The spinal cord can be seen within a transected lumbar vertebra.
A spinal cord segment is a region of spinal cord that gives rise to a pair of spinal nerves. Bilaterally, spinal nerves are formed by the union of dorsal and ventral spinal roots. Both the spinal cord and the spinal roots are enveloped by meninges, within the vertebral canal.
Spinal nerves are short. Each is found within an intervertebral foramen and each gives rise to a dorsal branch, a ventral branch, a ramus communicans, and a meningeal branch.
Meninges consist of pia mater (attached to nervous tissue), arachnoid (surrounding a subarachnoid space filled with cerebrospinal fluid), and dura mater (surrounded in turn by an epidural space. By running from pia mater to dura mater, denticulate ligament processes suspend the spinal cord within the subarachnoid space.
