Spinal Cord

Front 1

dorsal roots

Back 1

The centrally directed axonsof the sensory neurons. Terminate in the dorsalhorn.

Front 2

the soma of sensoryneurons are clustered in the

Back 2

dorsal root ganglia.

Front 3

Motor neurons have theirsoma in the

Back 3

ventral horn

Front 4

and their axons in the

Back 4

ventral roots.

Front 5

spinal nerve

Back 5

contains the peripherally directed axons of sensory and motor neurons and is formedby the merger of dorsal and ventral roots just as they exit the spinal column through theintervertebral foramen.

Front 6

The thinner dorsal ramus

Back 6

innervates structures along the back or dorsal surface

Front 7

the thickerventral ramus

Back 7

innervates structures on the front or ventral surface.

Front 8

intermediate (lateral)horn

Back 8

contains the cell bodies of preganglionic motor neurons of the autonomic nervoussystem. Their axons exit the ventral roots, travel through spinal nerves, and synapse onpostganglionic motor neurons that innervate the smooth muscles of internal organs.

Front 9

The spinal cord itself ends

Back 9

between the L1-L2 vertebrae because ofthe more rapid growth of the vertebral column vs. the spinal cordduring development.

Front 10

The dorsal and ventral roots thatexit the spinal column at lower levels stretch to form the

Back 10

caudaequina, surrounded by the cerebrospinal fluid-filled lumbarcistern (where spinal taps are drawn from).

Front 11

Rexed's laminae

Back 11

Neurons with similar size, shape, and function are clustered into longitudinal columnsof gray matter that appear like layers in the coronal plane. Equivalent of spinal cord nuclei.

Front 12

Layers I-VI

Back 12

lie in the dorsal horn. Neurons here process and relay sensory information.

Front 13

Layers VIII and IX

Back 13

of the ventral horn contain somatic motor neurons.

Front 14

Layer VII

Back 14

represents the intermediate (lateral) horn and contains preganglionic autonomic motor neurons.

Front 15

Layer X

Back 15

surrounds the central canal.

Front 16

funiculi

Back 16

Thesewhite matter bundles run the length of thespinal cord and are called columns (contain tracts). The largest are subdivided intofasciculi.