Case 6 sleep
1. What are the different sleep stages?
- First 4 stages are non REM. The
progression through these stages lakes
approximately 60-90 ruin and then the
cycle reverses and continues via stage 3 and
stage 2 sleep and then enters REM sleep
that lasts for 10-15 min. RUM sleep
appears to be associated with dreaming.
Following REM sleep the person would
typically re-enter stage 2 sleep and then
cycle through I lie other sleep stages again.
Each complete cycle takes approximately
90- 100 min. Early on, sleep is dominated
by stage 3 and stage A sleep, but towards
the end of sleep stage 4 steep shortens and
REM steep extends
- After the eyes are shut and a person
prepares to go to sleep, alpha waves—
waxing and waning bursts of 8- to 12-Hz
EEG waves—begin to punctuate the low-
voltage, high-frequency waves of alert
wakefulness. Then, as the person falls asleep, there is a sudden transition to a period of
stage 1 sleep EEG. The stage 1 sleep EEG is a low-voltage, high frequency signal that
is similar to, but slower than, that of alert wakefulness. the stage 2 sleep EEG has a
slightly higher amplitude and a lower frequency than the stage 1 EEG. The stage 3
sleep EEG is defined by a predominance of delta waves—the largest and slowest EEG
waves, with a frequency of 1 to 2 Hz. Once sleepers reach stage 3 EEG sleep, they
stay there for a time, and then they retreat back through the stages of sleep to stage 1.
each cycle tends to be about 90 minutes long and that, as the night progresses, more
and more time is spent in emergent stage 1 sleep, and less and less time is spent in the
other stages, particularly stage 3.
- REM sleep: correlation REM sleep and dreaming. What is distinctive about the
dreams during REM sleep is that they are
characterized by visual imagery, whereas
dreams during NREM sleep are of a more
“thinking” type. REM dreams are apt to include
a story that involves odd perceptions and the
sense that the reamer “is there” experiencing
sights, sounds, smells, and acts.
- NREM sleep: non rapid eye movement. NREM
3 is often referred to as slow-wave sleep (SWS),
after the delta waves that characterize it.
- Sleep deprivation: increases in irritability, difficulty in concentrating, and episodes of
disorientation. reported not feeling sleepy, yet their performance was still impaired.
Airline employees who work on schedules that give them little time to adapt to new
time zones show deficits in cognitive tasks and reduced volume of the brain’s
temporal lobe compared with employees on a schedule that permits more time to
recover from jet lag
1
, - Sleep recovery: In the first night of sleep recovery, stage 3 sleep shows the greatest
relative
- difference from normal. This increase in stage 3 sleep is usually at the expense of
stage 2 sleep. However, the rise in stage 3 sleep during recovery never completely
makes up for the deficit accumulated over the deprivation period. REM sleep in
recovery nights is more “intense” than normal, with a greater number of rapid eye
movements per period of time. So you never recover all lost sleep time, but you may
make up for the loss by having more intense sleep for a while.
- Sleep converges energy
- Sleep enforces niche adaptations: Almost all animals are either nocturnal or diurnal.
Thanks to these adaptations, each species is better at gathering food either at night or
in the daytime, and each species is also better at avoiding predators either during the
day or at night
- Sleep restores body and brain: Sleep also restores the brain by allowing it to get rid of
waste products. Glia control the flow of cerebrospinal fluid through a microscopic
network of channels throughout the brain, collecting and disposing of toxins that build
up
- Sleep aids memory consolidation: NREM aids consolidation of memory, specifically
declarative memory.
- Forebrain generates slow wave sleep: the forebrain alone can generate SWS, with no
contributions from the lower brain regions.
-
- reticular formation wakes up the forebrain
- pons triggers REM sleep: research pinpointed a specific region of the pons, just
ventral to the locus coeruleus, which is therefore called the subcoeruleus, where some
neurons are active only during REM sleep
2. What rests at what stage? How are different stages relevant to the brain and the
body?
- recuperation theories of sleep is that being awake disrupts the homeostasis (internal
physiological stability) of the body in some way and sleep is required to restore it.
sleepiness is triggered by a deviation from homeostasis caused by wakefulness and
that sleep is terminated by a return to homeostasis.
- adaptation theories of sleep is that sleep is not a reaction to the disruptive effects of
being awake but the result of an internal 24-hour timing mechanism—that is, we
2
1. What are the different sleep stages?
- First 4 stages are non REM. The
progression through these stages lakes
approximately 60-90 ruin and then the
cycle reverses and continues via stage 3 and
stage 2 sleep and then enters REM sleep
that lasts for 10-15 min. RUM sleep
appears to be associated with dreaming.
Following REM sleep the person would
typically re-enter stage 2 sleep and then
cycle through I lie other sleep stages again.
Each complete cycle takes approximately
90- 100 min. Early on, sleep is dominated
by stage 3 and stage A sleep, but towards
the end of sleep stage 4 steep shortens and
REM steep extends
- After the eyes are shut and a person
prepares to go to sleep, alpha waves—
waxing and waning bursts of 8- to 12-Hz
EEG waves—begin to punctuate the low-
voltage, high-frequency waves of alert
wakefulness. Then, as the person falls asleep, there is a sudden transition to a period of
stage 1 sleep EEG. The stage 1 sleep EEG is a low-voltage, high frequency signal that
is similar to, but slower than, that of alert wakefulness. the stage 2 sleep EEG has a
slightly higher amplitude and a lower frequency than the stage 1 EEG. The stage 3
sleep EEG is defined by a predominance of delta waves—the largest and slowest EEG
waves, with a frequency of 1 to 2 Hz. Once sleepers reach stage 3 EEG sleep, they
stay there for a time, and then they retreat back through the stages of sleep to stage 1.
each cycle tends to be about 90 minutes long and that, as the night progresses, more
and more time is spent in emergent stage 1 sleep, and less and less time is spent in the
other stages, particularly stage 3.
- REM sleep: correlation REM sleep and dreaming. What is distinctive about the
dreams during REM sleep is that they are
characterized by visual imagery, whereas
dreams during NREM sleep are of a more
“thinking” type. REM dreams are apt to include
a story that involves odd perceptions and the
sense that the reamer “is there” experiencing
sights, sounds, smells, and acts.
- NREM sleep: non rapid eye movement. NREM
3 is often referred to as slow-wave sleep (SWS),
after the delta waves that characterize it.
- Sleep deprivation: increases in irritability, difficulty in concentrating, and episodes of
disorientation. reported not feeling sleepy, yet their performance was still impaired.
Airline employees who work on schedules that give them little time to adapt to new
time zones show deficits in cognitive tasks and reduced volume of the brain’s
temporal lobe compared with employees on a schedule that permits more time to
recover from jet lag
1
, - Sleep recovery: In the first night of sleep recovery, stage 3 sleep shows the greatest
relative
- difference from normal. This increase in stage 3 sleep is usually at the expense of
stage 2 sleep. However, the rise in stage 3 sleep during recovery never completely
makes up for the deficit accumulated over the deprivation period. REM sleep in
recovery nights is more “intense” than normal, with a greater number of rapid eye
movements per period of time. So you never recover all lost sleep time, but you may
make up for the loss by having more intense sleep for a while.
- Sleep converges energy
- Sleep enforces niche adaptations: Almost all animals are either nocturnal or diurnal.
Thanks to these adaptations, each species is better at gathering food either at night or
in the daytime, and each species is also better at avoiding predators either during the
day or at night
- Sleep restores body and brain: Sleep also restores the brain by allowing it to get rid of
waste products. Glia control the flow of cerebrospinal fluid through a microscopic
network of channels throughout the brain, collecting and disposing of toxins that build
up
- Sleep aids memory consolidation: NREM aids consolidation of memory, specifically
declarative memory.
- Forebrain generates slow wave sleep: the forebrain alone can generate SWS, with no
contributions from the lower brain regions.
-
- reticular formation wakes up the forebrain
- pons triggers REM sleep: research pinpointed a specific region of the pons, just
ventral to the locus coeruleus, which is therefore called the subcoeruleus, where some
neurons are active only during REM sleep
2. What rests at what stage? How are different stages relevant to the brain and the
body?
- recuperation theories of sleep is that being awake disrupts the homeostasis (internal
physiological stability) of the body in some way and sleep is required to restore it.
sleepiness is triggered by a deviation from homeostasis caused by wakefulness and
that sleep is terminated by a return to homeostasis.
- adaptation theories of sleep is that sleep is not a reaction to the disruptive effects of
being awake but the result of an internal 24-hour timing mechanism—that is, we
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