Biological Bases of Behavior Vocabulary

Comprehensive practice flashcards defining active vocabulary terms from the psychology review unit on the nervous system, brain structures, neurotransmitters, hormones, and psychoactive substances.

central nervous system (CNS)

The complex of nerve tissues consisting of the brain and spinal cord, which controls the activities of the body and processes information.

peripheral nervous system (PNS)

The division of the nervous system containing all nerves outside the central nervous system, connecting the brain and spinal cord to the rest of the body.

somatic nervous system

The division of the peripheral nervous system responsible for voluntary control of skeletal muscle movements.

autonomic nervous system

The division of the peripheral nervous system that regulates involuntary bodily functions, such as heart rate, digestion, and respiratory rate.

sympathetic nervous system

The branch of the autonomic nervous system that mobilizes the body during stressful situations, activating the 'fight-or-flight' response.

parasympathetic nervous system

The branch of the autonomic nervous system that calms the body and conserves energy, supporting 'rest-and-digest' functions.

sensory neuron

An afferent nerve cell that transmits impulses from sensory receptors toward the central nervous system.

interneuron

A neuron located entirely within the central nervous system that mediates communication between sensory and motor neurons.

motor neuron

An efferent nerve cell that conducts signals from the central nervous system to effectors, such as muscles and glands.

reflex arc

A direct neural pathway that controls an automatic, involuntary response to a sensory stimulus without immediate input from the brain.

multiple sclerosis

A chronic autoimmune disease in which the immune system destroys the myelin sheath surrounding axons, slowing or disrupting nerve impulses.

excitatory neurotransmitter

A chemical messenger that depolarizes the postsynaptic membrane, increasing the likelihood that the target neuron will fire an action potential.

inhibitory neurotransmitter

A chemical messenger that hyperpolarizes the postsynaptic membrane, decreasing the likelihood that the target neuron will fire an action potential.

agonist drug

A chemical substance that binds to a neural receptor and mimics or amplifies the biological action of a neurotransmitter.

antagonist drug

A chemical substance that binds to a neural receptor and blocks or impedes the normal action of a neurotransmitter.

reuptake inhibitor drug

A drug that prevents the reabsorption of neurotransmitters back into the presynaptic terminal, increasing their concentration in the synaptic cleft.

acetylcholine (ACh)

A neurotransmitter essential for voluntary muscle action, learning, and memory; its deterioration is strongly associated with Alzheimer's disease.

myasthenia gravis

An autoimmune neuromuscular disorder characterized by antibodies blocking or destroying acetylcholine receptors at neuromuscular junctions, leading to skeletal muscle weakness.

dopamine

A neurotransmitter involved in motor control, motivation, reward pathways, and emotional responses; excess is linked to schizophrenia, while depletion is linked to Parkinson's disease.

glutamate

The major excitatory neurotransmitter in the central nervous system, central to learning, memory formation, and synaptic plasticity.

GABA

Gamma-aminobutyric acid; the primary inhibitory neurotransmitter in the brain, responsible for reducing neuronal excitability.

endorphins

Endogenous opioid peptides produced in the brain that act as natural pain relievers and mood enhancers.

norepinephrine

A neurotransmitter and stress hormone that increases alertness, arousal, and vigilance during the fight-or-flight response.

serotonin

A neurotransmitter that regulates mood, appetite, sleep patterns, and emotional stability; undersupply is frequently linked to depressive disorders.

substance P

A neuropeptide neurotransmitter that transmits pain messages from sensory nerve fibers to the central nervous system.

medulla

The base structure of the brainstem that controls essential autonomic life-support functions, including heartbeat, respiration, and blood pressure.

reticular activating system

A diffuse network of nerve pathways in the brainstem that regulates arousal, wakefulness, consciousness, and attention.

thalamus

The brain's central sensory relay hub that processes and routes incoming sensory information (except smell) to specialized areas of the cerebral cortex.

cerebellum

A structure located at the rear of the brainstem that coordinates balance, posture, fine voluntary motor movements, and procedural memories.

hippocampus

A limbic system structure vital for processing and converting new explicit, conscious memories into long-term storage.

amygdala

Two almond-shaped clusters in the limbic system that play a primary role in processing emotional memories, particularly fear and aggression.

hypothalamus

A limbic structure below the thalamus that maintains homeostasis by regulating hunger, thirst, body temperature, and controlling the endocrine system via the pituitary gland.

frontal lobe

The anterior region of the cerebral cortex involved in higher-level executive functions, planning, reasoning, impulse control, and voluntary movement.

parietal lobe

The region of the cerebral cortex situated behind the frontal lobe that processes sensory information regarding touch, temperature, pressure, pain, and spatial awareness.

occipital lobe

The posterior region of the cerebral cortex responsible for receiving and processing visual stimuli from the eyes.

temporal lobe

The lateral region of the cerebral cortex located near the ears, containing auditory processing centers and areas critical for language comprehension.

association areas

Regions of the cerebral cortex that integrate sensory inputs and memories to enable higher cognitive processes such as thinking, problem-solving, and speaking.

Broca's aphasia

A non-fluent, expressive language disorder caused by damage to Broca's area, characterized by difficulty articulating speech while comprehension remains largely intact.

Wernicke's aphasia

A fluent, receptive language disorder caused by damage to Wernicke's area, where individuals speak in grammatically intact but meaningless sentences and struggle to comprehend language.

motor cortex

A strip of cerebral cortex situated at the rear of the frontal lobe that initiates and controls voluntary muscle movements throughout the body.

sensory (somatosensory) cortex

A region situated at the front of the parietal lobe that registers and processes tactile sensations such as touch, temperature, and body position.

lesion

A precise destruction or damage of brain tissue, resulting naturally from injury or disease, or induced experimentally to investigate brain function.

plasticity

The nervous system's capacity to modify its structural organization and functional connections in response to learning, experience, or neurotrauma.

EEG (Electroencephalogram)

A diagnostic recording technique that uses electrodes placed on the scalp to measure and track the brain's spontaneous electrical wave patterns.

fMRI (functional magnetic resonance imaging)

A neuroimaging technology that detects changes in blood oxygenation and flow to visualize active areas of the brain during specific tasks.

contralateral hemispheric organization

The physiological principle whereby each hemisphere of the cerebrum receives sensory input from and governs motor function on the opposite side of the body.

corpus callosum

A broad, thick band of myelinated nerve fibers connecting the left and right cerebral hemispheres, enabling interhemispheric communication.

leptin

A hormone produced by adipose tissue that acts on the hypothalamus to suppress appetite and signal energy satiety.

ghrelin

A hormone synthesized and secreted by the stomach lining that stimulates appetite and signals the brain to initiate food consumption.

oxytocin

A pituitary hormone involved in stimulating uterine contractions and milk ejection, which also fosters trust, social bonding, and maternal attachment.

tolerance

A state of decreased physiological or psychological responsiveness to a drug after repeated exposure, requiring increased amounts to achieve the initial effect.

withdrawal

The array of distressing physical and psychological symptoms experienced when an individual abruptly ceases or reduces the intake of an addictive substance.

depressant

A category of psychoactive substances (e.g., alcohol, barbiturates) that slows central nervous system activity and decreases bodily functions.

stimulant

A category of psychoactive substances (e.g., caffeine, nicotine, amphetamines) that accelerates neural activity and physiological arousal.

hallucinogen

A category of psychoactive drugs (e.g., LSD, psilocybin) that alters sensory perception, distorts thought processes, and produces vivid hallucinations.

opiate

A category of psychoactive drugs derived from the opium poppy (e.g., morphine, heroin) that dulls pain sensations and induces relaxation or euphoria by mimicking endorphins.