Biological Rhythms & Sleep

These flashcards cover key concepts related to biological rhythms and sleep, including why sleep is necessary, various sleep stages, effects of sleep deprivation, and related disorders.

Why do we sleep?

We spend 1/3 of our lives asleep, which serves functions like energy saving, restoration, homeostasis, and memory consolidation.

What are the effects of sleep deprivation?

can lead to brain cell damage, irritability,

cognitive impairment,

memory lapses,

and other health risks.

What is memory consolidation?

the process by which recent experiences are transformed into stable, long-term memories,

often occurring during sleep.

What happens during Non-REM sleep?

, the brain replays neural firing patterns,

solidifying memories and facilitating synapse growth.

What is REM sleep associated with?

associated with vivid dreaming and is thought to play a role in emotional memory consolidation.

prunes redundant synapses, preserving newly formed synapses

What are sleep spindles?

oscillatory bursts of brain activity during sleep,

mostly occurring in stage 2 sleep, that

help with memory consolidation.

What does EEG stand for?

electroencephalography,

a technique used to measure electrical activity in the brain.

What distinguishes REM from non-REM sleep?

characterised by rapid eye movement and

a brain activity pattern similar to awake states, but with muscle atonia.

What are circadian rhythms?

biological processes that follow a roughly 24-hour cycle,

influencing sleep/wake cycles, hormones, and mood.

What are Zeitgebers?

external cues, like light and social signals, that help synchronize our circadian rhythms to the 24-hour day.

What is the role of the Suprachiasmatic Nucleus?

is the master clock of the body

that regulates circadian rhythms by stimulating melatonin release.

What is melatonin?

hormone released by the pineal gland

that helps regulate sleep-wake cycles and is influenced by light exposure.

How does the reticular formation affect arousal?

responsible for arousal

; damage to it can lead to low arousal levels or coma.

What is insomnia?

is a sleep disorder characterised by difficulty falling or staying asleep,

leading to impaired daytime functioning.

What triggers narcolepsy?

may be triggered by excitement and is associated with

sudden sleep attacks and muscle weakness (cataplexy).

What is the biological clock?

The system in the body that regulates sleep,

wakefulness, and other circadian rhythms.

What is the difference between a coma state and a vegetative state?

In a vegetative state, there can be alternating periods of sleep and arousal, while coma is an extended period of unconsciousness without wakefulness.

What is sleepwalking?

a phenomenon where a person is partially awake

and can perform activities while still being asleep.

What are the characteristics of stage 1 sleep?

has mostly alpha and beta activity

with irregular, low voltage waves as

the brain transitions from awake to asleep.

Describe the quality of sleep in the early night.

Echaracterized by deep slow-wave sleep (SWS),

predominantly stages 3 and 4.

What impact does sleep deprivation have on the immune system?

can impair the immune system, increasing the risk of illnesses.

What is hallucination in the context of sleep deprivation?

due to sleep deprivation are experiences of seeing,

hearing, or feeling things that are not present.

What does the term 'vegative state' mean?

a person shows wakefulness without awareness.

What are the key functions of sleep?

energy conservation,

restoration of the body,

maintenance of homeostasis, and memory consolidation.

At what stage does sleep paralysis commonly occur?

typically occurs during the transition between sleep and wakefulness

and is often associated with REM sleep.

What are some examples of natural zeitgebers?

include sunlight, temperature changes, and social interactions.

How does the body respond to prolonged sleep deprivation?

can lead to increased reaction times,

cognitive deficits, and health issues like

obesity and diabetes.

What is cataplexy?

sudden loss of muscle tone often triggered by strong emotions, commonly associated with narcolepsy.

How does the brain process memories during sleep?

, the brain 'practices' recent experiences,

thereby enhancing memory consolidation and recall.

What types of waves are predominantly associated with REM sleep?

resembles that of stage 1 sleep but is characterized by rapid eye movements.

What happens to synapses during REM sleep?

redundant synapses are pruned,

which helps in preserving newly formed synapses.

How does caffeine affect adenosine?

blocks neuroadenosine, a neuromodulator that promotes sleepiness and fatigue.

What is GABA's role in sleep?

that promotes sleep

by inhibiting neuronal activity,

reducing excitability.

gaba=baby=babies sleep

How does the SCN influence melatonin production?

the pineal gland to release melatonin when it gets dark,

signaling the body that it's time to sleep.

What physiological systems are affected by sleep?

affects multiple systems,

including cardiovascular, immune, and metabolic functions.

How do sleep spindles relate to learning?

increase in number after new learning

, indicating their role in consolidating memories.

What is the paradox of lucid dreaming?

the dreamer is aware they are dreaming and can often exert some control over the dream.

What is hypersomnia?

characterized by excessive daytime sleepiness and prolonged nighttime sleep.

What is a common treatment for insomnia?

include cognitive behavioral therapy,

lifestyle changes, and medication.

What role does the hypothalamus play in sleep?

regulates arousal, wakefulness, and sleep through various neurotransmitters.

What is the relationship between sleep and growth?

vital for growth;

adequate sleep is necessary for growth hormone release.

How can jet lag affect sleep patterns?

occurs when a person's circadian rhythms are out of sync

with the local time, leading to sleep disturbances.

What are some behavioral strategies to improve sleep?

include maintaining a regular sleep schedule,

creating a sleep-friendly environment,

and avoiding stimulants.

What significant event in sleep science is associated with Ralph & Menaker (1988)?

the SCN is autonomous and

can regulate circadian rhythms even when isolated.

Ventrolateral preoptic

nucleus (VLPO)

• in basal forebrain

• Lesions can cause insomnia

• activated as adenosine builds up in the cell afterburning energy Ventrolateral preoptic

  nucleus (VLPO)

RELAXATION

• eyes closed mainly alpha waves

STAGE ONE

Mostly alpha & beta activity.

The EEG is dominated by irregular,

jagged, and low voltage waves.

Brain activity begins to decline.

STAGE 2

sleep spindles and K-complexes

(transition from awake to asleep).

STAGES 3+ 4

• slow wave sleep

• increasing amounts of slow large amplitude

• highly synchronised neuronal activity

• slow heart rate