Localization of Brain Function & Neurotransmission – Vocabulary Review

These flashcards present core vocabulary from the lecture on nervous-system organization, brain structures, language areas, reflexes, emotion circuitry, neuron anatomy, neurotransmission, and related neurological disorders.

Central Nervous System (CNS)

Comprises the brain and spinal cord; processes sensory input and sends commands to the body.

Peripheral Nervous System (PNS)

Network of nerves outside the CNS that relays messages between the body and the brain; includes somatic and autonomic divisions.

Somatic Nervous System

Subdivision of the PNS that controls voluntary muscle movements and carries sensory information to the CNS.

Autonomic Nervous System

PNS subdivision controlling involuntary functions via sympathetic and parasympathetic branches.

Sympathetic Nervous System

Autonomic branch that heightens arousal for the fight-flight-freeze response.

Parasympathetic Nervous System

Autonomic branch that calms the body and maintains homeostasis.

Brain

Organ responsible for interpretation, thought, muscle control, behaviour, sensation–motor coordination, and personality.

Spinal Cord

Bundle of nerve fibres connecting the PNS to the brain; site of reflexes and conduit for sensory-motor signals.

Spinal Reflex

Innate, rapid response to sensory stimuli processed within the spinal cord without conscious thought.

Monosynaptic Reflex Arc

Reflex pathway with one synapse: sensory neuron directly to motor neuron.

Polysynaptic Reflex Arc

Reflex pathway with at least one interneuron between sensory and motor neurons.

Cerebrum

Largest brain portion (left & right hemispheres) handling higher-order thinking and localized sensory functions.

Cerebellum

Structure beneath cerebrum that coordinates muscle movement, posture, and balance.

Brain Stem

Controls vital involuntary functions (breathing, heart rate, temperature, sleep) and relays information between brain regions and body.

Cerebral Cortex

Outer layer of cerebrum divided into four lobes; key for conscious thought and sensory processing.

Frontal Lobe

Largest cortical lobe; governs speech, abstract thought, planning, social skills, and houses the primary motor cortex.

Temporal Lobe

Processes auditory information; contains the primary auditory cortex.

Parietal Lobe

Perceives space, shapes, object location; holds the primary somatosensory cortex.

Occipital Lobe

Processes visual input; contains the primary visual cortex.

Association Areas

Cortical regions integrating information beyond primary sensory/motor functions for complex tasks like thinking and memory.

Broca’s Area

Left frontal-lobe region responsible for fluent speech production.

Wernicke’s Area

Left temporal-lobe region essential for speech comprehension.

Geschwind’s Territory

Parietal-temporal-frontal junction linking Broca’s and Wernicke’s areas to integrate language processing.

Aphasia

Language impairment affecting speaking, comprehension, reading, or writing; can stem from stroke or neuro-disease.

Basal Ganglia

Hindbrain nuclei that plan voluntary movement goals and inhibit competing actions.

Limbic System

Emotion-processing network comprising hippocampus, amygdala, and hypothalamus.

Hippocampus

Limbic structure aiding emotion regulation and memory recall (‘slow, thinking high road’).

Amygdala

Almond-sized limbic structure that triggers emotional reactions and stores emotional memories (‘quick, low road’).

Hypothalamus

Regulates physiological fear responses via the HPA axis and maintains internal balance.

Prefrontal Cortex

Frontal cortical area that evaluates, regulates, and changes emotions and guides decision making.

Neuron

Nerve cell that communicates via electro-chemical signals.

Dendrite

Branching neuron part that receives information and channels it to the soma.

Soma (Cell Body)

Neuron part controlling metabolism and maintenance.

Axon

Long fibre carrying the nerve impulse away from the soma.

Myelin

Protective sheath around axons preventing interference and speeding impulses.

Axon Terminals

End branches releasing neurotransmitters into the synapse.

Neurotransmitter

Chemical messenger that transmits signals between neurons across a synapse.

Synapse

Microscopic gap between neurons where neurotransmission occurs.

Lock-and-Key Process

Mechanism where a neurotransmitter binds only to matching postsynaptic receptors to pass the message.

Excitatory Synapse

Connection that increases the likelihood the postsynaptic neuron will fire (e.g., glutamate).

Inhibitory Synapse

Connection that decreases the likelihood the postsynaptic neuron will fire (e.g., GABA).

Glutamate

Primary excitatory neurotransmitter involved in learning and memory.

Gamma-Amino Butyric Acid (GABA)

Chief inhibitory neurotransmitter; regulates anxiety by reducing neuronal firing.

Action Potential

Brief electrical charge (depolarizing spike) that travels down the axon when a neuron fires.

Acetylcholine (ACh)

Neurotransmitter enabling muscle action, learning, memory, REM sleep; deficits linked to Alzheimer’s.

Epinephrine (Adrenaline)

Hormone/neurotransmitter released in stress; raises heart rate, blood pressure, respiration.

Norepinephrine

Hormone/neurotransmitter that heightens alertness and arousal; influences mood and concentration.

Dopamine

Neurotransmitter tied to pleasure, motivation, learning, and movement; deficits relate to Parkinson’s and depression.

Serotonin

‘Feel-good’ neurotransmitter regulating mood, sleep, appetite, and social behaviour; low levels linked to depression.

Alzheimer’s Disease

Neurodegenerative disorder marked by acetylcholine loss, plaques, tangles, and progressive memory decline.

Parkinson’s Disease

Movement disorder caused by dopamine-producing cell loss in the substantia nigra of the basal ganglia.