Reticular Activating System, Sleep, and Circadian Rhythms

A comprehensive set of vocabulary flashcards related to the reticular activating system, various states of sleep, and associated neurological processes.

Reticular Activating System

A diffuse projection system in the brain that controls the general level of excitability of the cerebral cortex.

Circadian Rhythm

A biological clock that regulates the sleep-wake cycle approximately every 24 hours.

NREM Sleep

Non-rapid eye movement sleep; includes stages N1 to N4 and is characterized by synchronized EEG activity.

REM Sleep

Rapid eye movement sleep, also known as paradoxical sleep, associated with desynchronized EEG activity and vivid dreams.

Glasgow Coma Scale

A scale used to assess consciousness level in patients with brain injury based on eye, verbal, and motor responses.

Comatose State

A prolonged state of unresponsiveness often caused by brain damage.

Persistent Vegetative State

A condition where higher cortical centers are non-functional but brainstem activity allows sleep-wake cycles.

EEG (Electroencephalogram)

A recording of the electrical activity of the brain used to analyze brainwave patterns.

Secondary Recruiting Response

The increased amplitude of neuronal response associated with the diffuse projection system.

Primary Evoked Response

The electrical response from sensory stimuli within 7 msec, linked to the specific projection systems.

Afferent Input

Sensory or internal signals that can influence levels of consciousness and excitability.

Delta Rhythm

Low frequency, high amplitude brain wave activity associated with deep sleep.

Theta Rhythm

Brain wave oscillation of 4-7 Hz, generally associated with drowsiness and light sleep.

Alpha Rhythm

Brain wave activity of 8-13 Hz typically observed in awake resting states with eyes closed.

Beta Rhythm

Higher frequency brain waves of 14-30 Hz, associated with alert and active mental states.

Cholinergic Neurons

Neurons that use acetylcholine as a neurotransmitter, active during wakefulness and REM sleep.

Parasomnia

Abnormal behavior occurring during sleep, including sleepwalking and night terrors.

Insomnia

Difficulty sleeping, affecting millions of individuals.

Narcolepsy

A condition characterized by sudden uncontrollable sleep attacks, often starting with REM sleep.

Sleep Apnea

A disorder where breathing repeatedly stops and starts during sleep due to airway obstruction.

SIDS (Sudden Infant Death Syndrome)

The unexplained death of an otherwise healthy infant during sleep, often occurring under one year of age.

Sleep Cycle

The progression through various stages of sleep, typically lasting about 90 minutes.

Melatonin

A hormone produced by the pineal gland that regulates sleep-wake cycles, increasing at night.

Sleep Stages N1 to N4

Stages of sleep marked by varying levels of consciousness and brain wave activity from light to deep sleep.

Selective Excitation and Inhibition

The process by which certain neural pathways are activated or suppressed to control neural responses.

Neuronal Oscillations

Fluctuations in electrical activity in the brain associated with cognitive states.

GABAergic Inhibition

Inhibition in neuronal activity mediated by GABA neurotransmitter, playing a key role in sleep regulation.

Atonia

Loss of muscle tone, particularly during REM sleep, preventing physical movement during dreams.

Hyposomnia

Abnormally decreased amount of sleep or excessive daytime sleepiness.

Genetic Channel Defects

Mutations in ion channel genes that can lead to increased neuronal excitability and conditions like epilepsy.

Cataplexy

A sudden loss of muscle tone that can occur in narcolepsy, often triggered by strong emotions.

Stupor

A near-unconscious state where a person can only be aroused with strong stimuli.

Encephalitis

Inflammation of the brain often leading to altered consciousness or comatose states.

Body Temperature Regulation

Physiological processes influenced by circadian rhythms, particularly affected by melatonin.

Thalamocortical System

The system connecting the thalamus and cortex, crucial for sensory perception and consciousness.

Behavioral State

Different levels of consciousness that can be modulated by various internal and external factors.

Neural Pathways

Connections between neurons that transmit signals throughout the nervous system.

Omega-3 Fatty Acids

Essential nutrients that play roles in brain health, potentially aiding in sleep regulation.

What are brain waves and brain oscillations?

Brain waves and brain oscillations refer to the electrical activities produced by the brain, which can be recorded from the skull or skin using electrodes.

What is the typical voltage range for brain activity recordings?

The voltage recorded from brain activity is typically in the millivolt range.

What happens to voltage as it passes through the skull?

The voltage decreases by a thousand-fold as it goes through the skull.

What are comas in relation to brain activity?

Comas can sometimes last for a shorter period of time and are related to the activity levels in the brain.

What controls the excitability of the brain?

The excitability of the brain is controlled by the reticular activating system.

How does brain activity relate to oscillation characteristics?

The busier the brain is, the faster the frequency of the oscillations and the lower the amplitude.

What is the standard frequency that drives the whole brain system?

The standard frequency is the 12-15 Hz alpha rhythm.

How can overexcitability of nerve cells affect brain function?

Overexcitability of nerve cells can lead to conditions like epilepsy, which has two types that are important to recognize.

Why should individuals with epilepsy avoid driving?

Individuals with either type of epilepsy should not be driving due to the risk of seizures.