sleep REVISE

Question 1

when do babies get a sleep wake cycle of 24 hours?

Answer 1

by around 6 months

REM sleep takes up around 50% of sleep duration

Question 2

what is the role of the SCN?

Answer 2

controls the timing of the sleep wake cycle and co-ordinates it with other circadian rhythms

as well as other functions like attention and body temperature

internal body clock

Question 3

what is the role of melatonin in sleep?

Answer 3

hormone released by the pineal gland into the bloodstream at around 9pm as instructed by the SCN (using environmental cue of light detected by the retino-hypothalamic tract)

induces sleep by regulating the sleep-wake cycle

secretion stops around 7.30am

Question 4

where is the SCN located?

Answer 4

in the anterior hypothalamus

Question 5

what time are we in our deepest sleep?

Answer 5

2am

Question 6

what is the role of cerebral spinal fluid in sleep? as shown by mice?

Answer 6

it is pumped around the brain (10x faster than when awake as brain cells shrinkwhen asleep so space between them 60% greater) and flushes out waste products e.g toxic proteins whose build up can lead to dementia

Question 7

issue with generalisation of brain research on mice to humans?

Answer 7

what happens in a mouse brain might be very different to what happens in more complex human brain as
“sleep in humans has evolved far more sophisticated functions for our cortex than that for the mouse”

might be many other functions of sleep in the human brain due to it’s superior complexity

Question 8

what are the systems benefits of sleep to the body?

Answer 8

restoration of vigilance, learning and cognition

memory consolidation and integration

occurs in REM sleep

Question 9

cellular level benefits of sleep?

Answer 9

restoration of energy, supplies, cellular homeostasis and extracellular space

lack of sleep reduces number of infection fighting antibodies and so is less effective at fighting infectious disases
lack of sleep inhibits wound healing process

occurs in NREM sleep

Question 10

role of the hypothalamus?

Answer 10

arousal level

contains the SCN acting as an internal pacemaker
contains the VLPO which inhibits activity in areas that maintain wakefulness

Question 11

role of the limbic system?

Answer 11

drive and emotional reactivity

Question 12

what is the role of the amygdala?

Answer 12

processing emotions and forms part of the limbic system

Question 13

role of frontal lobe?

Answer 13

assess, plan, inhibit, act (control pannel)

contains Broca’s area in the left frontal gyrus
responsible for language production

Question 14

role of parietal lobe?

Answer 14

sensory actions and visual information

Question 15

role of temporal lobe?

Answer 15

language and memories

contains Wernicke’s area in left temporal gyrus
responsible for comprehension of language

Question 16

role of occipital lobe?

Answer 16

vision

Question 17

what is the cycle of human sleep

Answer 17

90 mins of alternating NREM and REM (25%) sleep

Question 18

what are the 3rd and 4th stages of sleep known as and what occurs in them?

Answer 18

‘slow-wave sleep’
muscles relax and increased blood flow to them
body repairs and energy stores replenished

Question 19

signals of deprived REM sleep?

Answer 19

perceptual distortions, mood impairment, impaired concentration

Question 20

which lobe is inactive during sleep and why?

Answer 20

the frontal lobe as no decisions need to be made

Question 21

which area is active during sleep and why?

Answer 21

the temporal area as it deals with memory

Question 22

what percentage of the average persons dreams are nightmares?

Answer 22

70%

Question 23

names of some sleep disorders

Answer 23

sleep apnea
snoring
narcolepsy
sleepwalking
limb movement disorder

Question 24

psychological causes of sleep problems

Answer 24

other mood disorders:
depression - difficulty waking or getting to sleep and tired in the day
anxiety - frequent waking as alert and awake very early

stress: e.g fears in night

anxiety about sleep

Question 25

health, habits and environmental causes of sleep problems

Answer 25

health : pain / medication
drinks : caffeine, alcohol, need to go to toilet
poor sleep routine: sleeping in day, shift work, surroundings e.g noisy

Question 26

prevalence of insomnia

Answer 26

1 in 9 have nightly insomnia (1999) (Ancoli-Israel and Roth)

Question 27

strategies for better sleep?

Answer 27

put the day to rest
block thoughts - counting backwards
relaxation - breathing and imagery
challenge negative thinking
don't watch the clock

Question 28

what is the associated between sleep disorders and mood/mental health disorders?
and why?

Answer 28

bi-directional

e.g anxiety may cause sleep disorder as alert at night but lack of sleep may cause anxiety

Question 29

what is primary insomnia?

Answer 29

difficulty initiating or maintaining sleep or nonrestorative sleep for at least 1 month (4 nights a week)

Question 30

how long does caffeine take to get out of our system?

Answer 30

6 hours

Question 31

how did Freud describe dreams?

Answer 31

“royal road to unconscious”

Question 32

what is the purpose of dreams?

Answer 32

to keep fight or flight system awake but keep yourself asleep
keep you entertained during you sleep so you don’t wake up (as shown by people who can’t have dreams e.g certain stroke victims keep waking up in the night)

Question 33

primary treatment for sleep disorders?

and how it addresses the sleep problems?

Answer 33

CBT

identify thoughts and behaviours which may worsen sleep and chnage them so that they promote sound sleep instead

Question 34

why is resting with your eyes closed not quite as good for the brain and body as sleep?

Answer 34

some neurons are still active when resting

whereas in some periods of sleep all neurons are completely inactive

Question 35

what state is the body in during REM sleep?

Answer 35

muscles paralysed (atonia) to prevent injury from acting out our dreams
HR near waking level
fast irregular breathing
increased oxygen consumption by the brain

Question 36

characteristics of 1st stage of NREM sleep?

Answer 36

between being awake and asleep

or in very light sleep

Question 37

characteristics of 2nd stage of NREM sleep?

Answer 37

slightly deeper sleep than stage 1

body temperature drops and HR slows down