Sleep Phys and Disorders Flashcards Preview

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Flashcards in Sleep Phys and Disorders Deck (50):
1

What part of the brain, in very general terms, regulates sleep?

diencephalic nuclei

2

See slide 5 for ambient light summary

ok

3

Body temperature does what during sleep periods?

Falls

4

Growth hormone is released most when?

Just after we fall asleep

5

Cortisol is released most when

Just before we wake up

6

Method of measuring sleep is known as

polysomnography

7

How many stages of sleep are there

5

8

What are the different divisions of EEG frequency

Beta- Over 13 hz
Alpha- 8-13 hz
Theta- 4-7 hz
D- less than 4

9

Beta frequency EEG

Over 13 hz. Most commonly seen in normal awake human beings

10

As frequency falls, what happens to ampltude>

It rises

11

So, basically as you progress from "Awake" through stage 4, the frequency of the EEG falls while the amplitude of the waves rise.

ok

12

What is unique about the EEG in REM sleep?

It is appears to be very similar to that of the awake sleep

13

Stages I-IV together are called

Non- REM sleep

14

Stage I is the lightest sleep and stage 4 is the...

deepest

15

Sleep spindles and K complexes are characteristics of what stage of sleep

2

16

What type of EEG activity characterizes stage I and II of sleep?

Theta

17

Stage 3 and 4 sleep are characterized by what kinds of EEG waves

Delta

18

The duration of sleep in stages 3 and 4 is longest when?

Early in a sleep cycle

19

The duration of REM sleep is longest when>

Late in the sleep cycle

20

Compare Non-REM with REM. Physiologically

NREM- Eye movements are slow, movement occurs but muscle tone is decreased
- Decreased BP, HR, RR, metabolic rate
- Dreams less vivid, low emotional content
- Sleep walking and night terrors occur during slow wave
- All reach a maximum during Stage IV sleep


REM-
- Rapid eye movements
- muscle paralysis
- HR, BP, RR, temp and metabolism approach awake level
- Dreams Vivid, high emotional content

21

Penile and clitoral erection occur when?

During REM sleep

22

Brain activity is increased where during REM sleep?

_ Amygdala, parahippocampal gyrus, anterior cingulate cortex

23

What brain areas are inhibited during REM

- Frontal Cortex and posterior Cingulate cortex.

24

What is the significance of these active and inactive brain regions

- The activity explains the vivid, emotional dreams that occur during REM.
- The inhibition of the certain brain regions may explain the bizarre nature of some dreams due to reduced executive reasoning and ratinal thought

25

Make a chart for the Neural sleep circuits

ok

26

The Neural sleep Circuit that is Cholinergic in nature is

- Cholinergic neurons from the pedunculopontine (PPT) and Lateral Dorsal Tegmental (LDT) project to the thalamus and other brainstem areas.

- Triggers thalamic cortical signaling that produces high frequency, low voltage EEG activity consistent with arousal.

- Also active during REM sleep

27

Noradrenergic sleep circuit?

Noradrenergic input comes from the locus ceruleus to the neocortex

Highly activated during wakefullness, none during REM

28

Dopaminergic wakefullness cicuits originate where?

Substantia Nigra

This circuit is most important for full wakefullness

29

Serotonergic circuits originate where?

dorsal and medial raphe nuclei

30

Histaminergic output during wakefulness comes from

tuberomammillary nucleus

31

What is important about the Orexin pathway

90% of pts with narcolepsy have significantly decreased or undetectable levels of orexin

32

Ventrolateral preoptic nucleus

Significant because it harbors GABAergic and Galanin neurons both of which innervate and inhibit all of the nuclei that activate arousal. Thus, activation of the VLPO causes decreased forebrain arousal and the onset of NREM sleep

33

Lesions of the VLPO would lead to

insomnia

34

What are somnogens

endogenous sleep- promoting chemicals that may accumulate during wakefulness and promote sleep onset.

35

Adenosine

a somnogen that builds up in the CNS during wakefullness and declines during sleep

36

Cytokines IL-1B and TNF

promote sleep

37

Melatonin

synthesis turned on by decreasing light

38

Multiple sleep latency test

EEG defined sleep latency, i.e, the time required to fall asleep during 4-5 daytime naps

39

Epworth sleepiness sclae

self-reported tendency to fall asleep in 8 diff situations

40

Obstructive Sleep Apnea

Repetitive blockage of the resp pathway during sleep causing apneic periods lasting
- Longer than 10 senconds
- and causing oxyhemoglobin desaturations of more than 4%

41

Strong association b/w OSA and

heart disease and HTN

42

Check out OSA phys findings and symptoms slide

- May have:
Nasal obstruction
Tonsillary hypertrophy
HTN
CHF
Pitting Edema with large hands and feet

Snoring, heartburn, memory loss, depression, nocturia, impotnece

43

Narcolepsy

Excessive daytime sleepiness associated with one or more of the following tetrad:
- sleep attacks/ intrusions
- cataplexy- abrupt loss of muscle tone
- sleep paralysis- persistent REM sleep atonia after waking
- hypnagogic hallucinations

44

90% of ppl with narcolepsy develop it when

by 2nd or 3rd decade

45

Pathogenesis of Narcolepsy

loss of hypocretin/orexin secreting neurons in the posterior lateral hypothalamus

- related to HLA genes DQ1 and DQB1 that may predispose to autoimmune attack on orexin secreting neurons

46

Dx of narcolepsy

- clinical pres
- Low CSF hypocretin level

47

REM sleep behavior disorder

- Loss of atonia/paralysis during REM sleep.
- Very rare, most common in adult males over 50

See slide for pathogenesis info

48

Melatonin produced where

Pineal Gland

49

Sleep Cycle Stage Progression

Awake- stage 1 - stage 2- stage 3- stage 4
Back to 3, 2, 1 etcc... periodically moving into REM

50

one sleep cycle =

begins at stage one and ends with a period of REM....takes about 90 minutes