Physiology Of EEGs And Sleep

Question 1

_________ nucleus is the Body’s clock?

Answer 1

Suprachiasmatic

Question 2

______ and ______ are produced in the suprachiamtic nucleus to produce to circadian rhythm

Answer 2

CLOCK and BMAL1

CLOCK no circadian rhythm
BMAL1- increases at night
—increase transcription of period and Cryptochrome gens

Question 3

How long is the day the SCN creates?

Answer 3

25 hours

Question 4

How do we match the SCN day to the 24 hour day?

Answer 4

Receive light/dark information from eye=>retino-hypothalamic tract=> hypothalamic (direct)=> glatmate (light) or melatonin (dark)

Question 5

Describe the sleep architecture?

Answer 5

Non-Rem sleep 
—most time asleep
—three stages
—progressive slowing of EEG waves
—boring, rehashing dreams
REM sleep
—rapid eye movement 
—EEG: low amplitude, higher frequency waves
—vivid dreams

Question 6

_________ ______ ____ is crucial to sleep induction

Answer 6

Central Preoptic area (VPO)

Question 7

How does the Ventral Pre-optic region induce sleep?

Answer 7

1. Increase PGD2 in the blood
2. Binds DP receptors on the leptomeninges
3. Lepotmeninges release Adenosine into the CSF
4. Adenosine binges A2 receptors in the VPO
5. Actives VPO neurons and inhibits Ascending Reticular Activating System (ARAS)
   —mainly cholinergic inputs

Question 8

How is REM Sleep initiated?

Answer 8

Cholinergic neuron in the lateral pontine tegmentum

1. Release Ach in the Geniculate body
2. Send input to the occipital cortex

Question 9

What inhibits large muscle during REM sleep?

Answer 9

Louis ceruleus: inhibitory input to alpha-motor neurons

Spares diaphragm and small muscle groups

Question 10

How is waking up induced?

Answer 10

Hypothalamus
1.Lateral hypothalamus
—Orexin A and B. Hypocritical 1/2)

2. Sent to the tuberomamillary nucleus
3. Histamine is releases binding to H1 receptors, activation the LC neurons
4. LC releases norepinephrine and suppress REM sleep

Question 11

When does the EEG change?

Answer 11

Degrees of activity in the brain
Arousal/awareness
Sensory input
Pattern=pathology

Question 12

What are the 5 different Normal waves of the EEG?

Answer 12

Alpha
Beta
Gamma
Theta
Delta

Question 13

Describe Alpha waves?

Answer 13

8-13 Hz
50 microvolts
Occur during quiet wakefulness (thinking) with eyes closed
Most prevalent over occipital cortex
Require connection between thalamus and cortex

Question 14

Describe Beta waves?

Answer 14

14-80 Hz
<50 microvolts
Occur during alert wakefulness with eyes open
Most prevalent over frontal cortex (also parental cortex)

Question 15

Describe alpha block?

Answer 15

With sensory input (opening eyes)
Alpha waves cease and beta wave begins
Will persist as long as alert

Question 16

Describe Gamma waves?

Answer 16

30-80 Hz
Occur when individual is aroused or focused on something
Replace by even more irregular activity if pan a motor response
May require hippocampus

Question 17

Describe Theta waves

Answer 17

4-7 Hz
100 microvolts
Occurrence
—normal in children, particularly over parietal and frontal cortex
In adults- frustration or disappointment
Also in sleep

Question 18

Describe Delta waves

Answer 18

<3.5 Hz
100-200 microvolts
Occurrence:
—deep sleep in adults
Infants 
Appearance during “wakefulness” sign of serious organic brain disease 
Dissociation of cortex and thalamus

Question 19

What does a EEG in infancy look like?

Answer 19

Fast beta-like activity, but over the occipital region theres is a slow 0.5-2.0 Hz activity

Question 20

______ over the ______ region will gradually increase in frequency through childhood?

Answer 20

The activity over the occipital region

Question 21

Adult alpha-wave pattern will appear during _______?

Answer 21

Adolescence

Question 22

When does alpha rhythm decrease (4)?

Answer 22

Hypoglycemia
Low body temperature
Low adrenal glucocorticoid
High PaCO2

Question 23

_______ cycle of the night last 70-100 minutes then moves in a short ____?

Answer 23

First cycle

Short REM

Question 24

Describe the later sleep cycles?

Answer 24

90 minute cycle length

Less time in deep sleep, more in REM sleep

Question 25

Describe Children sleep cycles?

Answer 25

More time in REM
More time in deep sleep
More total sleep time

Question 26

Describe the elderly’s sleep cycles?

Answer 26

Fewer REM epochs (longer)
Almost no deep sleep
More frequency awakening
Less total sleep (more likely to nap)

Question 27

What are the two classes of sleep?

Answer 27

Slow wave sleep
—stage N1, N2, N3
—characterized by slowing of the EEG

REM Sleep
—rapid eye movement
—dreaming

Question 28

Describe stage 1 of sleep?

Answer 28

Drowsiness/earliest stage of sleep
PHyscial characteristic:
—slow, rolling movement of the eyes
—EMGs show muscle activity

EEG characteristic
—low voltage EEG
—Slowing of Frequency

Question 29

Describe Stage 2 of sleep?

Answer 29

True sleep
Physical characteristics:
—EMGs show Muscle activity, but relatively quiet
EEG:
—Increasing voltage 
—slowing of frequency
—sleep spindles

Question 30

What are sleep spindles?

Answer 30

Begin to appear in N1, most common in N2
Bursts of alpha-like activity interrupting the slower EEG of Sleep
O fern preceded by a sharp wave (K complex)

Question 31

Describe N3 deep sleep?

Answer 31

True sleep
Physical: 
—deep sleep
EEG:
—increasing voltage EEG
—slowing of frequency- theta and delta wave

Question 32

Describe REM Sleep?

Answer 32

Physical:
—rapid side-to-side movement
—EMG becomes very quiet (locus ceruleus suppresses)
—vivid dreams
EEG:
—Rapid, low voltage
—similar to beta waves