Physiology of sleep

Question 1

Characteristics of NREM sleep

Phases

shape of sleep waves

arousal threshold, muscle activity compared to awake

type of eye movements

Answer 1

N1, N2, N3 (slow wave sleep

high amplitude, slow waves

incr arousal threshold, decr muscle activity

slow rolling eye movements

Question 2

Characteristics of NREM

HR, resp, metab

when does it occur in sleep

Answer 2

decr HR, resp, metab

early in sleep

Question 3

when do disorders of arousal occur during sleep

Answer 3

walking, terrors, night eating during N3 slow wave sleep

Question 4

Characteristics of REM

type of eye movements

lasts how long

what does EEG look like

compare arousal threshold, muscle activity to NREM

Answer 4

rapid eye movements

approx 90 min

EEG looks like awake

incr arousal threshold compared to NREM
muscles paralyzed except eyes, mid ear, diaphragm

Question 5

Characteristics of REM

temp regulation

clitoris and penis

HR, resp

Answer 5

suspended temp regul
brain temp incr

incr clit and penis

irregul HR, resp

Question 6

when do most reconciliable dreams occur

Answer 6

REM

Question 7

what stage of sleep occurs late in sleep during early morning hours

Answer 7

REM sleep

Question 8

describe interaction of circadian (process C) and homeostatic system (process S) and effect on wake and on sleep

Answer 8

Process C operates independent of both behavior and light input (when and how often you sleep)

if light appropriate, it reinforces C rhythm

homeostatic process S that contirbute to feeling sleepy

PRESSURE FROM BOTH C AND S THAT CONTRIBUTE TO FEELING SLEEPY –> changes core body temp

Question 9

sleep effect on NT

Answer 9

over course of day, you decr NT and you need sleep to get all NT back to normal

Question 10

you are best able to sleep when ___

and most alert when ___

Answer 10

best sleep = core temp lowest

most alert = body temp greatest

Question 11

pedunculopontine tegmental = caudal to substantia nigra

1) REM-on/wake-on neurons

1) NT involved?
2) when is it active

Answer 11

1) ACh

2) active in Wake and very active REM

Question 12

pedunculopontine tegmental = caudal to substantia nigra

1) REM-on neurons

1) NT involved?
2) when is it active

Answer 12

1) ACh

2) active in REM

Question 13

Dorsal raphe

1) NT involved?
2) when is it active

Answer 13

1) serotonin

2) active = wake
reduced = NREM

Question 14

Locus ceruleus

1) NT involved?
2) when is it active

Answer 14

1) NE

2) active = wake
reduced = NREM

Question 15

tubulomammillary posterior hypothal

1) NT involved?
2) when is it active

Answer 15

1) histamine

2) active = Wake

Question 16

ventral lateral pre-optic anterior hypothal

1) NT involved?
2) when is it active

Answer 16

1) GABA, galanine

2) active = NREM
reduced = REM

Question 17

VTA and subst nigra

1) NT involved?
2) when is it active

Answer 17

1) dopamine

2) active = wake, REM

Question 18

basal forebrain

1) NT involved?
2) when is it active

Answer 18

1) adenosine

2) incr in wake
decr in NREM

Question 19

lateral hypothal

1) NT involved?
2) when is it active

Answer 19

1) hypocretin

2) active = wake
some active = REM

Question 20

which neurons are important in driving REM sleep

Answer 20

cholinergic nuclei of brain stem (PPT neurons)

Question 21

what is important for sleep initiation

Answer 21

VLPO of anterior hypothal (GABA/galanine)

Question 22

what is disturbed in narcolpesy

Answer 22

lateral hypothal (hypocretin)

Question 23

what causes homeostatic pressure to incr during wake?

Answer 23

accum adenosine

Question 24

sleep/wake cycle governed by

Answer 24

interaction btwn homeostasis (S) and circadian rhythm (C system)

Question 25

NREM and slow wave (N3) occurs ___ in sleep and REM peaks ___

Answer 25

NREM = early sleep
REM = early morning

Question 26

short REM latency seen in ___

Answer 26

depression
alcohol withdrawal
narcolepsy
OSA

Question 27

SCN importance in sleep

Answer 27

receive light from retina to control sleep wake

Question 28

hypothal importance in sleep

Answer 28

contains GABA, histamine, hypocretin nuceli for wakefulness and sleep patterns

Question 29

thalamus importance in sleep

Answer 29

closed by GABA and galanin to generate sleep spindles in sleep initiation

Question 30

brainstem importance in sleep

Answer 30

has aminergic (REM-off) and cholinergic (REM-on) neurons to thal and cortex for sleep patterns

cholinergic neurons open thal to wake us up

Question 31

role of light in sleep patterns

Answer 31

1) light enters eye
2) travel to SCN
3) pineal gland
4) superior cervical ganglion
5) inhib melatonin

Question 32

compensation following sleep loss =

Answer 32

homeostatic drive to sleep likely due to adenosine buildup