Brain and Cranial Nerves – Vocabulary Flashcards

A comprehensive set of vocabulary flashcards covering key brain structures, protective mechanisms, functional centers, and cranial nerves from the Chapter 14 lecture notes.

Cerebrum

Largest brain region; responsible for conscious thought, intellect, memory, and voluntary motor control.

Cerebellum

Second-largest brain region; coordinates posture and fine-tunes conscious and subconscious movements.

Diencephalon

Region including thalamus, hypothalamus, and epithalamus; integrates sensory input with motor output.

Brainstem

Collective term for midbrain, pons, and medulla oblongata; relays information between spinal cord and higher centers.

Cerebral Cortex

Surface layer of gray matter covering the cerebrum; site of higher processing.

Gyri

Raised folds on the cerebral cortex that increase surface area for neurons.

Sulci

Shallow grooves separating adjacent gyri on the cerebral surface.

Fissures

Deep grooves that divide large brain regions or lobes.

Thalamus

Major relay center that filters and directs sensory information to the cerebral cortex.

Hypothalamus

Autonomic and endocrine control center; regulates temperature, hunger, circadian rhythms, and hormone release.

Pituitary Gland

Endocrine gland attached to hypothalamus via infundibulum; secretes multiple hormones.

Midbrain (Mesencephalon)

Processes visual and auditory reflexes and helps maintain consciousness.

Pons

Links cerebellum to rest of brain; houses respiratory nuclei and cranial nerve nuclei V–VIII.

Medulla Oblongata

Lowest part of brainstem; contains autonomic centers for cardiovascular, respiratory, and digestive control.

Prosencephalon

Embryonic forebrain from which telencephalon and diencephalon develop.

Mesencephalon

Embryonic midbrain that persists as the adult midbrain.

Rhombencephalon

Embryonic hindbrain that forms metencephalon and myelencephalon.

Telencephalon

Secondary brain vesicle that becomes the cerebral hemispheres.

Metencephalon

Secondary brain vesicle that forms the pons and cerebellum.

Myelencephalon

Secondary brain vesicle that develops into the medulla oblongata.

Ventricle

CSF-filled chamber within the brain lined by ependymal cells.

Lateral Ventricles

Paired ventricles within cerebral hemispheres separated by septum pellucidum.

Third Ventricle

Midline ventricle located in the diencephalon; communicates with lateral ventricles via interventricular foramina.

Fourth Ventricle

Ventricle between pons/medulla and cerebellum; continuous with central canal of spinal cord.

Cerebral Aqueduct

Narrow canal through the midbrain connecting third and fourth ventricles.

Choroid Plexus

Capillary-ependymal complex that produces cerebrospinal fluid (≈500 mL/day).

Cerebrospinal Fluid (CSF)

Clear fluid that supports, cushions, and transports nutrients/wastes within the CNS.

Blood Brain Barrier (BBB)

Tight-junction seal around CNS capillaries that restricts passage of most substances from blood to brain.

Blood–CSF Barrier

Tight junctions between ependymal cells of choroid plexus that regulate exchange between blood and CSF.

Cranial Meninges

Three connective-tissue layers (dura, arachnoid, pia) that protect and stabilize the brain.

Dura Mater

Tough outer meningeal layer; forms periosteal and meningeal sheets and dural folds.

Arachnoid Mater

Middle meningeal layer; encloses subarachnoid space filled with CSF.

Pia Mater

Delicate innermost meningeal layer adhered to brain surface by astrocytes.

Falx Cerebri

Dural fold that separates cerebral hemispheres and houses superior and inferior sagittal sinuses.

Tentorium Cerebelli

Dural fold separating cerebrum from cerebellum; contains transverse sinus.

Falx Cerebelli

Dural fold that partially separates cerebellar hemispheres.

Arachnoid Villi

Fingerlike projections in dural sinuses through which CSF is absorbed into venous blood.

Dural Venous Sinuses

Vein-filled channels within dura mater that drain blood from brain to internal jugular veins.

Gracile Nucleus

Medulla relay nucleus for fine touch from lower body to thalamus; decussates at pyramids.

Cuneate Nucleus

Medulla relay nucleus for fine touch from upper body to thalamus.

Inferior Olivary Complex

Medullary nuclei (olives) that relay motor information to cerebellum.

Reticular Formation

Network of gray and white matter throughout brainstem that regulates autonomic functions and alertness.

Cardiovascular Centers

Medullary nuclei controlling heart rate and blood vessel diameter.

Respiratory Rhythmicity Centers

Medullary nuclei that set basic breathing pace.

Apneustic Center

Pons nucleus that promotes inhalation by stimulating medullary respiratory centers.

Pneumotaxic Center

Pons nucleus that inhibits apneustic center, regulating breathing rate and depth.

Corpora Quadrigemina

Four midbrain tectal nuclei (superior & inferior colliculi) processing visual and auditory reflexes.

Superior Colliculi

Midbrain nuclei that mediate visual reflexes such as tracking moving objects.

Inferior Colliculi

Midbrain nuclei that mediate auditory reflexes such as startle response.

Red Nucleus

Midbrain tegmental nucleus rich in blood supply; involved in motor coordination.

Substantia Nigra

Dopamine-producing midbrain nucleus; degeneration leads to Parkinson’s disease.

Purkinje Cell

Large, branched cerebellar neuron receiving up to 200,000 synapses; key to cerebellar output.

Arbor Vitae

Tree-like pattern of white matter inside cerebellum containing cerebellar nuclei.

Ataxia

Motor disorder of cerebellar origin causing uncoordinated movements.

Pineal Gland

Endocrine gland in epithalamus that secretes melatonin and regulates circadian rhythms.

Limbic System

Interconnected structures that produce emotions, link cognition with autonomics, and aid memory.

Amygdaloid Body

Limbic nucleus linking emotions with memories and sensory inputs.

Fornix

White-matter tract connecting hippocampus to hypothalamus.

Basal Nuclei

Subcortical gray matter masses that regulate subconscious movements and muscle tone.

Caudate Nucleus

C-shaped basal nucleus with head and tail involved in motor processing.

Lentiform Nucleus

Basal nucleus composed of putamen and globus pallidus.

Putamen

Lateral portion of lentiform nucleus aiding movement regulation.

Globus Pallidus

Medial portion of lentiform nucleus influencing muscle tone.

Claustrum

Thin gray-matter layer lateral to putamen; function not fully understood.

Primary Motor Cortex

Precentral gyrus area that issues voluntary motor commands via pyramidal cells.

Primary Somatosensory Cortex

Postcentral gyrus area receiving touch, pressure, pain, and temperature information.

Premotor Cortex

Somatic motor association area that plans and coordinates learned movements.

Somatosensory Association Cortex

Interprets sensations coming from primary somatosensory cortex (e.g., texture recognition).

Visual Cortex

Occipital lobe area processing visual stimuli.

Auditory Cortex

Temporal lobe area processing hearing.

Olfactory Cortex

Temporal lobe (insula) area processing smell.

Gustatory Cortex

Insular/frontal lobe area processing taste.

Wernicke’s Area

Left-hemisphere region for language comprehension and interpretation.

Broca’s Area

Left frontal region controlling speech production and articulation.

Prefrontal Cortex

Anterior frontal lobe region responsible for abstract thought, judgment, and prediction.

Alpha Waves

8–13 Hz EEG pattern in relaxed, awake adults with eyes closed.

Beta Waves

14–30 Hz EEG pattern during active concentration or stress.

Theta Waves

4–7 Hz EEG pattern in children or frustrated adults; may signal pathology in adults.

Delta Waves

Cranial Nerves

Twelve pairs of nerves emerging from brain that carry sensory, motor, or mixed signals.

Olfactory Nerve (I)

Purely sensory cranial nerve conveying smell from nasal epithelium to olfactory bulbs.

Optic Nerve (II)

Sensory nerve carrying visual information from retina to diencephalon via optic chiasm.

Oculomotor Nerve (III)

Motor nerve controlling four extrinsic eye muscles and intrinsic eye muscles via ciliary ganglion.

Trochlear Nerve (IV)

Motor nerve innervating the superior oblique muscle of the eye.

Trigeminal Nerve (V)

Largest cranial nerve; provides facial sensation (V1, V2, V3) and motor control of mastication.

Abducens Nerve (VI)

Motor nerve innervating the lateral rectus muscle, abducting the eye.

Facial Nerve (VII)

Mixed nerve for taste (anterior 2⁄3 tongue), facial expression muscles, and salivary/lacrimal glands.

Vestibulocochlear Nerve (VIII)

Sensory nerve composed of vestibular (balance) and cochlear (hearing) branches.

Glossopharyngeal Nerve (IX)

Mixed nerve for taste (posterior 1⁄3 tongue), swallowing muscles, and parotid gland secretion.

Vagus Nerve (X)

Mixed nerve widely innervating thoracic and abdominal organs; major parasympathetic outflow.

Accessory Nerve (XI)

Motor nerve with cranial and spinal roots; controls palate, pharynx, larynx, SCM, and trapezius.

Hypoglossal Nerve (XII)

Motor nerve controlling intrinsic and extrinsic tongue muscles.

Tic Douloureux

Painful trigeminal neuralgia affecting maxillary and/or mandibular divisions of CN V.

Bell’s Palsy

Facial nerve inflammation causing unilateral facial paralysis and altered taste.

Seizure

Transient cerebral disorder with abnormal synchronized neuronal activity producing varied symptoms.