BMS11004 - WEEK 6 WEDNESDAY

Question 1

overview sleep

Answer 1

complex behavioural programme associated with drastic changes in behavioural and brain activities, and change in gene expression

Question 2

define sleep behaviourally

Answer 2

reduced motor activity and stimulus response, stereotypic posture, relatively easy reversibility

Question 3

name 3 physiological measures for sleep

Answer 3

electromyography
electro oculography
EEG

Question 4

what does EEG record

Answer 4

measuring synchronous electrical activity from large neuron groups, created by cellular ionic movements, creating electrical field

Question 5

give advantages of EEG

Answer 5

non-invasive, data easy, high temporal res-measure activity change in milliseconds

Question 6

give disadvantages of EEG

Answer 6

low spatial res, electric field follow inverse square law so only cortical activity detectable (further away electrode is from activities source means smaller signal)

Question 7

what Hz is alpha wave?

Answer 7

8-13Hz

Question 8

what Hz is beta wave?

Answer 8

13-30Hz

Question 9

how much of sleep is in REM/or not

Answer 9

75% non rem, 25% rem

Question 10

name first 4 sleep stages - non REM

Answer 10

drowsiness (few min)
light sleep (5-15min)
deep sleep
very deep sleep

Question 11

sleep stage 1 - explain drowsiness

Answer 11

easily reversible, slow eyes, muscle activity, muscle contracting (falling sensations)
low-voltage activity EEG (mostly theta waves)

Question 12

sleep stage 2 - explain light sleep

Answer 12

eye movement stop, brain wave slow (occasional burst of rapid brain waves)
body temp, HR drop
EEG sinusoidal waves “sleep spindles” (12-14Hz), biphasic waves “K complexes” (occur episodically alongside low voltage activity)

Question 13

sleep stage 3 - explain deep sleep

Answer 13

high amplitude, very slow delta waves (0.5-2Hz), interspersed with smaller fast wave
sleepwalking, night terror, talk, wetting bed
parasomnia (during transition between non/REM)

Question 14

sleep stage 4 - explain very deep sleep

Answer 14

brain produce mostly delta waves
disorientation for several min after wake
slow wave activity increases

Question 15

sleep stage 5 - explain REM

Answer 15

mimic awake EEG (low voltage, mixed frequency)
rapid eye movements, relating to intense dreams
paradoxical sleep (neuron firing similar to when awake)
brain temp, metabolic rates increase
atonic skeletal muscle (flaccid, paralysis)
eye, middle ear ossicles, diaphragm muscles active to hear impending danger

Question 16

explain a normal sleeping pattern

Answer 16

stages 1-4 non-REM, stage 5-REM
70-80min returns to stage 2/3 then enter first REM (8-10min)
firstnon REM-end of REM = 90-110min
4/5x per night

Question 17

explain sleep patterns in young adults

Answer 17

5% in stage 1
most amount stage 2(50-60%)
stage 3/4 (15-20%)
REM 20-25%

Question 18

how is sleep regulated

Answer 18

diffuse modulatory neurotransmision system
NE/5-HT neurons in brain stem
thalamus control rhythmic behaviour
inhibit motor neuron to prevent muscle contraction

Question 19

what does lesioning brain stem cause

Answer 19

sleep/coma
activation of brain stem neuron has downstream impacts for neuron, precede awakening, stimulating brain stem cause awakening

Question 20

give an overview of non-REM stage sleep brain characteristic

Answer 20

slow-wave
less firing in brain stem
reduce muscle tension, low movement, temp, energy consumpts

Question 21

give summary of REM stage sleep characteristics

Answer 21

similar to awake firing states, no frontal lobe activities
inhibit motor neuron
low voltage fast EEG, muscle paralysis, movement commanded by brain not carry out
dreamings

Question 22

give theories of dreaming

Answer 22

strange imagery- brain isn’t fully functional
circuit testing
exercise synapses when no external activity to ensure work
memory consolidation = learning

Question 23

define circadian rhythm

Answer 23

endogenous and persist without environmental cues, modulated by external cues (zeitgeber) adopting rhythm to environment. can usually require sensory stimulation but works without as well

Question 24

what is main circadian clock

Answer 24

suprachiasmatic nucleus, lesioning causes decreased CR, regulates sleep timings

Question 25

what provides input to SCN for timing sleeps

Answer 25

intrinsically photosensitive ganglion cells in eyes

Question 26

what is a K complex (stage 2)

Answer 26

delta wave, maintain sleep and memory consolidation

Question 27

what are sleep spindles (stage 2)

Answer 27

brief powerful burst of neuron fires at superior temporal gyri, cc, thalamus
role in memory consolidation

Question 28

what is deepest sleep wave type?

Answer 28

delta

Question 29

what is awake wave type?

Answer 29

beta