Spinal nerves divide in the vertebral canal into two branches: the dorsal root and the ventral root. The dorsal root, which is the posterior branch, contains the axons of sensory neurons that bring information to the spinal cord. The ventral root, which is the anterior branch, contains the axons of motor neurons that carry commands to muscles or glands. Therefore, each spinal nerve is considered a mixed nerve with both sensory and motor neurons.