Sleep Stages and EEG Patterns

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Questions and Answers

What role does adenosine play during periods of wakefulness?

Stimulates neural activity and promotes wakefulness

Modulates respiratory function and reduces sleep apnea

Enhances cognitive function and emotional well-being

Inhibits neural activity and promotes sleep (correct)

Which statement best describes the underlying issue of obstructive sleep apnea?

It results from muscle spasms or lack of muscle tone obstructing airways. (correct)

It is characterized by excessive sleepiness due to prolonged sleep deprivation.

It is caused by neurological failure to drive respiratory functions.

It primarily occurs due to disturbances in sleep architecture.

What is a significant consequence of prolonged use of sleeping pills related to insomnia?

They prevent the accumulation of adenosine during wakefulness.

They provide immediate relief from sleep disorders with no side effects.

They enhance deep sleep and reduce overall sleep time.

They can lead to tolerance and withdrawal symptoms, including insomnia. (correct)

Which disorder is characterized by continuous involuntary limb movements during sleep?

Periodic limb movement disorder Signup and view all the answers

What happens to adenosine levels during slow-wave sleep (SWS)?

Adenosine is broken down, reducing its inhibitory effects on neural activity. Signup and view all the answers

What is the primary role of the medial prefrontal cortex in relation to dreaming?

Its activity is low during dreaming, reflecting disorganization. Signup and view all the answers

What effect do bilateral lesions in the temporo-parieto junction have on dreaming?

They lead to cessation of dreaming. Signup and view all the answers

Which theory suggests that sleep is necessary to restore physiological stability in the body?

Recuperation theory of sleep. Signup and view all the answers

During which stage of sleep does metabolism lower to allow for restorative mechanisms in the cells?

Slow-wave sleep. Signup and view all the answers

What is a common misconception about the function of sleep in most mammals and birds?

It functions solely as a protective measure from predation. Signup and view all the answers

What is observed in individuals who experience sleep deprivation?

A tendency to fall asleep quickly when given the opportunity. Signup and view all the answers

Which area is associated with both REM and NREM dreaming?

Temporo-parieto junction. Signup and view all the answers

What physiological state is characterized by high activity of noradrenergic neurons in the locus coeruleus (LC)?

Wakefulness Signup and view all the answers

Which area is primarily responsible for promoting sleep through the activity of its neurons?

Preoptic area Signup and view all the answers

What happens to serotonergic neurons in the raphe nuclei during REM sleep?

They become completely inactive Signup and view all the answers

How does electrical stimulation of the preoptic area affect an animal's state of consciousness?

Causes drowsiness and sleep Signup and view all the answers

Which neurotransmitter system is least active during slow-wave sleep?

Histaminergic Signup and view all the answers

What is the main effect of the destruction of the preoptic area in rats?

Total insomnia Signup and view all the answers

What allows for the establishment of distinct periods of sleep and wakefulness?

Reciprocal inhibition of neurons Signup and view all the answers

Which of the following describes the activity of neurons during REM sleep deprivation?

Spontaneous penile erections during slow-wave sleep Signup and view all the answers

Which major function is regulated by various nuclei within the caudal reticular formation?

Controlling indices of REM sleep Signup and view all the answers

What characterizes the reticular activating system during high levels of activity?

Promoting wakefulness Signup and view all the answers

What is the primary function of the suprachiasmatic nuclei (SCN)?

To synchronize behaviors with a 24-hour light/dark cycle Signup and view all the answers

How can exposure to bright light affect circadian rhythms?

It can either delay or advance the cycle depending on timing Signup and view all the answers

What mechanism enables people who are blind to maintain circadian rhythms?

Melanopsin-containing ganglion cells transmit light information Signup and view all the answers

Which of the following is a potential consequence of shift work and jet lag?

Sleep disturbances and fatigue Signup and view all the answers

What is the role of zeitgebers in synchronizing circadian rhythms?

They help adjust the internal clock to external environmental signals Signup and view all the answers

What happens to SCN neurons during the night?

They tend to be inactive Signup and view all the answers

Which process would likely NOT be affected by bilateral SCN lesions?

Feeding and drinking patterns Signup and view all the answers

Circadian genes determine what aspect of an animal's biological rhythm?

The duration of free-running circadian rhythms Signup and view all the answers

What is primarily required to resolve the symptoms of jet lag or shift work?

Synchronization of the internal clock to external cues Signup and view all the answers

Which of the following statements accurately reflects the relationship between circadian genes and evolutionary history?

Similar circadian genes across species indicate they evolved early in evolutionary history. Signup and view all the answers

What is the primary factor regulating the molecular circadian timing mechanisms in cells?

Neural and hormonal signals from the SCN. Signup and view all the answers

How do the sleep patterns of most mammals and human infants differ from those of human adults?

Infants and mammals display polyphasic sleep cycles. Signup and view all the answers

What characteristic is associated with advanced sleep phase syndrome?

Individuals awaken several hours earlier than average. Signup and view all the answers

Which hormone does the pineal gland secrete in response to input from the SCN during the night?

Melatonin Signup and view all the answers

What effect does melatonin administration have on jet lag and shift work?

It alleviates adverse effects when taken at the appropriate time. Signup and view all the answers

What is the neuromodulator released by the locus coeruleus during wakefulness?

Norepinephrine Signup and view all the answers

In which sleep state are acetylcholine levels high?

Wakefulness and REM sleep Signup and view all the answers

What is the characteristic change in activity of noradrenergic neurons during different sleep stages?

High during wakefulness, low during slow-wave sleep, and minimal during REM sleep. Signup and view all the answers

What defines the term 'zeitgeber' in relation to circadian rhythms?

External cues that synchronize biological cycles. Signup and view all the answers

Study Notes

Sleep Stages

Sleep is divided into stages based on three psychophysiological measures: EEG (electroencephalogram), EOG (electrooculogram), and EMG (electromyogram).
EEG patterns show different brain wave activity:
- Synchronous activity - neurons firing in synchrony produce large, clear waves.
- Desynchronous activity - neurons firing randomly produce small, chaotic waves.
- Alpha waves (8-12 Hz) - present during quiet rest, eyes closed.
- Beta waves (13-30 Hz) - present during alertness and active thought.
Stage 1 sleep starts with alpha waves transitioning to low-voltage, high-frequency waves. Initial stage 1 is marked by theta waves, followed by emergent stage 1 which has theta and beta waves, REMs, muscle paralysis. Hypnic jerks may occur.
Stage 2 sleep has slightly higher amplitude and lower frequency waves than stage 1. Characterized by K complexes (sudden, sharp waveforms) and sleep spindles (0.5-2s bursts of 11-15Hz waves).
Stage 3 sleep, also called slow-wave sleep (SWS), is defined by delta waves (1-2 Hz). It is the deepest stage of sleep, with loud noises needed to awaken the person.
After stage 3, the sleeper cycles back through the stages.

REM Sleep

Emergent stage 1 (REM sleep) is characterized by brain activity similar to wakefulness, rapid eye movements (REMs), and paralysis of large muscle groups. Dreaming often occurs in REM sleep.

Effects and Theories of Sleep Deprivation

Sleep deprivation negatively affects: mood, sustained attention, and executive functions (problem solving, etc.). However, some cognitive functions may be unaffected.
Longer sleep studies show no clear deficit in shorter sleep periods.
Microsleeps - brief periods of sleep can occur after 2-3 days of deprivation.
REM rebound occurs after deprivation, with increased REM sleep in the following days.

Theories on Why We Sleep

Recuperation theories: Sleep restores the body's internal balance and recovers from the effects of wakeful activities, with waste products being reduced during SWS. High metabolic rates during wakefulness produce waste products, sleep eliminates them.
Adaptation theories: Sleep is a reaction to an internal 24-hour timing, offering protection (less susceptible to incident) and carrying out brain functions impossible during wakefulness.

How Our Internal Clock Works

The internal 24-hour timing is a circadian rhythm controlled by the body, with environmental cues (zeitgebers) synchronizing it.
Free-running rhythms are circadian rhythms in constant environments with an average period of 24.2 hours in humans.
Environmental cues like light influence this rhythm, with exposure to light changing how sleep-wake cycles adjust. Jet lag and shift work disrupt our internal clocks.

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Description

This quiz focuses on the various stages of sleep and their corresponding EEG patterns. It covers the differences in brain wave activity during different sleep stages and includes phenomena such as hypnic jerks and sleep spindles. Test your understanding of sleep physiology and its psychophysiological measures.