Dorsal ramus

Shortly after a spinal nerve exits the intervertebral foramen, it branches into the dorsal ramus, ventral ramus, and rami communicantes. Each of these latter three structures carries both sensory and motor information. Because each spinal nerve carries both sensory and motor information, spinal nerves are referred to as “mixed nerves.” Dorsal rami carry visceral motor, somatic motor, and sensory information to and from the skin and deep muscles of the back.

Dorsal rami remain distinct from each other, and each innervates a narrow strip of skin and muscle along the back, more or less at the level from which the ramus leaves the spinal nerve.