Nervous System and Behavioral Neuroscience Vocabulary

Vocabulary flashcards covering the biology of psychology, neuron anatomy, action potentials, neurotransmitters, nervous system divisions, reflex arcs, cerebral cortex structure, and language processing.

Reticular Theory

Historical theory popularized by Camillo Golgi stating that the nervous system is composed of one continuous, interconnected network of tissue.

Neuron Theory

Theory championed by Santiago Ramón y Cajal proposing that the nervous system is made of separate, individual cells called neurons that communicate with each other.

Types of Neurons

Structural and functional classifications of neural cells, including sensory neurons (unipolar), motor neurons (multipolar), pyramidal neurons, astrocytes, Betz cells, and microglia.

Synaptic Pruning

Process following a "use it or lose it" principle where the brain removes infrequently used synapses to increase energy efficiency and tailor neural networks to an individual's environment.

Dendrites

Branch-like extensions of a neuron that primarily receive incoming chemical and electrical signals from other neurons.

Cell Body

Central portion of a neuron containing the nucleus that supports the cell's basic biological functions.

Axon Hillock

The junction between the cell body and the axon that sums incoming electrical signals and determines whether an action potential will fire.

Axon

Long, slender extension of a neuron that conducts electrical impulses away from the cell body toward the synaptic terminals.

Myelin Sheath

Fatty covering surrounding sections of many axons that speeds up the transmission of action potentials.

Synaptic Terminals

Endings at the tip of an axon that release neurotransmitters across the synaptic gap.

Resting Potential

The stable electrical charge difference across a cell membrane when a neuron is not firing, measured at $-70\,mV$.

Threshold

The critical voltage level of approximately $-55\,mV$ that a cell membrane must reach at the axon hillock to trigger an action potential.

Action Potential

A rapid, temporary change in electrical voltage across a cell membrane reaching $+40\,mV$, triggered by sodium ions ($\text{Na}^+$) entering the axon, allowing excitable cells to communicate.

All-or-None Principle

Rule stating that a neuron either fires completely or does not fire at all, with no variation in the strength or size of individual action potentials.

Saltatory Transmission

Process in which electrical signaling rapidly "jumps" from one gap in the myelin sheath to the next, significantly accelerating signal velocity.

C Fibers

Unmyelinated nerve fibers that conduct slow, dull, throbbing pain signals at a speed of approximately $2\,mph$.

A-delta Fibers

Lightly myelinated nerve fibers that conduct sharp pain signals at a speed of approximately $25\,mph$.

A-beta Fibers

Moderately myelinated nerve fibers that transmit touch and pressure sensations at a speed of approximately $120\,mph$.

A-alpha Fibers

Heavily myelinated nerve fibers responsible for proprioception, transmitting position sense at speeds between $225\,mph$ and $270\,mph$.

Multiple Sclerosis

Chronic autoimmune disorder in which the immune system attacks the myelin sheath, causing demyelination and slowing signal transmission.

Agonist

Substance or drug that binds to and activates receptor sites, mimicking or enhancing the action of naturally occurring neurotransmitters.

Antagonist

Substance or drug that binds to receptor sites and blocks them, preventing endogenous neurotransmitters from binding or activating the receptor.

Buprenorphine

Therapeutic medication used for managing opioid addiction that acts as a partial opioid agonist and a powerful antagonist to ease withdrawal and lower relapse risk.

Dopamine

Neurotransmitter involved in cognition, movement, motivation, sleep, mood, and attention; deficient in Parkinson's disease and overactive in schizophrenia.

Reuptake

Cellular process in which neurotransmitters remaining in the synaptic gap are recycled back into the presynaptic neuron via transporter proteins.

Reuptake Inhibitor

Class of drugs that block neurotransmitter transporters, keeping higher concentrations of neurotransmitters in the synaptic gap to prolong receptor binding.

Divisions of the Nervous System

The overall structural organization of the nervous system into Central (brain and spinal cord) and Peripheral branches, with Peripheral further split into Autonomic and Somatic systems.

Somatic Nervous System

Part of the peripheral nervous system that controls voluntary muscle movement and connects sense organs to the central nervous system.

Autonomic Nervous System

Division of the peripheral nervous system regulating involuntary, automatic functions of internal organs and glands through sympathetic and parasympathetic branches.

Afferent Pathways

Sensory nerve pathways that carry signals upward and inward from body receptors to the central nervous system.

Efferent Pathways

Motor nerve pathways that transmit commands downward and outward from the central nervous system to muscles and target organs.

Sympathetic Division

Subsystem of the autonomic nervous system that mediates the "fight or flight" response, increasing heart rate, dilating airways, and inhibiting digestion.

Parasympathetic Division

Subsystem of the autonomic nervous system governing "rest and digest" and "feed and breed" functions, slowing heart rate and promoting digestion during relaxed states.

Patellar Reflex

A spinal reflex arc elicited by tapping the patellar tendon that causes leg extension to prevent an individual from falling backward.

Withdrawal Reflex

Automatic spinal reflex pathway that causes rapid contraction of muscles to pull a limb away from painful or damaging stimuli.

Cerebral Cortex

The outer layer of grey matter covering the cerebrum, divided into two hemispheres and four major lobes containing sulci and gyri.

Frontal Lobe

Major lobe of the cerebral cortex involved in reasoning, planning, movement, speech production, emotions, and problem solving.

Parietal Lobe

Region of the cerebral cortex associated with processing touch, spatial orientation, movement perception, and sensory recognition.

Occipital Lobe

Posterior region of the cerebral cortex dedicated primarily to receiving and processing visual information.

Temporal Lobe

Cortical region involved in processing auditory information, language comprehension, memory, and speech recognition.

Phrenology

Discredited pseudoscience claiming that personality traits and mental faculties can be determined by measuring bumps on the skull.

Geschwind-Wernicke Theory of Language

Model outlining the sequential pathway of language processing through the auditory cortex, Wernicke's area, Broca's area, and the motor cortex.

Wernicke's Area

Left-hemisphere cortical region responsible for comprehending spoken and written language and formulating basic response ideas.

Broca's Area

Left-hemisphere cortical area that organizes language ideas into a grammatically structured sentence and speech plan.

Wernicke's Aphasia

Language disorder resulting from damage to Wernicke's area, characterized by fluent but meaningless speech, word substitutions, and severe comprehension deficits.

Broca's Aphasia

Language impairment caused by damage to Broca's area, resulting in slow, halting, and effortful speech output while comprehension remains largely intact.

Contralateral Control

Neural arrangement where each cerebral hemisphere primarily regulates motor output and processes sensory inputs from the opposite side of the body.

Corpus Callosum

Dense nerve tract connecting the left and right cerebral hemispheres, enabling communication and information sharing between them.

Prosopagnosia

Neurological condition commonly referred to as "face blindness," marked by an inability to recognize familiar faces while general vision and intelligence remain normal.

Fusiform Face Area

Neural region located in the brain, particularly in the right hemisphere, specialized for facial recognition and visual processing of faces.