Anterior Roots of Sacral Nerves (Left)

Description

The anterior (ventral or motor) roots of sacral nerves arise bilaterally from the anterior aspect of the spinal cord as a series of smaller rootlets that merge to form the anterior root.

The anterior roots contain information traveling away from the spinal cord. This consists of all lower motor neuronal axons from these spinal levels. In addition, axons from preganglionic parasympathetic neurons exit the spinal cord via the anterior roots of the second, third, and fourth sacral nerves.

Anterior sacral roots originate near the conus medularis, roughly at the first lumbar vertebral level. They run inferiorly as roots of the cauda equine, towards the sacral foramina. Within the vertebral canal, they merge with the corresponding posterior (dorsal) root, adjacent to a sacral foramen, to form a sacral nerve.