Neuroanatomy Glossary

Nerve fibers or pathways that carry sensory information toward the central nervous system (from periphery to brain/spinal cord).

A group of subcortical nuclei (caudate, putamen, globus pallidus, subthalamic nucleus, substantia nigra) involved in modulating voluntary movement, procedural learning, and reward.

A selective barrier formed by tight junctions of brain capillary endothelial cells that restricts passage of substances from the blood into the brain parenchyma.

The portion of the brain comprising the midbrain, pons, and medulla oblongata, connecting the cerebrum to the spinal cord and containing cranial nerve nuclei and vital centers.

A system of numbered cortical regions defined by cytoarchitectural differences, used to map functional areas of the cerebral cortex (e.g., area 4 = primary motor cortex, area 17 = primary visual cortex).

A structure in the posterior fossa responsible for coordination of voluntary movement, balance, equilibrium, and motor learning.

The outer layer of gray matter of the cerebrum, organized into six layers, responsible for higher cognitive functions including perception, motor control, language, and thought.

A clear, colorless fluid produced by the choroid plexus that fills the ventricles and subarachnoid space, providing mechanical protection, buoyancy, and waste removal for the brain and spinal cord.

An arterial anastomotic ring at the base of the brain connecting the anterior and posterior cerebral circulations, providing collateral blood flow.

The largest white matter commissure connecting the two cerebral hemispheres, allowing interhemispheric communication.

Twelve pairs of nerves that arise directly from the brain or brainstem, providing motor, sensory, and autonomic innervation primarily to the head and neck.

The crossing of nerve fibers from one side of the central nervous system to the other, as seen in the pyramidal decussation of the corticospinal tract in the medulla.

The part of the brain between the cerebral hemispheres and the midbrain, comprising the thalamus, hypothalamus, epithalamus, and subthalamus.

Nerve fibers or pathways that carry motor commands away from the central nervous system toward muscles and glands.

Neural tissue composed primarily of neuronal cell bodies, dendrites, unmyelinated axons, and synapses. Found in the cerebral cortex, deep nuclei, and central spinal cord.

A ridge on the surface of the cerebral cortex, bounded by sulci. Named gyri serve as anatomical landmarks (e.g., precentral gyrus, superior temporal gyrus).

A curved structure in the medial temporal lobe essential for the formation and consolidation of new declarative memories and spatial navigation.

A small diencephalic region below the thalamus that regulates homeostatic functions including temperature, hunger, thirst, circadian rhythm, and endocrine output via the pituitary gland.

A V-shaped white matter structure containing major ascending and descending fiber tracts between the cerebral cortex and the brainstem/spinal cord.

The three protective membranes (dura mater, arachnoid mater, pia mater) that surround and protect the brain and spinal cord.

A lipid-rich insulating sheath surrounding axons, formed by oligodendrocytes in the CNS and Schwann cells in the PNS, that increases the speed of action potential conduction.

The fundamental signaling cell of the nervous system, consisting of a cell body (soma), dendrites (receiving inputs), and an axon (transmitting output to other cells).

A groove or furrow on the surface of the cerebral cortex. Major sulci such as the central sulcus and lateral sulcus serve as landmarks separating brain lobes.

The junction between two neurons or between a neuron and an effector cell, where neurotransmitter release allows signal transmission across the synaptic cleft.

A large ovoid mass of nuclei in the diencephalon serving as the main relay and integration center for sensory information (except olfaction) traveling to the cerebral cortex.