Chapter 12_Sleep and the Circadian Rhythm Flashcards
Polysomnogram
A comprehensive recording of physiological changes during sleep, including EEG, eye movement, and muscle activity.
Somnambulism
Sleepwalking; performing activities typically associated with wakefulness while asleep.
Electroencephalography (EEG)
A method to measure electrical activity in the brain, commonly used to monitor sleep stages.
Rapid Eye Movement (REM)
A sleep phase characterized by rapid eye movements and vivid dreaming, also known as paradoxical sleep.
REM Sleep
The sleep stage associated with rapid eye movement, high brain activity, and vivid dreams.
Non-REM Sleep (NREM)
Sleep stages without rapid eye movements, including NREM1, NREM2, and NREM3, progressing from light to deep sleep.
NREM1
The lightest stage of NREM sleep, marked by a transition from wakefulness to sleep.
NREM2
A deeper NREM sleep stage with the appearance of sleep spindles and K-complexes on an EEG.
NREM3
The deepest NREM sleep stage, also called slow-wave sleep, characterized by delta waves.
K-complexes
Large amplitude brain waves in NREM2, potentially involved in memory and sleep protection.
Sleep Spindle
Short bursts of high-frequency brain waves during NREM2, thought to play a role in memory consolidation.
Paradoxical Sleep
Another term for REM sleep, where the brain is active despite physical relaxation.
Hypnogram
A graphical representation of the stages of sleep across a sleep period.
Recuperation Theory
A theory suggesting that sleep allows the body and brain to repair and restore energy.
Glymphatic System
A system that clears waste from the brain, believed to be active during sleep.
Beta-Amyloid
A protein that accumulates in the brain and is associated with Alzheimer’s disease, removed more effectively during sleep.
Growth Hormone (GH)
A hormone that promotes growth and cell repair, released in higher amounts during deep sleep.
Evolutionary Adaptation Theory
Suggests that sleep patterns evolved to protect organisms during vulnerable times, such as nighttime for humans.
Brain Plasticity Theory
A theory proposing that sleep aids brain development and learning by strengthening neural connections.
Declarative Memory
Memory of facts and events, strengthened by slow-wave sleep.
Procedural Memory
Memory of skills and actions, often improved by REM sleep.
Circadian Rhythm
A 24-hour biological cycle that regulates sleep-wake patterns and other physiological processes.
Jet Lag
Disruption of circadian rhythms due to travel across time zones.
Entrainment
Adjustment of the internal clock to external cues, such as light.
Zeitgebers
External cues, like light and temperature, that help set the circadian rhythm.
Sedatives and Sleep Aids
Medications that promote sleep by enhancing inhibitory neurotransmitter activity, often affecting GABA.
Glutamatergic Signaling
Activity involving the neurotransmitter glutamate, which promotes wakefulness and cognitive activity.
Adenosine
A molecule that builds up during wakefulness, promoting sleepiness; its effects can be blocked by caffeine.
Caffeine
A stimulant that blocks adenosine receptors, reducing feelings of sleepiness.
Melatonin
A hormone released by the pineal gland that promotes sleep, especially in response to darkness.
Pineal Gland
A small brain structure that produces melatonin, helping to regulate sleep-wake cycles.
Retinohypothalamic Tract (RHT)
A pathway that conveys light information from the retina to the suprachiasmatic nucleus, influencing circadian rhythms.
Suprachiasmatic Nucleus (SCN)
A brain region in the hypothalamus that acts as the body’s master clock, regulating circadian rhythms.
Histamine
A neurotransmitter that promotes wakefulness, also involved in immune responses.
Hypothalamus
A brain region involved in regulating sleep, wakefulness, and other homeostatic functions.
Encephalitis Lethargica
A historical illness causing extreme sleep disturbances, contributing to understanding of sleep mechanisms in the hypothalamus.
Reticular Formation
A network of neurons in the brainstem involved in maintaining alertness and regulating the sleep-wake cycle.
Orexin
A neurotransmitter that promotes wakefulness; loss of orexin-producing cells is linked to narcolepsy.
Insomnia
A sleep disorder characterized by difficulty falling or staying asleep, leading to impaired daytime functioning.
Onset Insomnia
Difficulty falling asleep at the beginning of the night.
Maintenance Insomnia
Difficulty staying asleep or waking up too early and being unable to return to sleep.
Iatrogenic Insomnia
Insomnia caused by medical treatment or prolonged use of sleep medications.
Sleep Apnea
A sleep disorder where breathing repeatedly stops and starts, leading to fragmented sleep.
Obstructive Sleep Apnea
A form of sleep apnea caused by airway blockage due to relaxed throat muscles.
Central Sleep Apnea
A form of sleep apnea resulting from the brain failing to signal muscles to breathe.
CPAP Device
A machine that provides continuous positive airway pressure to keep the airway open in sleep apnea patients.
Narcolepsy
A sleep disorder characterized by excessive daytime sleepiness and sudden sleep attacks.
Cataplexy
A sudden loss of muscle tone triggered by strong emotions, often seen in narcolepsy.
Restless Legs Syndrome
A condition causing uncomfortable leg sensations, typically relieved by movement, often worse at rest.
Periodic Limb Movement Disorder
Involuntary limb movements during sleep, often disrupting sleep patterns.
