The dorsal root contains afferent (sensory) fibers that transmit information to the spinal cord from the sensory receptors. The ventral root contains efferent (motor) fibers that carry messages from the spinal cord to the effectors. Cell bodies of the efferent fibers reside in the spinal cord gray matter. These roots become nerves that innervate (transmit nerve impulses to) muscles and organs throughout the body. Twelve pairs of cranial nerves transmit from special sensory receptors information on the senses of balance, smell, sight, taste, and hearing.