Term
| What can happen if a person doesn't sleep? |
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Definition
1. impaired memory
2. reduced cognitive abilities
3. mood swings
4. hallucinations
5. death |
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Term
| What does the circadian cycle depend on? |
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Definition
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Term
| What does the suprachiasmatic nucleus control (SCN)? |
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Definition
| circadian rhythm of sleep-wake cycle, body temperature, hormone secretion, urine production, and changes in blood pressure |
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Term
| What does the pineal gland synthesize? |
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Definition
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Term
| What does melatonin modulate? |
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Definition
| Brainstem circuits that govern sleep-wake cycle |
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Term
| What does the SCN generate? |
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Definition
| Alert signals that keep you awak |
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Term
| How does melatonin overcome alert signals from the SCN to induce sleep? |
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Definition
| As sleep load increases, it reduces the amplitude of alert signals from the SCN so that sleep can take over |
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Term
| What nucleoside is thought to be a component of the sleep load? |
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Definition
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Term
| What are the five stages of sleep as define by EEG? |
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Definition
1. Stage I
2. Stage II
3. Stage III
4. Stage IV
5. REM (rapid eye movement) |
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Term
| What are two other terms for sleep stages I through IV? |
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Definition
NREM - non-rapid eye movement
SWS - slow wave sleep |
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Term
| What kind of waves are characteristic of wakefulness? |
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Definition
| high frequency and low amplitude EEG waves - beta waves |
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Term
What type of brain waves characterize Stage I sleep?
What does this state feel like? |
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Definition
*slightly lower frequency and higher amplitude of EEG waves - theta waves
*drowsiness |
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Term
| What kind of brain waves characterize Stag II sleep? |
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Definition
1. still lower frequency and higher amplitude
2. presence of sleep spindles
3. see pattern called K-complex about every 2 minutes
a. periodic bursts of activity
b. last 1-2 seconds |
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Term
| What kind of brain waves characterize Stage III sleep? |
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Definition
1. moderate to deep sleep
2. frequency lower and amplitude higher 3. number of spindles decreases |
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Term
| What kind of brain waves characterize Stage IV sleep? |
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Definition
1. deepest level of sleep
2. characterized by low frequency, high amplitude EEG waves - delta waves
3. more difficult to awaken people from slow-wave sleep |
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Term
| About how long does it take to go from Phase I to Phase IV sleep? |
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Definition
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Term
| What physiological changes occur in NREM sleep? |
|
Definition
1. decrease in
a. muscle tone
b. heart rate
c. breathing
d. blood pressure
e. metabolic rate
f. body temperature
2. body movements reduced, but tossing and turning can occur
3. sleepwalking and sleep talking occur |
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Term
| What characterizes REM sleep? |
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Definition
1. EEG recordings show activity similar to awake state
2. increase in
a. blood pressure
b. heart rate
c. metabolism
3. characterized by dreaming, visual hallucinations, increased emotion, lack of self- reflection, and lack of volitional control
4. paralysis of large muscles (though not diaphragm and other muscles required for breathing)
5. penile erection |
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Term
| What effects are caused by a lack of REM sleep? |
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Definition
No obvious effects
REM rebound |
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Term
What percentage of sleep is REM sleep?
What proportion of dreaming is found in this stage, and what are dreams in this stage like? |
|
Definition
* 50% as baby, 25% as adult
* most dreams (but not all) occur in this stage, and they are more vivid and emotional |
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Term
What happens after the first cycle of REM is complete?
What is different after the second REM cycle? |
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Definition
Brain cycles backward through stages, then back to REM sleep
Stage IV does not usually occur after the second cycle |
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Term
How many cycles of REM sleep occur usually during an eight-hour sleep period?
How often do the rounds occur? |
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Definition
| After the second round, there are an 4-6 additional periods of REM sleep, each occurring about every 90 minutes |
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Term
| Which stage of sleep is it hardest to wake someone from? |
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Definition
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Term
| How do cycles of REM sleep change as the sleep cycles progress? |
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Definition
| Later cycles of REM sleep are longer. |
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Term
| What is the reticular activating system? |
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Definition
1. cholinergic neurons near junction of pons and midbrain
2. project to thalamocortical neurons 3. active during waking and REM sleep; quiet during NREM sleep
4. when stimulated causes awakening of sleeping animal |
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Term
| Where do neurons in the thalamus project from/to? |
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Definition
*receive projections from locus coeruleus, raphe nuclei, reticular activating system, and
tuberomammillary nucleus (TMN)
*thalamocortical neurons project from thalamus to cortex |
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Term
| Which drug keeps you awake by blocking adenosine? |
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Definition
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Term
| Which drugs put you to sleep by activating GABA transmitters (optic area)? |
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Definition
| benzodiazepines -> sleep drugs |
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Term
| Why does warm milk make you sleepy? |
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Definition
| Tryptophan, which is converted to melatonin |
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Term
| Which do histamine blockers make you drowsy? |
|
Definition
| blocking histamine receptors in your tuberomammillary nucleus, which normally helps keep you awake |
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Term
|
Definition
a. efferent signal to diaphragm insufficient to trigger inspiration
b. occurs in all sleep stages but more common in early stages of NREM sleep
c. occurs in only 5% of patients with apnea
d. most severe form Ondine’s curse, where breathing completely ceases during sleep |
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Term
Who is more likely to have RBD?
What causes it?
What is it associated with increased incidence of? |
|
Definition
*mainly affects men over 50
*brainstem disorder that prevents muscle paralysis
*Parkinson's |
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Term
| Patients suffering from which diseases are more likely to have sleep disturbances? |
|
Definition
| Alzheimer’s, Parkinson’s, and Huntington’s disease patients |
|
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Term
| What does lack of sleep cause increased incidence of? |
|
Definition
| obesity, cardiovascular disease, and diabetes |
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Term
| What characterizes the quality of sleep in an older person? |
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Definition
1. older individuals tend to sleep more lightly and for shorter times, though needing same amount of sleep as when younger
2. they have little or no slow-wave sleep 3. they wake up more frequently 4. pineal gland produces less melatonin 5. many sleep problems due to poor health, prescription drugs, urinary problems |
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Term
| What sleep conditions increase with incidence with age? |
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Definition
| insomnia, sleep apnea, and restless legs syndrome |
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Term
| Which sleep state most closely resembles being awake? |
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Definition
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Term
| Which brain circuit is usually active when awake but is also active during sleep |
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Definition
| The reticular activating center |
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Term
| What happens if you stimulate a sleeping animal's reticular activating center? |
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Definition
|
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Term
| What happens if you stimulate the thalamus of an animal? |
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Definition
| If it is awake, it will sleep |
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Term
| What regions of the brain are responsible for the awake state? |
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Definition
a. neurons in reticular activating system, locus coeruleus, and Raphe nuclei active
b. orexin-synthesizing neurons active, which reinforces wakefulness |
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Term
| What brain regions are responsible for the sleep state? |
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Definition
a. VLPO neurons active, which inhibit neurons responsible for wakefulness
b. orexin-synthesizing neurons inhibited |
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Term
| What is central vs. obstructive sleep apnea? |
|
Definition
central: efferent signal to diaphragm insufficient to signal inspiration
obstructive: partial or complete blockage of upper airway |
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Term
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Definition
| immature breathing control system may fail to arouse infant during episodes of apnea |
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Term
What is cataplexy?
What other condition is connected to it? |
|
Definition
Loss of muscle control during intense emotion
Narcolepsy |
|
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Term
| Loss of what type of neurons causes narcolepsy? |
|
Definition
| orexin/hypocretin-synthesizing neurons |
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