WEEK 3: Sleep Physiology and Disorders [Salonga] Flashcards
is a state in which the person is aware of and
responds to sensory input from the environment
wakefulness
a state of behavioral quiescence accompanied by
an elevated arousal threshold and a species-specific sleep
posture (recumbent sleep posture, closed eyes, diminished
responsiveness to external stimuli and decrease in or
absence of movements)
Sleep
Sleep is an active process, irreversible state of responsiveness to the stimuli of the outside world. T or F
F. sleep reversible state of unresponsiveness
give 5 functions of sleep?
- Memory consolidation
- Energy conservation
- Body growth
- Regulation of immune function
- Protective behavioral adaptation
2 classifications in the nomenclature in the stages of sleep?
R&K and AASM
stages of sleep in R&K
wake (Stage W)
NREM (Stages 1 to 4)
REM (stage REM)
stages of sleep in AASM?
Wake: Stage W
NREM: Stage N1, N2, N3 (N3+N4)
REM: Stage R
NREM and REM occur in alternating cycles, each lasting approx __________ witha total of _________ cycles
90 - 100 mins; 4-5 cycles
in healthy adults, NREM sleep accounts for how many percent of sleep time?
75-90%
REM sleep accounts for how many % of sleep time?
10 - 25 %
in NREM, how many percent is accounted for each sleep time per stage?
Stage 1: 3 -5%
Stage 2: 50 - 60%
Stage 3 and 4: 10 - 20%
newborn sleeps approximately how many hours?
16-20 hrs
how many hrs of sleep in childhood?
10 hrs
In the full-term newborn, sleep cycles last approximately___________ alternating through a ______ hour
inter-feeding period).
60
minutes (50% NREM, 50% REM;
3-4 h
2 basic process in the regulation of sleep and wakefulness?
Process C (Circadian Process) Process S (Sleep homeostasis)
There are two circadian peaks in wakefulness: one is during _________, and another is during ___________
Sleep propensity is least during these peaks of
circadian rhythms of arousal
one
occurring (early evening) and a second peak (late
morning).
greatest sleep propensity is during periods of?
between 3 to 5 am and early-mid afternoon between 3 to 5 pm
is characterized by an increase in sleep pressure
following sleep deprivation that is related to the duration
of prior wakefulness followed by a decline in sleep need
as sleep accumulates.
Sleep Homeostasis
refers to the short-lived reduction
of alertness that occurs immediately following awakening
from sleep and disappears within 2 to 4 hours.
Sleep Inertia (process W)
2 mechanisms in the control of daily rhythm of sleep and arousal?
Suprachiasmatic nucleus of the hypothalamus (body clock)
Pineal Gland’s secretion of melatonin
this sets the suprachiasmatic clock?
Light
tiny endocrine gland situated at the
center of the brain
Pineal Gland
major pineal hormone?
Melatonin
melatonin is derived from?
Tryptophan
light supresses/increases melatonin secretion?
supresses
2 major RF ascending pathways projections into the brain?
Dorsal pathway and ventral pathway
Trace the dorsal pathway?
Dorsal pathway
→ thalamus
→ cerebral cortex
(thalamocortical system)
Trace the ventral pathway?
Ventral pathway → subthalamus and posterior
hypothalamus → basal forebrain and septum → cerebral
cortex
Descending RAS function?
connects to the cerebellum and to
nerves responsible for the various senses; helps maintain our posture and
balance in wake state
Most wake circuits originate in the \_\_\_\_\_\_\_\_ which stimulate the thalamus, hypothalamus (Hyp) and basal forebrain. These projections also inhibit sleep centers
Brain stem arousal
nuclei (BAN),
Centers for NREM sleep?
Forebrain (anterior hypothalamus-preoptic region,
including ventrolateral preoptic area [VLPO] and basal
forebrain)
neurotransmitters of NREM sleep?
serotonin and GABA; others are adenosine and norepinephrine.
control centers for REM sleep?
Pons (pedunculopontine tegmental nuclei and the
laterodorsal tegmental nuclei)
Brainstem reticular formation, especially oral pontine reticular formation,
other brainstem (lower medullary) and spinal cord
neurons
Neurotransmitters for REM sleep?
Ach!!! others include GABA and glycine
circadian pacemaker?
Suprachiasmatic nucleus
Hypothalamus control of sleep, pls trace?
SCN > Supraventricular zone, Dorsomedial nucleus > Paraventricular nucleus, lateral Hypothalamus, VLPO (ventrolateral preoptic nucleus)
The PVN is stimulated by the SCN, in a circadian fashion, to produce \_\_\_\_\_\_\_\_\_\_
corticotrophin releasing
factor
(CRF) which acts on pituitary gland, which in turn produces ACTH > adrenal glands will then release cortisol
______is one of the factors involved in the sleep/wake cycle
through a feedback system whereby it can then influence
activity in the hypothalamus.
Cortisol
is considered an underlying cause of insomnia and may be related to dysfunction of the HPA axis.
Hyperarousal
there is thought to be reduced basal
ACTH secretion and a reduction of central CRF. hyper/hypoarousal?
Hypoarousal
hypoarousal will lead to? hyperarousal will lead to?
sleep
hallucinations
Body temperature is ______in the early morning,
rising throughout the morning and then staying fairly steady
until it begins to ________ in the late evening.
also at its lowest ;
decline again
The human sleep–wake cycle is closely age linked: pls enumerate
newborn baby sleeps from 16 to 20 h a day
o child: 10 to 12 h.
o total sleep time drops to 9 to 10 h by mid-adolescence
and to about 7 to 7.5 h during young adulthood
o gradual decline to about 6.5 h develops in late adult life
Relaxed wakefulness (W) with the eyes closed is accompanied in the electroencephalogram (EEG) by\_\_\_\_\_\_\_\_\_\_\_\_
posterior alpha waves of 9 to 11 Hz (cycles per second) and
intermixed low-voltage fast activity of mixed frequency
With drowsiness, as the first stage of sleep sets in, the
eyelids begin to droop, the eyes may rove slowly from
side to side, and the pupils become smaller, the muscles
relax and the EEG pattern changes to one of
progressively lower voltage and mixed frequency with a
loss of alpha waves; this is associated with slow, rolling
eye movements: what stage of sleep?
N1 stage
there is the appearance of 0.5- to 2-s bursts of biparietal
12- to 14-Hz waves (sleep spindles) and intermittent highamplitude,
central-parietal sharp slow-wave complexes
(vertex waves) on EEG. what stage of sleep?
N2
represents slow-wave sleep with predominant theta
rhythms
o The first three stages are the NREM sleep.
N3 stage 3 of sleep
deep slow wave sleep with a preponderance of delta
frequency activity. Vertex waves and sleep spindles are
no longer evident.
REM sleep
is associated with further reduction in muscle
tone except in the extraocular muscles and with bursts of
rapid eye movement thus the term rapid eye movement
REM sleep
In the first portion of a typical night’s sleep, the normal young
and middle-aged adult passes successively through stages
N1, N2, N3, and R (REM) sleep. t or F?
T
T or F? The first REM period may be brief; the
later cycles have less stage N3 sleep or none at all.
T
In the latter portion of a night’s sleep, the cycles consist
essentially of two alternating stages—REM sleep and stage
N2 (spindle– K-complex) sleep. T or F?
T
What stage of sleep is this EEG characteristic: posterior reactive alpha rhythm
W - awake
What stage of sleep is this EEG characteristic: diffuse theta and loss of alpha
Drowsy - stage 1
What stage of sleep is this EEG characteristic: diffuse theta
REM - predominance of dreaming
What stage of sleep is this EEG characteristic: Sleep spindles and K complexes?
Stage 2 - light sleep
What stage of sleep is this EEG characteristic: hihg voltage theta and delta activity
stage 3 and 4 (N3) - deep sleep
Much of the night’s complex visual dreaming has been found to occur in the__________, with the qualifications noted below, and dreams are recalled most consistently if the subject is awakened during this time.
REM period
Subjects are easily aroused from REM sleep, but arousing a person during stage N3 is more difficult T or F?
T
uncontrollable random sleep attacks
Narcolepsy
temporary cessation of breathing while sleeping usually involving loud snoring
Sleep apnea
Circadian Rhythm sleep disorder: symptoms include varying degrees of difficulty in initiating or maintain sleep, daytime fatigue, decrements in daytime alertness and performance. resolves without treatment after 2 to 7 days
jet lag type
Circadian Rhythm sleep disorder: late appearance of sleep (around 2 am) but normal total sleep time and architecture which lead to sleep onset insomnia and difficulty awakening at desired time
Delayed sleep phase type
Circadian Rhythm sleep disorder: Symptoms of insomnia or excessive sleepiness, adaptation takes 1 to 2 weeks
shift work type
Disorder that produces complaints of insomnia or excessive sleepiness
▪ Intrinsic sleep disorders
▪ Extrinsic sleep disorders
▪ Circadian Rhythm Sleep Disorders
Dyssomnias
Disorders that intrude into or occur during sleep but do not result in insomnia or excessive sleepiness: Arousal Disorders ▪ Sleep-wake transition disorders ▪ REM related Parasomnias ▪ Other Parasomnias
Parasomnias
Happens during partial arousal from stage 4 sleep
o Usually begins with piercing scream
It usually occurs soon after falling asleep, during stage 3 or 4 sleep
Sleep terror
o occurs during any sleep stage
o Is more frequent among children
Somniloquy
These are disorders occurring during deep sleep
o 1. Sleep walking (somnambulism) o 2. Sleep terrors or night terrors (pavor nocturnus) o 3. Sleep-related enuresis o 4. Bruxism o 5. Sleep-taking (somniloquy)
sleep disorder associated with HLA DR2
narcolepsy
aka ekbom sndrome?
restless leg syndrme
episodic hypersomnolence aka?
Kleine levin syndrome
REM sleep disorders?
Narcolepsy
Nightmare
REM behavior disorder
chronic paroxysmal hemicrania
Initial step in sleep disorders treatments
lifestyle changes that include a healthy diet, regular exercise and good habits
pharmacological mx:
Dieatary supplements: melatonin and L tryptophan
short acting benzodiazepines
z drugs: zolpedium
low dse antridepressants
