OpenStax Chapter 4 States of Consciousness

central sleep apnea

sleep disorder with periods of interrupted breathing due to a disruption in signals sent from the brain that regulate breathing

consciousness

awareness of internal and external stimuli

depressant

drug that tends to suppress central nervous system activity

hallucinogen

one of a class of drugs that results in profound alterations in sensory and perceptual experiences, often with vivid hallucinations

homeostasis

tendency to maintain a balance, or optimal level, within a biological system

hypnosis

state of extreme self-focus and attention in which minimal attention is given to external stimuli

insomnia

consistent difficulty in falling or staying asleep for at least three nights a week over a month's time

meditation

clearing the mind in order to achieve a state of relaxed awareness and focus

melatonin

hormone secreted by the endocrine gland that serves as an important regulator of the sleep-

wake cycle

narcolepsy

sleep disorder in which the sufferer cannot resist falling to sleep at inopportune times

night terror

sleep disorder in which the sleeper experiences a sense of panic and may scream or attempt

to escape from the immediate environment

obstructive sleep apnea

sleep disorder defined by episodes when breathing stops during sleep as a result of blockage of the airway

parinsomnia

one of a group of sleep disorders characterized by unwanted, disruptive motor activity and/or experiences during sleep

physical dependence

changes in normal bodily functions that cause a drug user to experience withdrawal symptoms upon cessation of use

pineal gland

endocrine structure located inside the brain that releases melatonin

psychological dependence

emotional, rather than a physical, need for a drug which may be used to relieve psychological distress

restless leg syndrome

sleep disorder in which the sufferer has uncomfortable sensations in the legs when trying to fall asleep that are relieved by moving the legs

sleep debt

result of insufficient sleep on a chronic basis

sleep rebound

sleep-deprived individuals will experience longer sleep latencies during subsequent opportunities for sleep

sleep regulation

brain's control of switching between sleep and wakefulness as well as coordinating this cycle with the outside world

sleep

state marked by relatively low levels of physical activity and reduced sensory awareness that is distinct from periods of rest that occur during wakefulness

stimulant

drug that tends to increase overall levels of neural activity; includes caffeine, nicotine, amphetamines, and cocaine

sudden infant death syndrome (SIDS)

infant (one year old or younger) with no apparent medical condition suddenly dies during sleep

tolerance

state of requiring increasing quantities of the drug to gain the desired effect

wakefulness

characterized by high levels of sensory awareness, thought, and behavior

withdrawal

variety of negative symptoms experienced when drug use is discontinued