states of consciousness Flashcards
the Nyquist principle in EEG says that…
the sampling rate must be twice the rate of the fastest rate of interest. Normally it is set 10 times faster
what is normal eeg sampling speed
512 mh
which are the important type of neurones to remember in the cortex? Which layer
pyramidal, layer 5
what is EEG amplitude
0.02-0.1 milivaults
what are the eeg scalp locatiosn known as
derivations
what do EEGs specifically show and not show
do show ESPS and ISPS summation
do not show action potentials
when is eeg sychnonised/desynchronised
sleep/wakefulness(also REM sleep)
difference between eyes open and closed awake on eeg
open very desynchronised, closed slightly more synch
describe the different waves of sleep and wakefulnes
alpha - awake, eyes closed
beta - active wakefulness/REM sleep
gamma - information processing
theta - sleep/meditation
delta - deep sleep
stage 2 sleep has two hallmarks. what are they?
what keeps us awake
reticular formation
which are the 3 families of NTs in the reticular formation. what nuceli
locus coeruleus - noradrenaline
raphe - seratonin
pedunculopontine - ACH
of the 3 types of NTs in the reticular formation, which are active/inactive in wakefulness/sleep
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
which cholinergic input creates dreams in REM sleep
basal nucleus of Meynert
which structure “turns off” the RF to induce sleep
hypothalamus
Which type of brainstem neurons are active in REM sleep at the same rate as in wakefulness?
cholinergic
Which of the following symptoms result from anterior hypothalamic lesions?
insomnia
which genes, controlled by teh suprachiasmatic nucleus are expressed in a circadian rhythm
CLOCK
BMAL1
melatonin is secreted by the
pineal gland
what does the suprachiasmatic nucleus respond to and what does it do
sunlight
entrains the cells of the body by triggering release of melatonin as to when it is day and night
which two hormones have an inverse relationship across the circadian cycle
cortisol and melatonin
caffeine is an antagonst of
adenosine
adenosine is increased
when
high cellular workload, increased oxygen consumption
which antihistamines cause somnolence
H1 antagonist (diphenhydramine)
which nucleus of the hypothalamus releases histamine and why
tuberomamillary
increase wakefulness
where are the oresin neurones
lateral hypothalamus
where is GABA produced in the hypothalamus to promote sleepfulness
preoptic nucleus
In which state of awareness is growing hormone mostly secreted?
slow wave sleep
melatonin is also a scavenger of..
free radicals
The extracellular space of the brain expands how much durin sleep. Why?
60 % during sleep, facilitating exchange between the interstitial fluid and the cerebrospinal fluid.
