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Flashcards in Sleep Deck (24):
1

What methods are used to define sleep stages?

EEG
EOG (electro-oculogram)
EMG of chin muscle tone

additional methods: respiratory effort, oxygenation, ECG, surface EMG

2

What are some key neurotransmitters of waking state?

Histamine (tubomamillary nucleus)
NE (locus ceruleus)
serotonin (raphe nuclei)
acetylcholine (basal forebrain)

3

What are the EEG, EOG, and muscle tone features of waking state?

EEG: Low voltage, high frequency, alpha waves (8-13 hz)
EOG: rapid, blinking
Muscle tone: high

4

What are the EEG, EOG, and muscle tone features of N1 state?

EEG: <50% alpha waves
replaced by theta, (4-7 Hz)
vertex waves
EOG: slow roving eye movements
Muscle tone: high

5

What are the EEG, EOG, and muscle tone features of N2 state?

EEG: vertex K: high voltage positive and negative discharges with spindles (11-16 Hz)
Spindles ~5 seconds
EOG: still
Muscle tone: high

6

What are the EEG, EOG, and muscle tone features of N3/slow wave/ Delta sleep?

EEG: slow wave, high voltage (>75 uV), low frequency (<2Hz)
EOG: still
Muscle tone: low
Reduced BP, HR, cardiac output, RR
GH release

7

What are the EEG, EOG, and muscle tone features of REM sleep?

EEG: mixed frequency, low voltage, sawtooth waves
EOG: RIM
Muscle tone: very low
Cholinergic brain state
irregular respiration
Arrhythmias, heart rate variation
dreaming

8

What is the difference between tonic and phasic REM sleep?

Tonic: impaired thermoregulation, hypotension, bradycardia, increased cerebral blood flow, increased ICP, increased RR, erection, atonia
phasic: vasoconstriction, increased BP, tachycardia, further increase in cerebral blood flow and RR

9

What part of the midbrain is involved in REM sleep?

Pons: REM on/off cells

10

How long is the sleep cycle?

90 minutes

11

how do the characteristics of the 4 stages change through a full night's sleep?

increasing REM time and decreasing N3
1 5%
2 50%
3 20%
REM 25%

12

A lesion in what location causes narcolepsy?

posterior hypothalamus

13

What nucleus's activity is correlated with sleep ONSET?

VLPO (anterior hypothalamus)

14

Does dimlight suppress melatonin?

Yes. Melatonin increases in the evening

15

How many hours do new borns sleep? what percentage is REM?

18 hours, 50%

16

What changes occur to delta sleep with age?

decrease, although this could be an artifact of definitional problem (EEG slows down with age, and leads to the appearance of reduced delta sleep)

17

What's the effect of antihistamines on sleepiness?

increase sleepiness

18

What's the effect of benzodiazepines on sleep?

Reduced delta sleep

19

What's the effect of TCA/SSRI/MAO-I on sleep?

increase RIM latency, reduce REM

20

What are the key markers of circadian rhythm?

cortisol, temperature, REM timing

21

When is cortisol/GH produced?

Cortisol in the morning, with or without sleep
GH only following sleep (N3)

22

Where is the centre of control for circadian rhythms?

Suprachiasmatic nucleus (SCN)

23

What are the afferents for SCN?

retinohypothalamic, lateral geniculate nucleus, raphe nuclei

24

What are the efferents for SCN?

paraventricular nuclei, hypothalamus, thalamus, dorsomedial hypothalamus