Neural & Endocrine Systems, Consciousness, Sleep, and Psychoactive Drugs

Comprehensive vocabulary flashcards reviewing neural and endocrine communication, consciousness, attention, sleep stages, brain structures, and psychoactive drug classes.

Nervous system

Body communication system that uses neurons and electrical-chemical signals for fast, precise, and short-term responses.

Endocrine system

Body communication system that uses glands to release hormones into the bloodstream for slower, broader, and longer-lasting effects.

Dendrites

Neuron structures that receive incoming messages.

Cell body

Part of the neuron that contains the nucleus and keeps the neuron alive.

Axon

Neuron fiber that carries signals away from the cell body.

Myelin sheath

Layer of fatty tissue that insulates the axon and speeds signal transmission.

Synapse

The junction or gap between neurons across which signals pass.

Neurotransmitters

Chemical messengers that cross the synapse to deliver signals to the next cell.

Hormones

Chemical messengers released into the bloodstream by endocrine glands.

Pituitary gland

Endocrine structure often called the 'master gland' that controls other endocrine glands.

Hypothalamus

Brain structure that links the nervous and endocrine systems, controls the pituitary gland, and helps regulate hunger, thirst, temperature, and emotions.

Epinephrine (adrenaline)

Hormone that triggers the fight-or-flight response.

Cortisol

A major stress hormone released by the endocrine system.

Insulin

Hormone that regulates metabolism by lowering blood sugar levels.

Melatonin

Hormone that regulates sleep-wake cycles.

Oxytocin

Hormone involved in social bonding, childbirth, and milk release.

Thyroxine

Hormone responsible for regulating overall body metabolism.

Consciousness

Awareness of yourself, your internal states, and your surrounding environment.

Selective attention

Focusing conscious awareness on one specific stimulus while ignoring others.

Divided attention

Attempting to split focus or attention across multiple tasks at the same time.

Inattentional blindness

Failing to notice an obvious, visible object or event because attention is directed elsewhere.

Change blindness

Failing to notice a change within a visual scene, often during a brief disruption or cut.

Automatic processing

Mental activity and thinking that occurs effortlessly and routinely with minimal conscious awareness.

Controlled processing

Deliberate, effortful, conscious thinking that requires focused attention.

Parallel processing

Handling multiple streams of information or tasks simultaneously.

Sequential processing

Processing information step-by-step in order, useful for complex or novel tasks.

Blindsight

A condition in which a person responds to visual stimuli without conscious awareness of seeing them, typically after visual cortex damage.

NREM-1

The lightest stage of sleep characterized by drifting off and easy awakening.

NREM-2

Deeper sleep stage featuring sleep spindles; the stage where most of the night is spent.

NREM-3

The deepest stage of slow-wave sleep, marked by delta waves and critical for physical restoration.

REM sleep

Rapid-eye-movement sleep stage marked by high brain activity, vivid dreaming, and muscle paralysis.

REM atonia

Temporary muscle paralysis occurring during REM sleep that prevents individuals from acting out their dreams.

Suprachiasmatic nucleus (SCN)

Brain structure acting as the master clock that uses light cues to regulate circadian rhythms.

Circadian rhythm

The internal 24-hour biological clock governing sleepiness, alertness, body temperature, and hormone release.

Beta waves

Brain rhythms associated with alert, active thinking.

Alpha waves

Brain rhythms associated with relaxed wakefulness.

Theta waves

Brain rhythms associated with drowsiness and light sleep.

Delta waves

Large, slow brain waves characteristic of deep NREM-3 sleep.

Activation-synthesis theory

Theory proposing that dreams are the brain's attempt to synthesize and make sense of random neural activity during sleep.

Cognitive theory of dreams

Theory proposing that dreams reflect ongoing information processing, daily concerns, and thinking.

Insomnia

Sleep disorder characterized by ongoing trouble falling asleep or staying asleep.

Narcolepsy

Sleep disorder characterized by sudden uncontrollable sleep attacks, sometimes accompanied by cataplexy.

Sleep apnea

Sleep disorder in which breathing repeatedly stops briefly during sleep, frequently accompanied by loud snoring.

Night terrors

Sleep disorder occurring during deep NREM sleep characterized by high arousal, terror, screaming, and little memory of the episode.

Sleepwalking

Motor behavior or walking during sleep, typically occurring during deep NREM sleep.

Cerebral cortex

The folded outer layer of the brain responsible for higher mental functions such as planning, thinking, perceiving, and voluntary movement.

Frontal lobes

Cortical lobes involved in planning, judgment, decision-making, personality, and voluntary motor movements.

Motor cortex

Region at the rear of the frontal lobe that controls voluntary movements in a topographically organized layout.

Prefrontal cortex

Frontal lobe area critical for executive functions, including impulse control, working memory, and goal setting.

Parietal lobes

Cortical lobes that process body sensations such as touch, pressure, pain, and temperature, and support spatial awareness.

Somatosensory cortex

Parietal lobe region that receives and interprets sensory information from body tissues.

Temporal lobes

Cortical lobes containing the auditory cortex, important for hearing, language processing, and memory.

Occipital lobes

Cortical lobes containing the visual cortex, responsible for processing incoming visual signals.

Association areas

Areas of the cerebral cortex that integrate sensory and motor information to enable higher-order thinking, language, learning, and memory.

Thalamus

Sensory relay station in the brain that routes incoming sensory information to appropriate cortical areas.

Limbic system

Neural system associated with emotion, motivation, and memory; includes the hippocampus and amygdala.

Hippocampus

Limbic system structure essential for processing and forming new memories.

Amygdala

Limbic system structure heavily involved in emotions, especially fear and aggression.

Brainstem

Central core of the brain responsible for autonomic survival functions like heartbeat, breathing, and arousal.

Cerebellum

Brain structure that coordinates balance, posture, fine voluntary movements, and motor learning.

Psychoactive drugs

Chemical substances that alter consciousness, mood, perception, and behavior by altering neurotransmission in the brain.

Depressants

Drug class that slows central nervous system and neural activity (e.g., alcohol, barbiturates, benzodiazepines).

Stimulants

Drug class that speeds up central nervous system activity, increasing alertness, energy, and heart rate (e.g., caffeine, nicotine, cocaine).

Opioids

Drug class that binds to endorphin receptors to relieve pain and induce euphoria, carrying a high risk of fatal respiratory depression.

Hallucinogens

Drug class that distorts perception and thought, evoking sensory experiences without sensory input (e.g., LSD, psilocybin, mescaline).

Tolerance

Diminishing effect with regular use of the same dose of a drug, requiring larger doses to experience the same effect.

Dependence

A state in which the body has adapted to a drug and functions less normally without its presence.

Withdrawal

The discomfort, distress, and unpleasant symptoms that follow discontinuing or reducing the use of an addictive drug.