Anatomy of the Nervous System: Systems, Structures, and Cells

A set of vocabulary-style flashcards covering key divisions, structures, cells, and techniques from the chapter on the anatomy of the nervous system.

CNS

The part of the nervous system consisting of the brain and spinal cord.

PNS

All neural structures outside the CNS.

Somatic nervous system

Part of the PNS that controls voluntary movements and conveys sensory information to the CNS.

Autonomic nervous system

Part of the PNS regulating involuntary functions; includes sympathetic and parasympathetic divisions.

Afferent

Nerve fibers carrying sensory information toward the CNS.

Efferent

Nerve fibers carrying motor commands away from the CNS.

Sympathetic

Division of the autonomic nervous system involved in arousal and energy mobilization (fight-or-flight).

Parasympathetic

Division of the autonomic nervous system promoting rest-and-digest activities.

Dura mater

Tough outer layer of the meninges.

Arachnoid

Middle meningeal layer with a web-like structure.

Pia mater

Innermost meningeal layer closely following the brain surface.

Cerebrospinal fluid (CSF)

Clear fluid produced by the choroid plexus that cushions the brain and spinal cord, circulating in ventricles and subarachnoid space.

Choroid plexus

Vascular tissue in ventricles that manufactures CSF.

Ventricles

Brain cavities that contain CSF (lateral, third, fourth ventricles; central canal).

Lateral ventricles

Paired ventricles in each hemisphere that produce CSF.

Third ventricle

Midline ventricle between the thalami.

Fourth ventricle

Ventricular cavity between brainstem and cerebellum.

Central canal

CSF-filled canal through the length of the spinal cord.

Blood-brain barrier

Tightly packed endothelial junctions that protect the brain and regulate entry of substances; requires active transport for some molecules (e.g., glucose).

Oligodendrocyte

Glial cell that myelinates CNS axons.

Schwann cell

Glial cell that myelinates PNS axons.

Microglia

Immune-supporting glia in the CNS; involved in debris clearance and synaptic remodeling.

Astroglia

Astrocytes; glial cells that support neurons, regulate blood flow, and help maintain the extracellular environment and blood–brain barrier.

Golgi stain

Staining method that reveals individual neurons in great detail.

Nissl stain

Staining method that highlights neuronal cell bodies and helps outline brain structure.

Electron microscopy

High-resolution imaging technique that reveals ultrastructural details of neurons.

Anterograde tracing

Neuroanatomical tracing from soma to terminals to map projections.

Retrograde tracing

Neuroanatomical tracing from terminals back to the soma to map inputs.

Dorsal root

Sensory (afferent) root entering the spinal cord.

Ventral root

Motor (efferent) root exiting the spinal cord.

Dorsal horn

Dorsal region of spinal cord gray matter containing sensory neurons.

Ventral horn

Ventral region of spinal cord gray matter containing motor neurons.

Spinal nerves

31 pairs of mixed nerves connecting the spinal cord to the body.

Thalamus

Sensory relay center of the brain; reciprocal connections with the cortex.

Hypothalamus

Brain region involved in endocrine function and motivated behaviors; contains mammillary bodies and is near the optic chiasm.

Optic chiasm

Point where optic nerve fibers cross; located near the hypothalamus.

Corpus callosum

Large bundle of fibers connecting the two cerebral hemispheres.

Neocortex

Six-layered outer portion of the cerebral cortex involved in higher-order processing.

Basal ganglia

Group of subcortical nuclei regulating movement; includes caudate, putamen, and globus pallidus.

Caudate

A component of the basal ganglia.

Putamen

A component of the basal ganglia.

Globus pallidus

A basal ganglia structure involved in movement regulation.

Cerebellum

Brain region involved in coordination of movement and some cognitive functions.

Medulla

Part of the myelencephalon; contains ascending/descending tracts and vital autonomic centers.

Pons

Part of the metencephalon; contains the reticular formation and relays between brain regions.

Mesencephalon

Midbrain.

Myelencephalon

Hindbrain region that includes the medulla.

Metencephalon

Hindbrain region that includes the cerebellum and pons.

Diencephalon

Forebrain region containing the thalamus and hypothalamus.

Telencephalon

Forebrain region including the cerebral cortex and basal ganglia; contains the lobes.

Reticular formation

Core network of nuclei in the brainstem involved in arousal; also called the reticular activating system.