SLEEP

Question 1

Sleep is characterized by

Answer 1

Altered consciousness.
Minimal motor & sensory activity.
Specific pattern of brain activity.
Reduced interactions with the external world.

Question 2

what is electroencephalography

Answer 2

is an electrophysiological monitoring method to record electrical activity of the brain, with electrodes placed along the scalp.

Question 3

emg is used to

Answer 3

Monitor sleep stages & diagnose sleep disorders (Polysomnography).
Diagnose neurological disorders (e.g. epilepsy, encephalopathies, stroke…).
Monitor coma, brain death and anesthesia level

Question 4

brain wave when highly alert and eyes open

Answer 4

low ampltude and high frequency

Question 5

brain wave when ayes closed and relacx

Answer 5

low amplittude and high frequency

Question 6

brain wave during drowsy

Answer 6

high amplitude and low frequency

Question 7

brain wave during deep sleep

Answer 7

high amplitude and low frequency

Question 8

what are the 2 states of wakefulness

Answer 8

active: eye open, activate state
resting wakefullness: eye closed, relaxed state

Question 9

2 state of sleep

Answer 9

Non-rapid eye movement sleep (non-REM): composed of 4 stages:
Stage I
Stage II
Stage III
Stage IV
rapid eye-movement (REM) sleep

Question 9

2 state of sleep

Answer 9

Non-rapid eye movement sleep (non-REM): composed of 4 stages:
Stage I
Stage II
Stage III
Stage IV
rapid eye-movement (REM) sleep

Question 10

wave during wakefulness

Answer 10

Beta & Alpha waves: high EEG frequency (9–30 Hz) & low EEG amplitude (∼30 µV).

Question 11

wave during stage 1 sleep weakfulness

Answer 11

Theta waves: intermediate EEG frequency (5–8 Hz) & intermediate EEG amplitude (50 – 100 µV) and K-Complex (isolated slow wave).

Question 12

wave during stage 2 wakefulness

Answer 12

Theta waves and sleep spindle: high EEG frequency (11–15 Hz) & low EEG amplitude (50 µV).

Question 13

wave of stage 3 and 4 of wakefulness

Answer 13

slow waves (delta waves): low frequency (0.5 to 4 Hz) & high EEG amplitude (100 – 150 µV).

Question 14

REM sleep: Beta & Alpha waves

Answer 14

high EEG frequency (9–30 Hz) & low EEG amplitude (∼30 µV). The same as in Wakefulness.

Question 15

caracteristic of REM sleep (paradoxical sleep)

Answer 15

High EEG frequency (10–30 Hz) & low EEG amplitude (∼30 µV), Beta & Alpha waves. The same as in wakefulness,
Rapid eye movements (REM): eyelids closed,
Minimal muscle tone, muscle atonia (i.e. muscle paralysis),
Transient muscle activity (i.e. jerky muscle activity),
Predominance of dreams.

Question 16

how long is approx each sleep cycle

Answer 16

90 min and about 4 to 5 cycle per night

Question 17

how does non-REM is throught the night

Answer 17

Non-REM sleep is longer at the beginning of the sleep but as the sleeper becomes more rested through the night, the durations of non-REM decrease.

Question 18

how is REM sleep throught the night

Answer 18

REM sleep is short at the beginning but becomes long at the end.

Question 19

During wakefulness the cerberal cortex and thalamus are kept excited by

Answer 19

neurons of the Ascending Arousal System located at the subcortical level:

Question 20

what composed the subcortical level

Answer 20

brainstem, hypothalamus, basal forebrain

Question 21

during wakefulness wakefulness the cortex and thalamus are kept excited by

Answer 21

neurons of the Ascending Arousal System located at the subcortical level.

Question 22

cortical neuron discharge AP with which pattern and this result in

Answer 22

Cortical neurons discharge APs with fast & irregular patterns (i.e. not at the same time), which results in a low amplitude and fast frequency EEG activity: ‘desynchronized EEG’

Question 23

during wakefulness The arousal system neurons stimulate also

Answer 23

motor neurons in the spinal cord to keep a higher muscle tone during wakefulness.

Question 24

during non-rem sleep what happen with inhibitory neurons

Answer 24

Inhibitory neurons (mainly GABA) located in the Hypothalamus (Ventrolateral Preoptic nucleus, VLPO) inhibit the neurons of the arousal system to promote sleep.

Question 25

cortical and thalamis neuron switch to what and result to what

Answer 25

Cortical and thalamic neurons switch to a slow & rhythmic discharge patterns (i.e. discharge all at the same time), which results in a high amplitude and slow frequency EEG activity: ‘synchronized EEG’ activity (i.e. slow- waves sleep).

Question 26

which neuron are reactivated during REM sleep and what they do

Answer 26

the brainstem Acetylcholine neurons are re-activated and send also their descending fibers to excite medullar and spinal inhibitory interneurons, which in turn inhibit spinal motor neurons

Question 27

the inhibition of nmotor neuron in REM sleep lead to what

Answer 27

leads to a significant decrease of muscle tone, muscle atonia (i.e. muscle paralysis

Question 28

most of dreaming occurs when

Answer 28

during REM sleep

Question 29

what is sleep homeostatic

Answer 29

Process S (Sleep Homeostatic): sleep propensity (i.e. sleep need) accumulates across the day: The more the person stays awake, the more the sleep propensity incerased. The more the person stays asleep, the more the sleep propensity decerased.

Question 30

what is circadian

Answer 30

Process C (Circadian): biological clock, under the control of the hypothalamus: Follows the light-dark cycle. Releases sleep-related hormones (e.g. Melatonin).

Question 31

what is circadian

Answer 31

Process C (Circadian): biological clock, under the control of the hypothalamus: Follows the light-dark cycle. Releases sleep-related hormones (e.g. Melatonin).

Question 32

sleep function

Answer 32

sleep is important for physical, cognitive and psychological well-being (i.e. sleep is a vital function): Resting of different parts of the body. Restore natural balances among the neuronal centers. Acceleration of neural maturation (need of sleep for youth). Facilitation of learning and memory (neuronal plasticity). Clearance of metabolic waste products generated by neural activity in the awake. Conservation of metabolic energy. Hormonal regulation.

Question 33

what is insomnia

Answer 33

is a Non-REM Sleep deficiency characterized by a perceived inability to fall and remain asleep at night, although it may not represent a true inability to sleep (paradoxical insomnia = sleep state misperception).

Question 34

what is hypersomnia

Answer 34

is a Wakefulness deficiency characterized by excessive daytime sleepiness. It is a failure in the activating of mechanisms that are necessary to maintain arousal during the day.

Question 35

what is narcolepsy

Answer 35

is a REM sleep dysfunction seen in the form of sudden REM sleep onset from wakefulness (sleep atacks) and excessive daytime sleepiness. It is often associated with cataplexy (muscle paralysis) following a emotional reaction

Question 36

narcolepsy is caused by what

Answer 36

loss of orixin neuron in hypothalamus

Question 37

what is sleep walking

Answer 37

is a Non-REM Sleep dysfunction characterized by a partial arousal (with low consciousness) from Non-REM sleep and performing activities that are usually performed during wakefulness (e.g. walking out of the room, eating, sex, driving, homicide…). A total amnesia of the event (i.e. do not recall the event).