Spinal Cord - Microscopic / Cross-Section Anatomy

White Matter

Outer region of a spinal cord cross section. Has 3 columns: Dorsal Funiculus, Lateral Funiculus, and Ventral Funiculus. Lighter outer area surrounding the butterfly-shaped gray matter.

Dorsal Funiculus

White matter on the posterior side of the spinal cord. White matter between the two dorsal horns. Posterior = Dorsal

Ventral Funiculus

White matter on the anterior side. White matter anterior to the ventral horns. Anterior = Ventral

Lateral Funiculus

White matter on the sides of the spinal cord. White matter lateral to the gray horns. Side = Lateral

Dorsal Median Sulcus

Shallow groove along the posterior/dorsal midline of the spinal cord. Small/shallow indentation on the dorsal side.

(Top Middle)

Ventral Median Fissure

Deep groove along the anterior/ventral midline. The large, deep indentation.

(Bottom Middle)

Dorsal Horn

Posterior/dorsal projection of gray matter. The thin, pointed upper wings of the butterfly-shaped gray matter.

Ventral Horn

Anterior/ventral projection of gray matter. Usually the large, rounder/broader horns. Toward deep ventral fissure.

Lateral Horn

Lateral projection of gray matter. Small gray-matter projection sticking outward between the dorsal and ventral horns.

Gray Commissure

Gray matter connecting the left and right sides of the spinal cord. Center of the butterfly-shaped gray matter. Gray bridge surrounding the central canal.

Central Canal

Small space in the center of the spinal cord. Within the gray commisure. Tiny hole/dot in the middle of the gray matter.

Dorsal Root

Enters the spinal cord on the dorsal/posterior side. Root associated with the dorsal root ganglion.

Ventral Root

Connected to the ventral/anterior side of the spinal cord. Root on the ventral side that does NOT have a ganglion.

Dorsal Root Ganglion

Plural = Ganglia. Enlargement associated with the dorsal root. Obvious bulge/swelling along the dorsal root.

Multipolar Neuron

Cell body with many processes extending from it/

Unipolar Neuron

Rounded cell body with a single main process.

Glial Cell/ Neuroglia

Typically appears much smaller than a neuron, often seen as small dark nuclei around neurons.

Gray Matter vs. White Matter

• Gray matter: Primarily neuron cell bodies, dendrites, synapses, and unmyelinated axons.

• White matter: Primarily bundles of myelinated axons.

• Spinal cord: Gray matter is internal; white matter is external.

• Cerebrum: Gray matter forms the outer cortex; white matter is deeper.