Psychology Block 3: The Nervous System, Brain Structure, and Neuropsychology

Vocabulary flashcards generated directly from lecture notes covering central and peripheral nervous system structures, neuronal electrophysiology, neurotransmitters, developmental stages, neuroplasticity, and neuroimaging modalities.

Central Nervous System (CNS)

The system composed of the brain and the spinal cord that processes and coordinates bodily functions, including thinking, moving, sensing, and regulating internal functions.

Spinal Cord

The structure protected inside the spinal column that acts as the primary communication highway between the brain and everything below the head.

Grey Matter

Tissue located on the inside of the spinal cord composed primarily of nerve cell bodies.

White Matter

Tissue surrounding grey matter on the outside of the spinal cord, consisting of insulated (myelinated) nerve fibres that facilitate fast signalling.

Cerebrospinal Fluid (CSF)

Fluid surrounding the brain that nourishes brain tissue and cushions it from physical impacts.

Meninges

Protective membranes surrounding the brain that store cerebrospinal fluid (CSF).

Hindbrain

The lowest and evolutionarily oldest division of the brain, sitting closest to the spinal cord with its cavity formed by the fourth ventricle.

Pons

A hindbrain structure containing cell clusters that regulate sleep and arousal and act as a relay station passing signals from the spinal cord to the brain.

Medulla Oblongata

The starting point of the brain connecting to the spinal cord, controlling essential unconscious functions such as breathing, muscle tone, and blood circulation.

Dysphagia

Difficulty swallowing, which can occur as a symptom of medulla oblongata dysfunction.

Cerebellum

Structure nicknamed the 'little brain' located behind and above the brain stem, crucial for coordinating movement, posture, equilibrium, and learned motor skills.

Reticular Formation

A neural network that originates in the hindbrain and extends into the midbrain, playing a key role in regulating alertness.

Midbrain

The brain division containing the cerebral aqueduct cavity, responsible for sensory processing and locating objects in space.

Forebrain

The largest, most complex, and evolutionarily newest brain division, whose fluid cavities consist of the lateral ventricles and third ventricle.

Thalamus

A forebrain structure that acts as a relay station, processing and relaying sensory information (except smell) to the cerebral cortex and regulating consciousness and arousal.

Hypothalamus

A forebrain structure controlling the pituitary gland to maintain homeostasis by regulating emotions, sleep, sexual activity, body temperature, hunger, and thirst.

Limbic System

A loosely connected network of brain structures involved in processing emotion, motivation, memory, learning, and self-preservation behaviours.

Amygdala

A limbic system structure involved in emotions, learning, emotional memory, aggression, and eating, drinking, and sexual behaviours.

Hippocampus

A key limbic system structure central to the formation and processing of memory.

Mammillary Bodies

Structures in the limbic system that serve as a relay station for episodic memory and sense of direction.

Korsakoff Syndrome

A chronic brain disorder causing severe memory impairment, stemming from a deficiency in vitamin B1 that damages the mammillary bodies.

Basal Ganglia

Brain structures involved in movement control; dysfunction within this system can cause Parkinson's disease.

Primary Areas

Cortical regions that directly receive and process raw sensory information arriving from sensory receptors via the thalamus.

Association Areas

Cortical regions responsible for integrating sensory inputs, processing complex mental functions, and giving meaning to information.

Frontal Lobe

The brain lobe responsible for voluntary movement, higher-order cognition, planning, decision-making, personality, and language production.

Primary Motor Cortex

The primary area of the frontal lobe that controls voluntary physical movements across various body parts.

Broca's Area

A region in the frontal lobe specialized for the physical production and expression of speech and language.

Broca's Aphasia

A language impairment caused by damage to Broca's area, characterized by severe difficulty producing spoken language.

Temporal Lobe

The brain lobe responsible for auditory processing, speech comprehension, memory acquisition, and object recognition.

Primary Auditory Cortex

The primary sensory area in the temporal lobe that processes fundamental sound characteristics, such as frequency and pitch.

Wernicke's Area

A temporal lobe structure dedicated to the comprehension and understanding of spoken language.

Prosopagnosia

A neurological condition resulting from temporal lobe dysfunction characterized by the inability to recognize familiar faces.

Wernicke's Aphasia

A language disorder caused by damage to Wernicke's area, resulting in difficulty understanding spoken language.

Parietal Lobe

The lobe responsible for processing tactile sensations, spatial orientation, body position awareness, and multi-sensory integration.

Primary Somatosensory Cortex

The primary region of the parietal lobe that processes sensory inputs from the body, including touch and bodily spatial position.

Agraphia

A parietal lobe dysfunction marked by an acquired inability or difficulty writing.

Alexia

A parietal lobe dysfunction marked by an acquired difficulty or inability to read.

Dyscalculia

A condition associated with parietal lobe dysfunction characterized by severe difficulty performing mathematical calculations.

Apraxia

A motor condition resulting from parietal lobe dysfunction where a person cannot execute purposeful movement despite having intact physical ability.

Occipital Lobe

The posterior cerebral lobe dedicated to receiving and processing visual information.

Primary Visual Cortex

The primary area of the occipital lobe that directly receives and processes elementary visual features.

Agnosia

An occipital lobe dysfunction defined by the inability to recognize or identify an object even though sensory information is intact.

Movement Agnosia

An impairment characterized by the specific inability to perceive or recognize the movement of objects.

Basal Nuclei

Subcortical structures comprising the caudate nucleus, putamen, and globus pallidus involved in motor planning, memory, and emotional expression.

Lateralisation

The functional specialization where certain mental or motor processes are controlled more dominantly by one hemisphere than the other.

Optic Chiasma

The anatomical junction where visual sensory pathways from each eye cross over to the contralateral cerebral hemisphere.

Wada Technique

A clinical procedure (Intracarotid Sodium Amobarbital procedure) used to evaluate the separate roles of each hemisphere in language and memory.

Right-Hemisphere Model

A model of emotional processing asserting that the right hemisphere is dominant for processing all types of emotions.

Valence Model

A model of emotional lateralisation asserting that the right hemisphere processes negative emotions while the left hemisphere processes positive emotions.

Hemispheric Specialization

The hemisphere-dependent association between specific cognitive, motor, or sensory functions and localized neural structures.

Sagittal Plane

An anatomical plane created by slicing the brain vertically into left and right sections.

Horizontal Plane

An anatomical plane created by slicing the brain horizontally into top and bottom sections.

Frontal Plane

An anatomical plane created by slicing the brain vertically into front and back sections (also called coronal plane).

Ontogenesis

The developmental lifespan process through which an organism grows and matures from a single fertilized egg into an adult.

Ectoderm

The outermost primary germ layer formed during gastrulation that develops into skin, hair, nails, sweat glands, and the entire nervous system.

Mesoderm

The middle primary germ layer that gives rise to muscles, bones, cartilage, connective tissue, and the cardiovascular and urogenital systems.

Endoderm

The innermost primary germ layer that lines the gastrointestinal tract and forms vital internal organs such as the lungs, liver, and pancreas.

Neurulation

The developmental process occurring during weeks 3 and 4 post-conception in which the embryonic neural tube forms and closes.

Corticogenesis

The formation of the cerebral cortex into six layers during embryonic weeks 6 and 7, following an inside-out pattern.

Arborization

The rapid growth and branching out of dendritic trees occurring from the embryonic phase up to approximately age 2.

Teratogens

External environmental agents or substances capable of causing structural or functional developmental abnormalities in an embryo or foetus.

Synaptic Pruning

The developmental process of eliminating excess or unused synaptic connections, removing approximately $40\%$ of all connections.

Somatic Nervous System

The peripheral division that conveys sensory input to the CNS and conducts motor commands to skeletal muscles for voluntary movement.

Autonomic Nervous System

The peripheral division controlling involuntary visceral organs, glands, and smooth muscles to preserve internal homeostasis.

Sympathetic Nervous System

The autonomic division responsible for activating energy reserves and preparing the body for action ('fight or flight').

Parasympathetic Nervous System

The autonomic division responsible for conserving energy and restoring the body to a calm, relaxed state.

Unipolar Neuron

A neuron extending a single process from the soma that later branches, primarily located in the spinal cord to carry sensory inputs like pain and temperature.

Bipolar Neuron

A sensory neuron with two distinct processes (an axon and a dendrite) extending from the soma, found in retina, cochlea, olfactory bulb, and tongue.

Multipolar Neuron

A neuron possessing one axon and numerous dendrites extending from the soma, commonly found in the cortex, cerebellum, and spinal cord for movement and cognition.

Axon Hillock

The conical junction connecting the neuronal soma to the axon, serving as the site where action potentials are initiated.

Myelin Sheath

An insulating lipid layer wrapped around axons that significantly speeds up electrical nerve impulse conduction.

Multiple Sclerosis

A neurological disorder characterized by progressive degradation of myelin sheaths, exposing nerve axons and disrupting signal transmission.

Resting State

The polarized membrane condition of an inactive neuron, maintaining a resting membrane potential of approximately $-70\,\text{mV}$.

Action Potential

A rapid, self-propagating electrochemical impulse conducted down an axon when the membrane potential reaches the threshold of excitation at $-55\,\text{mV}$.

Depolarization

The rapid influx of positive sodium ions ($\text{Na}^+$) through open channels, shifting membrane potential from negative up to roughly $+30\,\text{mV}$.

All-or-None Law

The principle stating that an action potential occurs at full amplitude or not at all once threshold is reached, regardless of stimulus intensity.

Absolute Refractory Period

A brief $1\text{--}2\,\text{millisecond}$ interval following an action potential during which the membrane cannot fire another impulse regardless of stimulus strength.

Synaptic Vesicles

Membrane-bound sacs located within presynaptic axon terminals that encapsulate and store neurotransmitters.

Reuptake

The presynaptic mechanism of reabsorbing unused neurotransmitter molecules from the synaptic cleft for recycling.

Excitatory Postsynaptic Potential (EPSP)

A temporary positive voltage shift in the postsynaptic membrane potential that increases the probability of an action potential.

Inhibitory Postsynaptic Potential (IPSP)

A temporary negative voltage shift in the postsynaptic membrane potential that decreases the probability of an action potential.

Dopamine

A key neurotransmitter involved in voluntary movement, mood, learning, and reward; dysfunctions are linked to Parkinson's disease, addiction, and mental disorders.

Norepinephrine

A neurotransmitter originating in the nucleus ceruleus involved in eating, sleep, arousal, emotion, attention, and memory speed.

Serotonin

A neurotransmitter originating in the raphe nuclei regulating sleep, arousal, mood, and appetite; dysfunctions are linked to depression and OCD.

Acetylcholine (ACh)

A neurotransmitter in the CNS and PNS mediating muscle action, learning, and memory, which undergoes degradation in Alzheimer's disease.

GABA (Gamma-Aminobutyric Acid)

The primary inhibitory neurotransmitter in the brain and spinal cord, responsible for reducing neural excitability across sleep and arousal pathways.

Glutamate

The principal excitatory neurotransmitter in the CNS; excessive concentration induces excitotoxicity that causes cell death.

Excitotoxicity

Pathological nerve cell damage or destruction resulting from overactivation of glutamate receptors.

Mesolimbic Pathway

A dopaminergic neural pathway mediating pleasure, motivation, perception, and reward-seeking behavior in addiction.

Endorphins

Endogenous peptide neurotransmitters distributed across the body that reduce pain perception and induce feelings of euphoria.

Agonist

A chemical agent that binds to a neurotransmitter receptor and mimics or enhances its natural biological effect.

Antagonist

A chemical agent that binds to a neurotransmitter receptor site and blocks or inhibits its normal physiological response.

Pituitary Gland

The master endocrine gland connected to the hypothalamus that directs hormone secretion across other systemic glands and controls physical growth.

Dynamic Localization

Luria's model proposing that complex cognitive processes are performed by integrated networks of distributed cortical sub-units working together.

Neuroplasticity

The structural and functional capacity of the nervous system to alter its neural pathways and synaptic organization in response to learning, environment, or injury.

Sensitive Periods

Developmental windows during which neural circuits display heightened sensitivity to environmental stimuli for normal maturation.

Cognitive Neuroscience

An interdisciplinary science linking theoretical models of cognitive psychology to underlying biological brain mechanisms.

Clinico-Anatomical Correlation

A historical neuroscientific method of attributing clinical symptoms observed in living patients to localized brain lesions found post-mortem.

Haemodynamic Response

The localized adjustment of blood volume and oxygen delivery to specific brain areas following increased neuronal firing.

Computed Tomography (CT)

A non-invasive structural neuroimaging technique using rotating X-ray beams to produce 2D cross-sectional brain images.