Sleep Study

Question 1

What is actigraphy?

Answer 1

motion detector

reinforces/compliments sleep diary

Question 2

What is the utility of actigraphy?

Answer 2

objective quantification of sleep
objective assessment of sleep pattern
can be sueful for assessing larger numbers of people for sleep quantity

Question 3

What is the mutliple sleep latency test?

Answer 3

objective measure of sleepiness

20 minute opportunities to nap every 2 hours for 5 sessions ina row
unit of measure is minutes from lights out to sleep onset

normal is >10 miuntes
pathologically sleepy is <8 minutes
REM sleep during more than one of these naps is normal

Question 4

What is sleep?

Answer 4

defined as unconsciousness from which person can be aroused by asensory or other stimuli

contrast to coma and anesthesia which are unconsciousnessfrom which person can be aroused

Question 5

What is teh function of NREM?

Answer 5

growth, tissue repair, clearance of wastes
enhancement of immune system
restoration of cerebral energy stores

Question 6

What is the function of REM?

Answer 6

processing of information
unlearning irrelevant information
memory consolidation
facilitating learning and memory

Question 7

What is NREM sleep properties?

Answer 7

includes slow-wave sleep
sometimes referred to as dreamless sleep
dreams and nightmares may occur in NREM
dreams usually not recalled

Question 8

What are the properties of rem sleep?

Answer 8

associated with active dreaming
typically awaken in morning during an episode of REM sleep
sometimes referred to as paradoxical sleep as EEG is similar to wakefulness

Question 9

What is sleep-wake cycle: effected by circadian factors and duratioon of wakefulness and sleep controlled?

Answer 9

homeostatic process: longer awake the greater propensity to sleep

process C: Circadian oscillatory component affecting the propensity for sleep adn waking

Question 10

what is process H of sleep wake cycle?

Answer 10

homeostatic process; longer awake the greater propensity to sleep

Question 11

What is process C of sleep wake cycle?

Answer 11

circadian oscillatory component affecting the propensity for sleep and waking

Question 12

What are the circadian factors of sleep regulation?

Answer 12

internal biological clock

• -sleepy at night
• -awake during the day

approximate 24-hour period

composed of about 10,000 neurons in suprachiasmatic nucleus (SCN)
-hypothalamus

regulates endogenous biological rythms

• including sleep-wake cycle
• entrained or reset the day length by environmental photoperiod
• resetting is mediated through photoreceptors in the retina which send signals to the SCN

Question 13

What is the sleep-wake model?

Answer 13

as time in the awake state increases, there is increased drive to sleep

Question 14

What is wake-promoting factors?

Answer 14

Substance P
corticotrophin
thyrotopin - releasing factor
vasoactive  intestinal peptinde
neurotensin
epinephrine
histamine
glutamate
cortisol
serotonin

Question 15

What are sleep-promoting factors?

Answer 15

peptides
delta-sleep inducing peptide
alpha-melanocyte stimulating horomone
growth horomone-releasing factor
gamma-aminobutyric acid
cytokines, ILs
prostaglandin D2
adenosine
cholecystokinin, somatostatin
serotonin

Question 16

Wakefulness is promoted by what?

Answer 16

icnreased excitatory and decreased inhibitory neuromodulators and by then circadian homeostatic centers

Question 17

What causes NREM sleep?

Answer 17

brainstem excittatory and hhypothalamic circadian and homeostatic factors decrease

Question 18

Whaen does REM sleep occur?

Answer 18

when reduced NE and serotonin release inhibition of pontine PPT and LDT cholinergic neruons which activate the REM system

Question 19

What neurotransmitters promote REM sleep?

Answer 19

decreased acetylcholine and dfrom decreased NE and serotonin

Question 20

What neurotransmitters promote wakening?

Answer 20

hypothalamus leading to decreased GABA, increased histamine and increased activation of thalamus and cortex

as well as increased NE and serotonin leading to decreased acetylcholine

Question 21

What neurotransmitters lead to NREM sleep?

Answer 21

increased GABA
decreaased histamine
decreased activation of the thalamus and cortex

Question 22

What is NREM sleep signaled by in the neurons?

Answer 22

mean discharge rate of neurons decreased

cerebral glucose utilization decreased overall

Question 23

What is REM sleep singaled by in central nervous system activation?

Answer 23

mean discharge rate of neurons increased in many regions
-PGO spikes
-REMs
cerebral glucose utilization increased and resembles W
cerebral blood flow greatly increased

Question 24

What is the somatic acitvity of REM sleep?

Answer 24

• paralysis
• -postsynaptic inhibition of motoneurons
• -hyperpolarization of motoneuron membranes
• phasic
• -rapid eye movements
• -muscle twitches

Question 25

What is the breathing pattern of NREM sleep?

Answer 25

periodic breathing noted in stage 1 and 2 but regular breathing occurs in stage 3 and 4

Question 26

What is the breathing pattern in REM sleep?

Answer 26

electrooculogram -- phasic rapid eye movments characteristic REM sleep -- irregularities in timing and amplitude of ventilatory movements rae noted paradoxical respiration --rib cage moves inward when abdoment moves outward

Question 27

What are the ventilation changes of sleep?

Answer 27

``` significantly altered with state decrease in vent during sleep is greater than a concurrent decrease in metabolic rate PaCO2 increases sleep induced hypoventilation unique to humans among mammals ```

Question 28

What are the hemodynamic changes of sleep?

Answer 28

alteration in ANS parasympathetic activity predominates during both NREM and REM sleep HR and CO decrease cerebral blood flow decreases in NREM but increases in REM sleep during phasic REM, bp and hr are unstable due to phasic vagal inhibition and sympathetic activation overall there is a slight decrease in total vasc resistance during sleep

Question 29

What are the endocrine changes of sleep?

Answer 29

growth horomone -plasma conc peak 90 min after sleep onset -higher in men than women duration fo 1-3 hours related to SWS -sleep deprivation suppresses GH secretion

Question 30

What is parathyroid endocrine changes during sleep?

Answer 30

increased levels during sleep compared to awaken state | peaks between 2 and 4 am

Question 31

What is the endocrine changes of adrenocorticotropic horomone?

Answer 31

cortisol decreases with sleep onset | cortisol levels lowest in early part of sleep, highest from 4 am to 8 am

Question 32

What is the thermoregulation of NREM and REM sleep?

Answer 32

``` NREM -lowered temp set point --shivering threshold lower --sweating at normal ambient temp REM -no regulation --no shivering response --no sweating at high ambient temperature --body temperature drifts toward ambient temp ```