ANAT 20006: Nervous System 1 Practice Flashcards

A collection of vocabulary terms and definitions regarding the anatomical orientation, organization, and components of the vertebrate central and peripheral nervous systems as described in the ANAT 20006 lecture notes.

Neuraxis

The axis of the nervous system, which is essentially horizontal in quadrupeds but vertical in humans and rotated anteriorly at the rostral end.

Central nervous system (CNS)

The division of the vertebrate nervous system that comprises the brain and spinal cord.

Peripheral nervous system (PNS)

The nerves connecting the central nervous system to the body (periphery), including neuronal clusters known as ganglia.

Astrocyte

A type of glial cell found within the central nervous system alongside neurons and capillaries.

Oligodendrocyte

A glial cell in the CNS that provides insulation to nerve axons by forming the myelin sheath from its lipid bilayer cell membrane.

Diencephalon

A major part of the central nervous system composed of the hypothalamus, thalamus, and pineal gland (part of the epithalamus).

Brainstem

A division of the CNS located between the diencephalon and spinal cord, comprising the midbrain (mesencephalon), pons, and medulla oblongata.

Gyrus

A prominent ridge or fold on the surface of the cerebral cortex.

Sulcus

A groove or furrow on the surface of the brain, such as the central sulcus which separates the frontal and parietal lobes.

Fissure

A deep groove in the brain, such as the longitudinal fissure that separates the left and right cerebral hemispheres.

Meninges

The three membranes that wrap the Central Nervous System: the dura mater, arachnoid mater, and pia mater.

Falx cerebri

A dural fold located within the longitudinal fissure between the cerebral hemispheres.

Tentorium cerebelli

A dural fold that separates the cerebrum from the cerebellum.

Transtentorial herniation

A common CNS herniation characterized by oculomotor (CN III) paresis, including an ipsilateral dilated pupil and abnormal extraocular movements (EOM's).

Tonsillar herniation

A type of brain herniation that can lead to obtundation.

Choroid plexus

Specialized vascular tissue within the ventricles responsible for the production of cerebro-spinal fluid (CSF).

Arachnoid villi

Also known as granulations, these structures allow CSF to return to the venous circulation, specifically into the superior sagittal sinus.

Hydrocephalus

A condition caused when CSF does not return to circulation, often treated with a drainage tube inserted into the lateral ventricle and the peritoneal cavity.

Primary somatomotor cortex

The center for somatomotor output located on the precentral gyrus of the frontal lobe.

Calcarine sulcus

The sulcus surrounded by the primary visual cortex.

Schwann cells

Glial cells in the peripheral nervous system (PNS) that provide insulation to nerve axons.

White matter

Axonal bundles in the brain and spinal cord that appear white due to the myelin sheath insulation.

Conus medullaris

The tapered end of the spinal cord, which in adults is typically located at the level of the $L1-L2$ vertebrae.

Cauda equina

A collection of dorsal and ventral nerve roots (including the root of the first sacral nerve) that extends past the end of the spinal cord.

Thecal sac

The structure surrounding the spinal cord, containing CSF, which ends at the level of the $S2$ vertebra.

Lumbar puncture

A procedure where a needle is inserted between vertebrae (e.g., $L3$ and $L4$) to collect cerebrospinal fluid from the thecal sac.

Pyramidal tracts

Motor and descending (efferent) pathways in the spinal cord, including the lateral and anterior corticospinal tracts.

Dorsal Column Medial Lemniscus System

A sensory and ascending (afferent) pathway composed of the gracile fasciculus and cuneate fasciculus.