chronobiology (27)

Question 1

list the percent of time spent in each of the stages of sleep
stage 1
stage 2
stage 3&4
REM sleep

Answer 1

stage 1: 6%
stage 2: 49%
stage 3&4: 23%
REM sleep: 22%

Question 2

how many minutes is each cycle? what is the cycle order?

Answer 2

90 minutes

1-2-3-4-3-2-REM

Question 3

through out the night, describe what happens to the duration of REM and stage 4 sleep?

Answer 3

REM amount increases throughout the night

stage 4 sleep decreases throughout the night

Question 4

what type of waves are present in the alert stage?

Answer 4

beta waves

Question 5

what type of waves are present in the awake stage?

Answer 5

alpha waves

Question 6

describe the awake stage (compared to the alert stage

Answer 6

“awake stage” is you are awake but drowsy/relaxed

Question 7

what type of waves are present in stage 1?

Answer 7

theta waves

Question 8

what stage is considered your lightest sleep?

Answer 8

stage 1

Question 9

what type of waves are present in stage 2?

Answer 9

sleep spindles & K complexes

Question 10

what type of waves are present in stage 3?

Answer 10

delta waves

Question 11

what stage does this describe?

“ deep slow wave sleep”

Answer 11

stage 3

Question 12

what type of waves are present in stage 4?

Answer 12

delta waves

Question 13

explain what is occurring in stage 4 sleep

Answer 13

parasymp control, lowered viral signs, restorative sleep

Question 14

what type of wave is characteristic of REM?

Answer 14

low voltage fast activity (similar to stage 1) or sawtooth pattern

Question 15

what stages of sleep decrease with age?

Answer 15

stages 3 and 4

Question 16

what stages increase with age?

Answer 16

1 and 2

Question 17

where is the melatonin produced?

Answer 17

pineal gland at night

Question 18

what is melatonin produced in response to?

Answer 18

in response to light induced neuronal firing in the retinohypothalamic tract

Question 19

what receptor is involved in the lowering of brain activation & arousal?

Answer 19

M1

Question 20

what receptor facilitates the 24 hour circadian clock?

Answer 20

M2 receptors

Question 21

what does melatonin do to the sympathetic drive?

Answer 21

suppresses it

Question 22

when does cortisol peak?

Answer 22

in the morning

Question 23

where is ACh secreted from?

Answer 23

basal forebrain

Question 24

what does the GABA secreted from the basal forebrain do?

Answer 24

it inhibits inhibitory neurons in sleep promoting centers to decrease the sleep drive

Question 25

where is norepi secreted from?

Answer 25

the locus coeruleus

Question 26

is norepi fired during NREM & REM sleep?

Answer 26

yes but not nearly as much as during wakefulness

Question 27

what can excessive firing of noepi cause?

Answer 27

it can cause insomnia & anxiety at night

Question 28

what structure secretes histamine?

Answer 28

tuberomammilary nucleus in the posterior hypothalamus

Question 29

is histamine secreted during sleep?

Answer 29

yes just not as much as when awake

Question 30

what happens when you stimulate H1 receptors?

Answer 30

wakefulness

Question 31

what happens when you stimulate H3 autoreceptors?

Answer 31

histiamine is inhibited

so you have to block H3 if you want wakefulness

Question 32

what structure secretes serotonin?

Answer 32

the dorsal raphe

Question 33

what is the action of serotonin?

Answer 33

generally promotes wakefulness & inhibits REM

Question 34

where is dopamine produced?

Answer 34

in the substantia nigra and ventral tegmental area

Question 35

what neurotransmitter does this describe:

“may provide motivational arousal as opposed to task oriented alertness”

Answer 35

dopamine

Question 36

what is special about the orexin/hypocretin system?

Answer 36

it is NOT part of the RAS system

it is part of its own system important in keeping the other systems going

Question 37

does orexin/hypocretin system fire when you are asleep?

Answer 37

NO, only fire when awake