The conus medullaris is at L1-2. Within the intervertebral foramen, attached to the periosteum surrounding it. Examine dorsal and ventral rootlets as they emerge from the cord. Rootlets coalesce as they enter the dural sleeve, lateral to their exit from the cord, thereby forming segmental roots. The roots are nerves which leave the gray matter through ventral or dorsal horns and unite to become the spinal nerve.
Ventral roots carry motor fibers, both somatic and visceral.
Dorsal roots carry sensory fibers. The dorsal root ganglion is located in the intervertebral foramen on the dorsal root. There is one ganglion per spinal nerve. Trace the roots to the point of union to form the spinal nerve. No, the spinal nerve roots are usually contained within a common sleeve of dura mater.