Chapter 14 Sleep Flashcards
When talking about sleep there are three things to keep in mind:
- Sleep is different for individuals
- We adapt easily to changes in sleep
- Sleep Deprivation is almost always in conjunction with stress
What are Recuperation Theories?
-Sleep is needed to restore homeostasis
wakefulness causes deviation from homeostasis
What are the Adaptation Theories?
- Sleep is the result of an internal timing mechanism
- Sleep evolved to protect us from the dangers of the night
Prey sleep less than predators
How is Sleep studied?
Using EEG (Electroencephalogram)
There are five stages of sleep:
- Wakefulness
- Stage 1 Sleep
- Stage 2 Sleep
- Slow-Wave (deep) Sleep
- REM
Wakefulness has two basic patterns of wave activity:
- Alpha: regular, medium frequency (8-12 hz)
- occurs when eyes are closed and relaxed - Beta: irregular and lower amplitude (13-30 hz)
- shows asynchrony due to multiple neural circuits at work
What waves characterize stage 1 sleep?
Theta Waves (3.5-7.5 Hz)
- transition between sleep and wakefulness
- rolling eye movements
- lasts about 10 minutes
Stage 2 Sleep has what two characteristics?
- Sleep Spindles
2. K Complexes
What are sleep spindles?
mechanism that decreases the brains sensitivity to sensory input - wants you to stay asleep
Found in stages 1-4
What are K Complexes?
Only found during stage 2 - triggered by noises
What waves are seen in stages 3 and 4?
High amplitude delta waves (>3.5 Hz)
What is the deepest stage of sleep?
Stage 4 Slow Wave Sleep - if woken, will be groggy and confused
What type of wave activity is seen during REM?
Theta and Beta = brain is active
If woken during REM what is a person like?
Alert and attentive
What is Complete Muscle Atonia and why is it important during REM?
ACh is blocked= paralysis
Prevents us from acting out our dreams
What does a typical nights sleep look like?
90 minute cycle:
- 4-5 periods of REM sleep (each about 30 minutes long)
-
What are the effects of sleep deprivation as predicted by the Recuperation Theories?
- Long periods of wakefulness will result in disturbances
- disturbances will get worse as deprivation continues
- after deprivation, much of the missed sleep will be regained
What are two classic sleep deprivation case studies?
- Sleep Deprived Students
2. Randy Gardner
What is the effect of 3-4 hours of deprivation in one night?
- increased sleepines
- Disturbances displayed on written tests of mood
- Poor performance on tests of vigilance
- slow reaction time
What is the effect of 2-3 days of continuous deprivation
- Experience microsleeps, naps of 2-3 seconds
- difficulty updating plans and strategies
- difficulty thinking outside the box (innovative, lateral insightful thinking)
The Circadian Rhythm is a ______ hour cycle
25
What are zeitgebers?
Light-Dark environmental cues that entrain circadian rhythms
What are free-running rhythms?
circadian rhythms in constant environments: no temporal cues (remove zeitgebers)
What is internal desynchronization?
when sleep-wake and body temperature cycles break away from eachother
Where in the brain is the circadian clock?
Suprachiasmatic Nuclei (SCN)
What is Melnopsin?
Photochemical in ganglion cells that activate to gradual changes in light and transmit info from the retina to the rest of the brain
What two areas of the hypothalamus are involved in sleep?
posterior hypothalamus (wakefulness) and anterior hypothalamus (sleep)
What are four pieces of evidence that the Reticular Activating System is involved in sleep?
- cats with midcollicular transection displayed pattern of continuous slow-wave sleep
- Lesions at midcollicular level that damaged core of reticular formation produged a corical EEG indicative of continuous slow-wave sleep
- Electrical stimulation of the pontine reticular formation desynchronized the cortical EEG and awakened cats
- Cats with transection of the caudal brain stem displayed a normal sleep-wake cycle
What is REM sleep controlled by?
a variety of nuclei scattered throughout the caudal reticular formation
What four parts of the brain are involved in sleep?
Anterior Hypothalamus: sleep
Posterior Hypothalamus: wakefulness
Reticular Activating System: maintaining wakefulness
Caudal Reticular Formation Nuclei: REM
What are three classes of hypnotic drugs?
- Benzodiazepines
- Imidazopyridines
- 5-HTP
What are three classes of antihypnotic drugs?
- cocaine-derived stimulants
- amphetamine-derived stimulants
- tricyclic antidepressants
How do antihypnotic drugs promote wakefulness?
boost activity of catecholamines (epenephrine, norepinephrine, and dopamine) - by increasing their release into synapse, by blocking reuptake from synapses, or both
Where is melatonin produced?
The pineal gland
Define Chronobiotic
a substance that adjusts the timing of internal biological rhythms
*melatonin is chronobiotic
Many cases of insomnia are iatrogenic, what does this mean?
Physician-created = because of sleeping pills prescribed by doctors
Leads to Drug-dependency insomnia
What are six ways to get a good nights sleep?
- Avoid stressful activity before bedtime
- Sleep and wake-up at regular times
- Sleep in a cool room
- Avoid caffeine, taking naps or watching tv/internet before bed
- Sleep only when you’re tired
- Get out of bed if you can’t sleep and go back when you are tired
What is sleep apnea?
- briefly stop breathing during sleep
- CO2 in the blood stimulates chemoreceptors that causes the person to wake up gasping for air
What is narcalepsy?
Sleep attack - overwhelming urge to sleep mostly durin gmonotonous boring tasks
-REM phenomena
