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?

Sleep deprivation can lead to brain cell damage, irritability, cognitive impairment, memory lapses, and other health risks.

What is memory consolidation?

Memory consolidation is the process by which recent experiences are transformed into stable, long-term memories, often occurring during sleep.

What happens during Non-REM sleep?

During Non-REM sleep, the brain replays neural firing patterns, solidifying memories and facilitating synapse growth.

What is REM sleep associated with?

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

What are sleep spindles?

Sleep spindles are oscillatory bursts of brain activity during sleep, mostly occurring in stage 2 sleep, that help with memory consolidation.

What does EEG stand for?

EEG stands for electroencephalography, a technique used to measure electrical activity in the brain.

What distinguishes REM from non-REM sleep?

REM sleep is characterized by rapid eye movement and a brain activity pattern similar to awake states, but with muscle atonia.

What are circadian rhythms?

Circadian rhythms are biological processes that follow a roughly 24-hour cycle, influencing sleep/wake cycles, hormones, and mood.

What are Zeitgebers?

Zeitgebers are 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?

The Suprachiasmatic Nucleus (SCN) is the master clock of the body that regulates circadian rhythms by stimulating melatonin release.

What is melatonin?

Melatonin is a 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?

The reticular formation is responsible for arousal; damage to it can lead to low arousal levels or coma.

What is insomnia?

Insomnia is a sleep disorder characterized by difficulty falling or staying asleep, leading to impaired daytime functioning.

What triggers narcolepsy?

Narcolepsy may be triggered by excitement and is associated with sudden sleep attacks and muscle weakness (cataplexy).

What is the biological clock?

The biological clock is the system in the body that regulates sleep, wakefulness, and other circadian rhythms.

What is the difference between a comatose 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?

Sleepwalking is a phenomenon where a person is partially awake and can perform activities while still being asleep.

What are the characteristics of stage 1 sleep?

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.

Early-night sleep is characterized by deep slow-wave sleep (SWS), predominantly stages 3 and 4.

What impact does sleep deprivation have on the immune system?

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

What is hallucination in the context of sleep deprivation?

Hallucinations due to sleep deprivation are experiences of seeing, hearing, or feeling things that are not present.

What does the term 'vegative state' mean?

A vegetative state refers to a condition where a person shows wakefulness without awareness.

What are the key functions of sleep?

The key functions of sleep include energy conservation, restoration of the body, maintenance of homeostasis, and memory consolidation.

At what stage does sleep paralysis commonly occur?

Sleep paralysis typically occurs during the transition between sleep and wakefulness and is often associated with REM sleep.

What are some examples of natural zeitgebers?

Natural zeitgebers include sunlight, temperature changes, and social interactions.

How does the body respond to prolonged sleep deprivation?

Prolonged sleep deprivation can lead to increased reaction times, cognitive deficits, and health issues like obesity and diabetes.

What is cataplexy?

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

How does the brain process memories during sleep?

During sleep, the brain 'practices' recent experiences, thereby enhancing memory consolidation and recall.

What types of waves are predominantly associated with REM sleep?

The EEG during REM sleep resembles that of stage 1 sleep but is characterized by rapid eye movements.

What happens to synapses during REM sleep?

During REM sleep, redundant synapses are pruned, which helps in preserving newly formed synapses.

How does caffeine affect adenosine?

Caffeine blocks adenosine, a neuromodulator that promotes sleepiness and fatigue.

What is GABA's role in sleep?

GABA is a neurotransmitter that promotes sleep by inhibiting neuronal activity, reducing excitability.

How does the SCN influence melatonin production?

The SCN stimulates 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?

Sleep affects multiple systems including cardiovascular, immune, and metabolic functions.

How do sleep spindles relate to learning?

Sleep spindles increase in number after new learning, indicating their role in consolidating memories.

What is the paradox of lucid dreaming?

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

What is hypersomnia?

Hypersomnia is a sleep disorder characterized by excessive daytime sleepiness and prolonged nighttime sleep.

What is a common treatment for insomnia?

Common treatments for insomnia may include cognitive behavioral therapy, lifestyle changes, and medication.

What role does the hypothalamus play in sleep?

The hypothalamus regulates arousal, wakefulness, and sleep through various neurotransmitters.

What is the relationship between sleep and growth?

Sleep is vital for growth; adequate sleep is necessary for growth hormone release.

How can jet lag affect sleep patterns?

Jet lag 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?

Behavioral strategies 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)?

Their research demonstrated that the SCN is autonomous and can regulate circadian rhythms even when isolated.