Dorsal Nerve Roots

Synonyms

Sensory nerve roots

Definition

Nerve fibers entering the spinal cord that carry somatosensory data such as pain, temperature, pressure, touch, state of muscular contraction, and related information. These fibers originate from various types of nerve endings in the skin, muscles and joints of the trunk, extremities, and back and top of the head and travel to the spinal cord in the nerve bundles collectively referred to as the spinal or peripheral nerves. The latter consist not only of sensory fibers travelling toward the cord, but also motor fibers exiting the cord and heading toward muscles. As these peripheral nerves reach the vertebral column, the afferent or sensory fibers split off from the exiting efferent or motor fibers and enter the cord dorsally (posteriorly) at the dorsolateral sulcus (see Fig. 1). This short segment between where the peripheral nerve divides into its sensory and motor components and these afferent fibers enter the cord is known as the dorsal nerve...