normal sleep cycle

Question 1

what are the stages of sleep and how long do we approximately spend in each?

Answer 1

stage 1 ( 6%)
stage 2 ( 49%)
stage 3 and 4 ( 23%)
REM ( 22%)

Question 2

how long do we typically cycle through a sleep cycle?

Answer 2

~90 minutes

Question 3

what happens to REM as we we progress in our sleep?

Answer 3

time spent in REM increases as the hours of sleep progress

Question 4

which stage of sleep lessens ( i.e. the amount of time spent in that stage) as the hours of sleep progress?

Answer 4

stage 4

Question 5

what are the light stages of sleep and what are the deep sleep stages?

Answer 5

light sleep stages: 1 and 2

deep sleep stages are: 3 and 4

Question 6

what does brain activity look like in the REM cycle?

Answer 6

it looks like we are awake

Question 7

*** what types of waves on EEG are associated w/ alertness?

Answer 7

low voltage, fast, random activity high frequency BETA waves ( 15-40 cps)

Question 8

***what types of waves EEG are associated w/ being awake but drowsy/relaxed?

Answer 8

low voltage, fast, random activity high frequency ALPHA waves ( 8-13 cps)

Question 9

*** what types of waves on EEG are associated w/ stage 1 sleep ( the lightest sleep)?

Answer 9

low voltage, high frequency, THETA waves ( 3-7 cps)

Question 10

*** what types of waves on EEG are associated w/ stage 2 sleep ( the light sleep)?

Answer 10

SLEEP SPINDLES AND K COMPLEXES

Question 11

*** what types of waves on EEG are associated w/ stage 3 sleep ( deep sleep)?

Answer 11

< 50% DELTA waves

Question 12

*** what types of waves on EEG are associated w/ stage 4 sleep ( deepest sleep)?

Answer 12

> 50 % DELTA waves

parasympathetic control, lowered vital signs, restorative sleep

Question 13

*** what types of waves on EEG are associated w/ REM?

Answer 13

low, voltage, high frequency, random, fast waves w/ SAWTOOTH waves

Question 14

what is the reason for the brain being more awake in REM?

Answer 14

the increase in sympathetic tone dominating

Question 15

what actions occur during REM?

Answer 15

eye movements, erections, dreams, and paralysis

Question 16

what are dreams?

Answer 16

unconscious thoughts, drives, wishes,
consolidation of memory rom the day
removing unwanted memory from the day

Question 17

what stages of sleep decrease in the elderly and which increase?

Answer 17

stages 3 and 4 decrease in the elderly and stages 1 and 2 increase in the elderly

Question 18

sleep length generally decreases until what age and then maintains a generally stable length?

Answer 18

20 years old

Question 19

what is the signal to go to sleep?

Answer 19

melatonin

Question 20

where and when and why is melatonin produced?

Answer 20

in the pineal gland at night because there is a loss of light which induced neuronal firing in the retinohypothalmic tract which helps lower brain activation and arousal

Question 21

what does melatonin do to sympathetic drive?

Answer 21

it lowers sympathetic drive

Question 22

when does cortisol peak and why is this important?

Answer 22

it peaks in the morning ( around 4-5) and this is important because it is the signal to wake up and it links the hypothalamic-pituitary-adrenal cortex to the circadian system

Question 23

which 6 neurotransmitters result in more wakefulness ( more of them = more wakefulness and less of them = more asleep)

Answer 23

acetylcholine, glutamate,

monoamines: norepinephrine, dopamine, serotonin, histamine

Question 24

how do neurotransmitters that result in more wakefulness act on the brain?

Answer 24

directly in certain areas and modulate other transmitters’ effects as well as allowing amplification of arousal signals.

Question 25

the basal forebrain releases what neurotransmitter and what it this driving?

Answer 25

Ach, this drives person to be awake or in REM

Question 26

The basal forebrain is active during?

Answer 26

wakefulness and REM

Question 27

Besides Ach what does the basal forebrain release?

Answer 27

GABA which promotes sleep in sleep centers

Question 28

the laterodorsal and pedunculopontine tegmental nuclei are more likely to be active during?

Answer 28

wakefulness and REM

Question 29

how is wakefulness most robustly promoted?

Answer 29

via projections to the thalamus

Question 30

Ach from what two main centers activate the brain to keep ppl awake at appropriate times?

Answer 30

the pontine nuclei: lateral dorsal and pedunculopontien tegmental nuclei and the basal forebrain

Question 31

related to sleep why would someone be given norepinephrine?

Answer 31

to increase wakefuleness

Question 32

what does the locus coreleus do?

Answer 32

release norepi

Question 33

insomnia or anxiety at night could be due to ?

Answer 33

too much norepi firing

Question 34

what is norepi inhibited by in the feedback loop?

Answer 34

alpha 1 and 2 receptors in the feedback loop

Question 35

in relation to sleep what can blood pressure medications be used for?

Answer 35

to lessen nightmares and anxiety

Question 36

*** what does stimulation of H1 receptors do?

Answer 36

leads to wakefulness

Question 37

what do h3 autoreceptors do?

Answer 37

inhibit histamine activity thus blocking H3 receptors therefore promoting wakefulness.

Question 38

***you can be awake by stimulating which histamine receptor and blocking which histamine receptor?

Answer 38

you can be awake by stimulating the H1 receptor and by blocking the H3 receptor

Question 39

what does the tuberomammilary nucleus in the posterior hypothalamus do?

Answer 39

secrete histamine

Question 40

serotonin can increase or decrease sleep depending on sensitivity for receptors but what does it generally do?

Answer 40

serotonin generally increases wakefulness and inhibits REM

Question 41

***what does the 5HT7 receptor do?

Answer 41

it is the circadian clock gene i promotes and corrects circadian rhythms (it comes from the raphe nucleus)

Question 42

what is dopamine associated w/ ?

Answer 42

movement( release from substantia nigra) and reward ( release from ventral tegmental area) ( sex, drugs, rock and roll)

Question 43

ppl who are tired or have ADHD have how much dopamine?

Answer 43

low dopamine

Question 44

the ventral periaqueductal gray in the pons fires during?

Answer 44

wakefulness and is associated with dopamine

Question 45

what type of arousal does dopamine provide in comparison to norepi?

Answer 45

dopamine provides motivational arousal whereas norepi provides task oriented alertness

Question 46

how is orexin/hypocretin like a back up generator?

Answer 46

it is not a part of the reticular activating system and therefore keeps other systems going and increases wakefulness if other systems fail.

Question 47

when does orexin/hypocretin fire?

Answer 47

only when you are awake

Question 48

where do the stage 2 sleep spindles probably come from?

Answer 48

the thalamus

Question 49

the thalamus uses glutamate to promote ?

Answer 49

wakefulness

Question 50

the thalmus uses GABA to ?

Answer 50

decrease wakefulness and promote sleep

Question 51

what is the master switch in the anatomy of being awake?

Answer 51

the suprachiasmatic nucleus

Question 52

what does the reticular activating system include?

Answer 52

ach, serotonin, norepi, dopamine

Question 53

what does the reticular activating system do?

Answer 53

drives us to be awake when turned up high or towards fatigue if low.

Question 54

can the reticular activating system be manipulated?

Answer 54

yes

Question 55

for PTSD pts what is the level the reticular activating system is likely to be at?

Answer 55

> 120% ( towards wakefulness)

Question 56

**** what happens if you don't have the orexin/hypocretin?

Answer 56

narcolepsy