Mammalian Physiology - Central Nervous System Vocabulary

Vocabulary flashcards covering key anatomical structures, pathways, conditions, and concepts of the central nervous system from BIO 305 Mammalian Physiology.

Gray Matter

Nervous tissue in the central nervous system consisting of short, nonmyelinated axons and neuron cell bodies.

White Matter

Nervous tissue in the central nervous system consisting primarily of myelinated axons in fiber tracts, whose color is derived from the dense fatty myelin coating.

Dorsolateral Prefrontal Cortex (DLPFC)

A subregion of the prefrontal cortex involved in working memory, planning, cognitive flexibility, and logical reasoning.

Ventromedial Prefrontal Cortex (VMPFC)

A subregion of the prefrontal cortex responsible for emotional regulation, integrating emotion into decision-making, and valuing outcomes.

Orbitofrontal Cortex (OFC)

A region of the prefrontal cortex responsible for impulse control, reward evaluation, social and moral judgment, and inhibiting inappropriate behavior.

Phineas Gage

A railroad worker who survived an iron tamping rod passing through his skull, suffering damage primarily to his ventromedial prefrontal cortex, which led to severe alterations in personality and impaired decision-making.

Somatosensory Cortex

Cortex responsible for processing touch, pressure, vibration, proprioception, pain, and temperature, as well as adjusting motor outputs such as grip force and posture.

Proprioception

The sensory perception of the position and movement of limbs in space.

Primary Motor Cortex

Cortical region located in the precentral gyrus critical for movement initiation, fine motor skills, postural coordination, and sending axon signals to specific skeletal muscles.

Premotor Area

Cortical region responsible for organizing movements before initiation, coordinating rhythmic movements, and facilitating transitions between sequential motor actions.

Supplementary Motor Area (SMA)

Region of the motor cortex involved in planning and executing sequential movements, particularly active during self-initiated actions that lack external cues.

Arcuate Fasciculus

An arched white matter tract that directly connects Broca's area to Wernicke's area; damage to this pathway causes conduction aphasia.

Superior Longitudinal Fasciculus

A major two-way white matter tract connecting the frontal, parietal, occipital, and temporal lobes; crucial for language, spatial attention, and motor coordination.

Uncinate Fasciculus

A hook-shaped white matter tract bridging the anterior temporal lobe and amygdala with the frontal cortex, essential for emotional regulation, memory, and social behavior.

Conduction Aphasia

A language deficit resulting from damage to the arcuate fasciculus or superior longitudinal fasciculus, characterized by intact comprehension and speech production, but an inability to repeat back heard speech.

Wernicke's Area

A region located near the auditory cortex in the left temporal lobe that is critical for language comprehension.

Blindsight

A condition resulting from damage to the primary visual cortex (V1) where patients experience cortical blindness in affected visual fields yet accurately guess or reach for visual targets above chance via alternative subcortical visual pathways.

Serotonin 2A Receptor ($5\text{-HT}_{2A}$)

A receptor densely expressed in visual, associative, and prefrontal areas where psychedelic agonists like LSD, psilocybin, and DMT bind to produce subjective perceptual effects.

Basal Ganglia

A group of subcortical nuclei—including the caudate, putamen, globus pallidus, substantia nigra, and subthalamic nucleus—involved in movement initiation, habit formation, procedural learning, and reward.

Parkinson's Disease

A progressive neurodegenerative disorder caused by the loss of dopamine-producing neurons in the substantia nigra, resulting in tremor, rigidity, bradykinesia, and akinesia.

Bradykinesia

Slowness of movement, a cardinal motor symptom of Parkinson's disease.

Akinesia

The loss or reduction of voluntary movement ability.

Thalamus

The diencephalic structure that acts as the brain's major sensory relay station, transmitting nearly all sensory input except smell to the cerebral cortex while regulating consciousness and alertness.

Midbrain

The upper portion of the brainstem that acts as a relay for visual and auditory reflexes via the superior and inferior colliculi, contains the substantia nigra, and regulates arousal.

Pons

The brainstem structure serving as a bridge between the cerebrum, cerebellum, and spinal cord; involved in REM sleep, cranial nerve relay, and regulating breathing rhythm alongside the medulla.

Medulla Oblongata

The lower brainstem region controlling vital autonomic functions such as heart rate, blood pressure, and breathing, and housing reflex centers for coughing, swallowing, and vomiting.

Locked-in Syndrome

A condition caused by damage to the ventral pons (often due to basilar artery occlusion) where a patient remains fully conscious but experiences complete paralysis except for vertical eye movements and blinking.

Jean-Dominique Bauby

A patient with locked-in syndrome who composed his memoir, 'The Diving Bell and the Butterfly', by blinking his left eyelid to select letters.

Cerebellum

Structure located posterior to the brainstem that fine-tunes motor coordination, balance, posture, motor learning, and precise timing of multi-muscle actions.

Amygdala

An almond-shaped limbic structure in the temporal lobe responsible for fear processing, threat detection, emotional memory, and tagging experiences with emotional weight.

Urbach-Wiethe Disease

A rare genetic disorder causing calcification and degeneration of the amygdala, leading to an inability to feel fear or recognize fearful facial expressions.

Nucleus Accumbens

A structure in the ventral striatum that serves as a central reward hub, receiving dopaminergic input from the ventral tegmental area (VTA) to signal reward reinforcement.

GLP-1 Receptor Agonists

Medications that mimic Glucagon-Like Peptide-1, binding GLP-1 receptors on VTA dopamine neurons in the brain to reduce appetite, slow gastric emptying, and alter reward-seeking behavior.

Long-Term Potentiation (LTP)

A persistent increase in synaptic strength following high-frequency stimulation, electrophysiologically identified by an increased AMPAR/NMDAR ratio.

Long-Term Depression (LTD)

A persistent reduction in synaptic strength where synapses become weaker over extended periods.

Amyotrophic Lateral Sclerosis (ALS)

A progressive motor neuron disease that selectively degenerates upper and lower motor neurons controlling voluntary muscles while leaving sensation, cognition, and consciousness intact.

Phrenic Nerve

A motor nerve originating from spinal segments $C3\text{-}C5$ that innervates the diaphragm to control breathing.