Anat&Phy 337 Unit 3 Terms

Unit 3 Terms

Cerebrum

The largest region of the brain, responsible for higher neurological functions such as memory, emotion, language, and conscious thought.

Cerebral Cortex

Thin outer layer of gray matter covering the cerebrum where conscious cognition and complex information processing occur.

Cerebral Hemispheres

The two anatomically similar right and left halves of the cerebrum.

Hemispheric Laterlization

Functional specialization and division of labor between the left and right cerebral hemispheres.

Sulci

Shallow grooves on the surface of the cerebral cortex separating ridges.

Gyri

Raised folds or ridges on the surface of the cerebral cortex.

Median longitudinal fissure

 Deep midline groove that separates the left and right cerebral hemispheres.

Central sulcus

Groove separating the frontal lobe anteriorly from the parietal lobe posteriorly.

Lateral sulcus (Sylvian fissure)

Deep groove separating the temporal lobe inferiorly from the frontal and parietal lobes.

Parieto-occipital sulcus

Groove separating the parietal lobe from the occipital lobe posteriorly.

Central White Matter

Myelinated axon pathways underlying the cerebral cortex that transmit signals between cortical regions and lower CNS centers.

Commisure

White matter tract that connects corresponding regions of the right and left cerebral hemispheres.

Corpus Callosum

Large primary commissural white matter pathway connecting the two cerebral hemispheres.

Anterior Commisure

Smaller commissural white matter bundle connecting the left and right cerebral hemispheres.

Association Fibers

Axon tracts connecting different cortical areas within the same cerebral hemisphere.

Projection Fibers

Axon tracts running vertically to connect the cerebral cortex with lower brain regions, brainstem, or spinal cord.

Brodmann’s areas

Map of the cerebral cortex divided into 52 numbered areas based on cytoarchitectural (histological) differences.

Motor areas

Cortical regions controlling voluntary motor movements.

Sensory areas

Cortical regions providing conscious awareness of incoming sensations.

Multimodal association areas

Cortical regions that integrate and interpret inputs from multiple sensory and motor areas.

Insula

Deep cortical lobe located beneath the lateral sulcus, containing the primary gustatory cortex for taste processing.

Occipital lobe

Posterior cerebral lobe dedicated to receiving and processing visual information.

Frontal lobe

Anterior cerebral lobe controlling voluntary motor activity, higher-order cognition, executive functions, and personality.

Prefrontal cortex

Anterior-most portion of the frontal lobe governing higher cognitive functions, decision-making, planning, and goal-directed behavior.

Dorsolateral prefrontal cortex

Subregion controlling executive functions, organization, planning, multitasking, and working memory.

Orbitofrontal cortex

Subregion involved in modulating emotions, behavioral inhibition, adaptive learning, and reward processing.

Anterior cingulate cortex

Subregion regulating motivational behavior, reward-based learning, error detection, outcome monitoring, and pain processing.

Precentral gyrus

Gyrus located immediately anterior to the central sulcus that contains the primary motor cortex.

Primary motor cortex

Functional area (BA 4) in the precentral gyrus initiating voluntary skeletal muscle contractions.

Motor homunculus

Topographical map representing the body's musculature along the primary motor cortex.

Supplementary & premotor areas

Cortical regions adjacent to the primary motor cortex responsible for planning and coordinating complex, learned, skilled movements.

Broca’s area

Motor speech area in the inferolateral frontal lobe (usually left hemisphere) controlling movements required for speech production.

Broca’s Aphasia

Condition where language comprehension remains intact, but verbal communication/speech production is severely impaired.

Parietal Lobe

Superoposterior lobe responsible for general somatosensation (touch, pressure, temperature), spatial orientation, and attention.

Postcentral gyrus

Gyrus posterior to the central sulcus that houses the primary somatosensory cortex.

Primary somatosensory cortex

Functional area in the postcentral gyrus receiving general sensory information from the body.

Somatosensory homunculus

Topographical representation of body sensory inputs across the postcentral gyrus.

Somatosensory association areas

Cortical areas adjacent to the primary somatosensory cortex that interpret and contextualize general sensory data.

Wernicke’s area

Functional region overlapping the left parietal and temporal lobes responsible for comprehending spoken and written language.

Wernicke’s aphasia

Condition marked by fluent but meaningless speech, along with impaired language comprehension and repetition.

Temporal lobe

Inferior cerebral lobe involved in hearing, smell, memory consolidation, and emotional processing.

Superior, middle, and inferior gyri

Parallel longitudinal ridges running along the lateral aspect of the temporal lobe.

Hippocampus

Medial temporal lobe structure essential for learning, memory storage, and forming long-term episodic memories.

Amygdala

Medial temporal lobe structure anterior to the hippocampus that links sensory experiences to emotional responses (especially fear).

Limbic System

Ring of structures (including hippocampus, amygdala, and cingulate gyrus) that process emotions, drive behaviors, and support memory formation.

Basal nuclei

Paired gray matter nuclei deep within the cerebral white matter that control posture, adjust movement rhythm, and coordinate voluntary movements.

Caudate Nucleus

Long C-shaped nucleus following the curve of the lateral ventricle.

Putamen

Large, laterally situated basal nucleus that works with the caudate to control motor output.

Globus Pallidus

Layered nucleus lying medial to the putamen that regulates muscle tone.

Rostral

Towards the anterior/front portion of the brain (towards the nose).

Caudal

Towards the posterior/tail end of the brainstem and spinal cord.

Ventral

Towards the belly or inferior side of the brain/brainstem.

Dorsal

Towards the back or superior side of the brain/brainstem.

Telencephalon

The embryonic region that gives rise to the cerebrum.

Dienchephalon

Deep brain region comprising the thalamus and hypothalamus surrounding the third ventricle.

Mesencephalon

The midbrain portion of the brainstem.

Metencephalon

The embryonic brain region that develops into the pons and cerebellum.

Myelencephalon

The embryonic brain region that develops into the medulla oblongata.

Thalamus

Paired collection of gray matter nuclei serving as the primary relay station for filtering and relaying sensory information to the cerebral cortex.

Hypothalamus

Inferior region of the diencephalon serving as the master controller of the autonomic nervous system and endocrine system.

Pituitary gland

Endocrine gland connected to the inferior aspect of the hypothalamus.

Anterior pituitary/adenohypophysis

Glandular portion of the pituitary controlled by hypothalamic releasing and inhibiting hormones via the hypophyseal portal system.

Posterior pituitary/neurohypophysis

Neural extension of the hypothalamus that stores and releases oxytocin and ADH synthesized in the hypothalamus.

Infundibulum

Stalk of tissue connecting the hypothalamus to the pituitary gland.

Cerebellum

Structure inferior to the occipital lobe that fine-tunes and coordinates voluntary movements, posture, muscle tone, and motor learning.

Cerebellar peduncles

White matter tracts connecting the cerebellum to the brainstem.

Superior Peduncle

Connects the cerebellum to the midbrain.

Middle Peduncle

Connects the cerebellum to the pons.

Inferior Peduncle

Connects the cerebellum to the medulla oblongata.

Folia

Slender, leaf-like parallel cortical folds on the surface of the cerebellum.

Anterior Lobe & Posterior Lobe

Primary anatomical lobes of the cerebellum separated by the primary fissure.

Primary fissure

Deep transverse groove separating the anterior and posterior lobes of the cerebellum.

Vermis

Narrow midline tissue connecting the left and right cerebellar hemispheres.

Flocculonodular lobes

Small anterior-inferior cerebellar lobes involved in regulating balance and equilibrium.

Brainstem

Region connecting the forebrain to the spinal cord, comprising the midbrain, pons, and medulla oblongata.

Reticular formation

Diffuse network of gray matter throughout the brainstem regulating consciousness, arousal, and wakefulness.

Midbrain

Superior region of the brainstem surrounding the cerebral aqueduct.

Tectum

Posterior roof of the midbrain holding sensory reflex nuclei.

Corpora quadrigemina

 Four prominent bumps (two pairs of colliculi) on the tectum.

Superior colliculi

Superior pair controlling visual reflexes and tracking.

Inferior colliculi

Inferior pair controlling auditory reflexes.

Substantia nigra

Dopamine-secreting midbrain nucleus connected to the basal ganglia for movement modulation.

Red nucleus

Midbrain nucleus involved in involuntary motor control and maintaining muscle tone.

Cerebral peduncles

Prominent motor axon tracts on the ventral aspect of the midbrain.

Pons

Prominent anterior bulge of the brainstem situated between the midbrain and medulla oblongata.

Pontine respiratory center

Autonomic nuclei in the pons that modify the activity of the medullary respiratory center

Medulla Oblongata

Inferior region of the brainstem continuous with the spinal cord.

Medullary pyramids

Anterior longitudinal ridges on the medulla containing descending motor corticospinal tracts.

Medullary pyramidal dissection

Crossover point of corticospinal tract fibers at the inferior end of the medulla.

Medullary Cardiovascular center

Autonomic nuclei in the medulla regulating heart rate, force of contraction, and blood vessel diameter.

Medullary Respiratory Center

 Autonomic nuclei setting the basic rhythm of breathing.

Vertebral arteries

Paired arteries arising from the subclavian arteries that ascend through the transverse foramina of the cervical vertebrae, enter the cranium via the foramen magnum, and unite to form the basilar artery supplying the brainstem, cerebellum, and posterior cerebral regions.

Internal carotid arteries

Major paired arterial trunks branching from the common carotid arteries that enter the cranium through the carotid canal of the temporal bone to supply the anterior and middle portions of the brain.

Anterior cerebral arteries

Arterial branches originating from the internal carotid arteries that perfuse the anterior, medial, and superior aspects of the frontal lobes.

Middle cerebral arteries

Major branches of the internal carotid arteries delivering blood to the lateral surface of the cerebral hemispheres, including the posterior frontal lobe and most of the temporal and parietal lobes.

Posterior cerebral arteries

Terminal branches of the basilar artery that supply blood to the occipital lobes and the inferior surface of the posterior temporal lobes.

Circle of Willis (Arterial Circle)

An arterial anastomosis at the base of the brain formed by the internal carotid and vertebral arterial systems, providing collateral circulation to maintain perfusion if flow through one vessel is obstructed.

Anterior communicating artery

A short anastomotic arterial bridge connecting the left and right anterior cerebral arteries to complete the anterior segment of the Circle of Willis.

Posterior communicating artery

Paired arteries on each side connecting the internal carotid artery to the posterior cerebral artery, forming the posterolateral segments of the Circle of Willis.

Internal jugular vein

The primary deep venous channel exiting the cranium via the jugular foramen, receiving blood from dural venous sinuses and facial veins to transport deoxygenated blood back to the heart.