Sleep

Question 1

polysomnogram

Answer 1

EEG- brain activity
EOG- eye movement
EMG- reflects muscle tone
EKG- reflects cardiac impulse conduction
respiratory channels

Question 2

brain waves

Answer 2

delta 30 Hz

Question 3

three primary brain states

Answer 3

awake- low voltage, fast EEG

sleep- NREM- high voltage, slow EEG

REM- low voltage, fast EEG

Question 4

wake

Answer 4

alpha rhythm- best seen in occipital regions (defined as with eyes closed)

rapid eye movements

normal muscle tone

Question 5

non-rem

Answer 5

N1- light sleep
N2
N3- deep sleep/ slow wave sleep/ delta sleep

Question 6

N1

Answer 6

alpha drop out- theta replaces it
vertex sharp waves
slow eye movements
muscle relaxation
sleep starts- full body jerk
central apneas

Question 7

N2

Answer 7

theta movement- progressive sllowing
eye movement stops
sleep spindles- 12-14 Hz
K complex- large amplitude bi phasic evoked response

Question 8

N3

Answer 8

> 20% slow wave activity

frequency and amplitude- .5-2 Hz slow wave activity
high amplitude

hard to wake from

no eye movements

Question 9

night terrors come from N3

Answer 9

ok

Question 10

REM

Answer 10

reticular activation- desynchronization
stage 1 like EEG- sawtooth wavs
hippocampal theta activity
phasic/tonic components
rapid eye movements

muscle atonia
muscle twitches
cognitive activity

Question 11

which stages dominate which parts of the night

Answer 11

N3 dominates first 1/3

REM dominates in the last 1/3

Question 12

how much time do we spend in each sleep stage

Answer 12

N1 5%
N2 50%
N3- 20%
REM- 25%

Question 13

compare and contrast non rem and rem sleep

Answer 13

nonREM- decreased HR and BP, decreased drive to low O2 and increased CO2, intact thermal regulatoin, reduced muscle tone, decreased CBF, reduced cognitive function

REM- variable sympathetic activity, lowest drive to low O2 and increased CO2, no thermal regulation, minimal muscle tone, increased genital blood flow, increased CBF, abundant, bizzare cognitive function

Question 14

how does sleep change w/ age

Answer 14

fetus- 80% active sleep (REM)
newborn- 16-18 hrs. 50% is active
3-4 months- establishment of nocturnal period
1 yr- 12-13 hrs sleep, 30% REM
2 years- 10 hrs sleep, 25% REM

second decade- marked decline in slow wave activity. continues to decrease across life

REM stays constant

elderly- sleep less, nap more, lighter sleep and increased awakening

Question 15

zeitgebers

Answer 15

external cues that regulate circadian rhythm

Question 16

entrainment

Answer 16

describes period and phase control of an oscillator by an environmental cycle

-adjustment of internal cycle to external cycle, and synchronization of various internal clocks

Question 17

free running

Answer 17

persistence of rhythms during constant conditions

current evidence suggests pacemaker period is 24.2 hrs

Question 18

photic entrainment

Answer 18

light entrains the circadain rhythm

graphic description of cycles in response to light is a phase response curve

light near initiation of dark cycle produces phase delay

light near conclusion of dark activity produces phase advance

Question 19

what is responsible for humans circadian rhythm

Answer 19

suprachiasmatic nucleus in hypothalamus

keeps cycle in isolation

some rhythms persist after SCN removal

Question 20

rhythmicity evident in what cycles?

Answer 20

temp, hormones, CV

Question 21

melatonin

Answer 21

released by pineal gland in response to darkness, reinforces darkness signal at SCN
linked to control of body temp

levels decline from childhood onwards

acts as a phase shifter and sleep promotor

Question 22

delayed sleep phase type

Answer 22

delayed sleep phase,

inability to fall asleep at approriate time, but otherwise healthy sleep

commonly seen in younger individuals

causes: endogenous rhythm, exposure to light in evening, lack of exposure to morning light, depression, behavior preference

treatment- chronotherapy- three hour progressive delay phase or thirty minute progressive phase advance

Question 23

process s

Answer 23

homeostatic drive to sleep- related to sleeping and waking

“something” is accumulating while you were awake

exponential rise during wake, declines during sleep

correlated w/ slow wave sleep

probably adenosine driven

Question 24

process c

Answer 24

circadian rhythm- variation of sleep tendency based on temporal schedule

Question 25

adenosine

Answer 25

inhibits basal forebrain ACh neurons

high concentrations in wake

declining concentrations in SWS

caffeine is adenosine antagonist

Question 26

where is NE secreted from?

Answer 26

locus coeruleus

Question 27

where is serotonin secreted from?

Answer 27

dorsal raphe

Question 28

where is ACh secreted from?

Answer 28

PPT/LDT (brainstem) and basal forebrain

Question 29

where is histamine secreted from?

Answer 29

hypothalamus- tuberomamillary nucleus

Question 30

where is adenosine secreted from?

Answer 30

basal forebrain, hypothalamus

Question 31

where is orexin/hypocretein secreted from?

Answer 31

hypothalamus

Question 32

where is DA secreted from?

Answer 32

brainstem/ hypothalamus

Question 33

RAS

Answer 33

project to thalamus, basal forebrain, cortex, and hypothalamus

produce desynchronization of cortical neurons- wakefulness

LDT, locus coeruleus, raphe, and tuberomamillary bodies promote wake

Question 34

orexin/hypocretin

Answer 34

wake active- may prevent unwanted transitions to sleep

projections to cortex and ARAS

Question 35

sleep active

Answer 35

VLPO- acts on wake promoting areas in inhibitory fasion

also inhibits orexin, switching to sleep

switch flips w/ buildup of adenosine

Question 36

REM sleep generation

Answer 36

decreased firing in locus coeruleus, tuberomamillary bodies and raphae neurons

increased firing in LDT and PPT (ACh)- wake centers

descending motor inhibition

Question 37

sleep function

Answer 37

restoration
energy conservation
memory function
promotion of CNS in young
maintenance of circuitry
restoration of NTs