U3: The Biological Bases of Behavior

Comprehensive vocabulary flashcards covering the biological bases of behavior, including genetics, the nervous system, neural firing, brain structures, and neuroimaging tools.

Nature vs. Nurture

The debate concerning how much of human behavior comes from life experiences (nurture) versus genetics (nature).

Evolutionary psychology

The study of how human behaviors and mental traits have evolved to help ancestors survive.

Behavior genetics

The study of how much genes and the environment influence overall behavior.

Environment

Everything surrounding an individual that can influence their development.

Heredity

The passing down of traits from parent to child through genes.

Genes

Segments of DNA that influence many physical and behavioral traits.

Genome

The complete set of genetic instructions in an organism.

Identical twins

Twins that develop when a single fertilized egg splits into two, resulting in shared genetic material.

Fraternal twins

Twins that develop when two separate eggs are fertilized to form two embryos in the womb.

Gene-environment interaction

The process by which genetic traits affect responses to the surrounding environment, and environmental factors influence how those traits develop.

Epigenetics

The study of how environmental factors can affect which genes are expressed without altering the underlying DNA sequence.

Central nervous system

The division of the nervous system consisting of the brain and spinal cord that processes information and controls bodily functions.

Peripheral nervous system

All the nerves outside of the brain and spinal cord that connect the central nervous system to the rest of the body.

Sensory neurons

Neurons that carry sensory information from receptor sites inward to the brain and spinal cord.

Motor neurons

Neurons that carry instructions from the central nervous system outward to the muscles and glands.

Interneurons

Neurons within the central nervous system that process incoming information and communicate between other neurons.

Somatic nervous system

The division of the peripheral nervous system that controls voluntary movements of skeletal muscles and relays sensory information to the central nervous system.

Autonomic nervous system

The division of the peripheral nervous system that regulates involuntary bodily processes such as breathing, heart rate, and internal functions.

Sympathetic nervous system

The division of the autonomic nervous system that triggers the fight, flight, or freeze response under stress.

Parasympathetic nervous system

The division of the autonomic nervous system that calms the body down and restores it to a resting state following stressful situations.

Reflexes

Automatic, unconscious physical responses to external stimuli.

Neuron

A specialized nerve cell that receives, processes, and sends electrical and chemical signals throughout the nervous system.

Cell body

The structural core of a neuron that houses the nucleus and maintains cellular functioning.

Dendrite

Branching extensions of a neuron that receive chemical and electrical signals from neighboring neurons.

Axon

A long fiber extending from a neuron that carries electrical impulses away from the cell body toward other cells.

Myelin sheath

A fatty layer insulating axon fibers that speeds up the transmission of electrical impulses.

Glial cells

Supportive cells in the nervous system that protect, nourish, and maintain neurons, while assisting in cognitive processes like thinking and memory.

Action potential

A brief electrical charge or impulse that travels down the axon of a neuron.

Threshold

The minimum intensity of stimulation required to trigger an action potential in a neuron.

Refractory period

The resting interval immediately following an action potential during which a neuron cannot fire again.

All-or-none response

The neural principle that a neuron fires at full strength or does not fire at all.

Synapse

The microscopic junction across which a neuron communicates with another neuron or target cell.

Neurotransmitters

Chemical messengers that cross synaptic gaps to influence the electrical and chemical activity of recipient cells.

Reuptake

The reabsorption of released neurotransmitters back into the presynaptic neuron from the synapse.

Acetylcholine

A neurotransmitter involved in motor control, muscle movement, learning, and memory.

Dopamine

A neurotransmitter involved in movement control, reward pathways, and motivation.

Serotonin

A neurotransmitter that regulates mood, sleep, and appetite, and is commonly associated with emotional well-being.

Norepinephrine

A neurotransmitter that plays a key role in alertness, sustained attention, and stress responses.

GABA

The primary inhibitory neurotransmitter in the brain that dampens neural excitability.

Glutamate

The primary excitatory neurotransmitter in the brain that increases neural firing and facilitates learning and memory.

Endorphins

Naturally occurring bodily chemicals that reduce pain perception and elevate feelings of pleasure.

Substance P

A chemical messenger and peptide involved in transmitting pain signals to the nervous system.

Agonist

A chemical or pharmacological substance that binds to a receptor to initiate a response or amplify the effects of a neurotransmitter.

Antagonist

A substance that binds to and blocks a receptor, inhibiting or reducing the typical effects of a neurotransmitter.

Endocrine system

A network of bodily glands that produce and secrete hormones into the bloodstream to regulate physiological processes.

Hormones

Chemical messengers manufactured by endocrine glands that travel through the circulatory system to influence distant target cells.

Biological psychologists

Researchers who investigate how the brain, nervous system, and genetic mechanisms influence human behavior and psychological processes.

Biopsychosocial approach

An integrated perspective that explains human behavior through interconnected biological, psychological, and social factors.

Neuroplasticity

The capacity of the nervous system to modify its structural organization and pathways in response to experience or damage.

Lesion

Localized structural damage or tissue destruction within the brain or nervous system.

EEG

Electroencephalogram; a diagnostic tool that uses surface electrodes on the scalp to detect and record electrical patterns of the brain.

MEG

Magnetoencephalography; an imaging technique that measures magnetic fields produced by electrical neural currents.

CT

Computed tomography; an imaging technique that compiles multiple X-ray cross-sections to generate detailed pictures of brain structures.

PET

Positron emission tomography; a neuroimaging technique using radioactive tracers to track metabolic and glucose consumption in active brain tissues.

FMRI

Functional magnetic resonance imaging; a technique that monitors blood oxygenation and flow to identify active brain structures.

Hindbrain

The lower portion of the brain containing structures that coordinate basic bodily functions, balance, and motor movements.

Midbrain

A central segment of the brainstem that assists with movement, alertness, and processing sensory inputs.

Forebrain

The most anterior and largest division of the brain, responsible for advanced cognition, sensory processing, emotion, and memory.

Brainstem

The core structure connecting the spinal cord to the forebrain that oversees automatic survival functions.

Medulla

The base of the brainstem regulating vital autonomic reflexes including heart rate, respiration, and blood pressure.

Thalamus

The sensory relay hub of the brain that routes sensory information toward destination areas in the cerebral cortex.

Reticular formation

A diffuse network of nerve pathways in the brainstem that modulates levels of arousal and wakefulness.

Cerebellum

A brain structure located at the rear of the brainstem that governs balance, posture, and motor coordination.

Limbic system

A neural network including the amygdala and hippocampus that controls emotional states, basic drives, and memory formation.

Amygdala

A limbic system structure that processes emotional responses, particularly threat detection and fear.

Hypothalamus

A limbic structure below the thalamus that maintains internal homeostasis and regulates basic drives like hunger and thirst.

Hippocampus

A neural center within the limbic system that facilitates the processing and consolidation of new memories into long-term storage.

Cerebral cortex

The outer convoluted mantle of neural tissue covering the cerebrum, responsible for advanced cognition, language, and sensory integration.

Frontal lobes

The anterior lobes of the cerebral cortex involved in executive functions, motor control, decision making, and personality.

Parietal lobes

Cerebral cortex lobes situated behind the frontal lobes that register and process tactile sensations.

Occipital lobes

The posterior regions of the cerebral cortex dedicated to receiving and processing visual sensory input.

Temporal lobes

The lateral regions of the cerebral cortex located near the ears that process auditory stimuli and assist in language comprehension.

Motor cortex

An area along the rear of the frontal lobe that directs voluntary skeletal muscle movements.

Somatosensory cortex

An area at the front of the parietal lobe that registers and processes bodily touch, temperature, and movement sensations.

Association areas

Cortical regions not directly dedicated to primary motor or sensory processing that synthesize and integrate complex information.

Corpus callosum

A dense collection of transverse nerve fibers connecting the left and right cerebral hemispheres, permitting interhemispheric communication.

Split brain research

Investigations conducted on individuals whose corpus callosum has been surgically severed, typically to manage severe epileptic seizures.