are the physiological changes observed in NREM Stage 2?
- Eyes stop rolling
- Muscles become further relaxed
- Heart and breathing rate begins to decrease
- Blood pressure and respiration rate falls
What are the physiological changes observed in NREM Stage 3?
- Eyes do not move
- Muscles relaxed
- Heart and breathing rate becomes slower and more regular
What are the physiological changes observed in NREM Stage 4?
- No eye movement
- Little muscle activity
- Heart and breathing rate at their slowest and most regular
- Low respiration
Duration of NREM 1?
Ranges from 30 seconds to 10 minutes
- Typically lasts around 5 minutes
Duration of NREM 2?
Around 20 minutes
- Accounts for 50% of our sleep
Duration of NREM 3?
Takes place 20-50% of the time
Duration of NREM 4?
Around 30 minutes
Duration of REM?
First cycle is around 10 minutes, last cycle may occur for around 60 minutes
Why is dreaming called paradoxical sleep?
During dreaming, there are beta- like brain waves which are similar to the brainwaves when you are alert.
What are the physiological changes observed in REM?
Repetitive bursts of rapid eye movement
- Heart rate, blood pressure, respiration increase and fluctuate
What brainwaves are observed during NREM 1?
Alpha waves beginning to be replaced by theta waves
What brainwaves are observed during NREM 2?
Spindes, K- complexes, theta waves
What brainwaves are observed during NREM 3?
20-50% delta waves, rest are theta waves
What brainwaves are observed during NREM 4?
> 50% delta waves
What brainwaves are observed during REM?
fast beta-like waves (irregular, faster, smaller brain waves)
Define REM rebound
following a period of lost REM sleep, spending more time than usual in REM sleep when next asleep
Define microsleep
a very short period of drowsiness or
sleeping that occurs while a person appears to
be awake
Define electrocardiograph (ECG or EKG)
a device that detects, amplifies and records the electrical
activity generated by the heart
Define electroencephalograph (EEG)
a device that detects, amplifies and records electrical activity of the brain
Define electromyograph (EMG)
a device that detects, amplifies and records the electrical activity of
muscles
Define electro-oculargraph (EOG)
a device that measures eye movements or eye positions by detecting, amplifying and recording electrical
activity in eye muscles that control eye movements
Define sleep spindle
a brief burst of higher frequency brain wave activity during NREM stage 2 sleep
