states of consciousness

Question 1

the Nyquist principle in EEG says that…

Answer 1

the sampling rate must be twice the rate of the fastest rate of interest. Normally it is set 10 times faster

Question 2

what is normal eeg sampling speed

Answer 2

512 mh

Question 3

which are the important type of neurones to remember in the cortex? Which layer

Answer 3

pyramidal, layer 5

Question 4

what is EEG amplitude

Answer 4

0.02-0.1 milivaults

Question 5

what are the eeg scalp locatiosn known as

Answer 5

derivations

Question 6

what do EEGs specifically show and not show

Answer 6

do show ESPS and ISPS summation
do not show action potentials

Question 7

when is eeg sychnonised/desynchronised

Answer 7

sleep/wakefulness(also REM sleep)

Question 8

difference between eyes open and closed awake on eeg

Answer 8

open very desynchronised, closed slightly more synch

Question 9

describe the different waves of sleep and wakefulnes

Answer 9

alpha - awake, eyes closed
beta - active wakefulness/REM sleep
gamma - information processing
theta - sleep/meditation
delta - deep sleep

Question 10

stage 2 sleep has two hallmarks. what are they?

Answer 10

Question 11

what keeps us awake

Answer 11

reticular formation

Question 12

which are the 3 families of NTs in the reticular formation. what nuceli

Answer 12

locus coeruleus - noradrenaline
raphe - seratonin
pedunculopontine - ACH

Question 13

of the 3 types of NTs in the reticular formation, which are active/inactive in wakefulness/sleep

Answer 13

noradrenaline: active awake, less active asleep
Seratonin- atcive awake, more inactive asleep ->totaly inactive in REM sleep
ACH - spontaneously active awake, less active asleep but fully active in REM

Question 14

which cholinergic input creates dreams in REM sleep

Answer 14

basal nucleus of Meynert

Question 15

which structure “turns off” the RF to induce sleep

Answer 15

hypothalamus

Question 16

Which type of brainstem neurons are active in REM sleep at the same rate as in wakefulness?

Answer 16

cholinergic

Question 17

Which of the following symptoms result from anterior hypothalamic lesions?

Answer 17

insomnia

Question 18

which genes, controlled by teh suprachiasmatic nucleus are expressed in a circadian rhythm

Answer 18

CLOCK
BMAL1

Question 19

melatonin is secreted by the

Answer 19

pineal gland

Question 20

what does the suprachiasmatic nucleus respond to and what does it do

Answer 20

sunlight
entrains the cells of the body by triggering release of melatonin as to when it is day and night

Question 21

which two hormones have an inverse relationship across the circadian cycle

Answer 21

cortisol and melatonin

Question 22

caffeine is an antagonst of

Answer 22

adenosine

Question 23

adenosine is increased
when

Answer 23

high cellular workload, increased oxygen consumption

Question 24

which antihistamines cause somnolence

Answer 24

H1 antagonist (diphenhydramine)

Question 25

which nucleus of the hypothalamus releases histamine and why

Answer 25

tuberomamillary increase wakefulness

Question 26

where are the oresin neurones

Answer 26

lateral hypothalamus

Question 27

where is GABA produced in the hypothalamus to promote sleepfulness

Answer 27

preoptic nucleus

Question 28

Answer 28

Question 29

In which state of awareness is growing hormone mostly secreted?

Answer 29

slow wave sleep

Question 30

melatonin is also a scavenger of..

Answer 30

free radicals

Question 31

The extracellular space of the brain expands how much durin sleep. Why?

Answer 31

60 % during sleep, facilitating exchange between the interstitial fluid and the cerebrospinal fluid.