Primary afferent nociceptor Primary afferent axon bifurcates to send one process into the spinal cord and the other to innervate bodily tissue Primary afferents are classified by their diameter degree of myelination, and conduction velocity A-beta A-delta C fiberPrimary afferent nociceptor •Primary afferent axon bifurcates to send one process into the spinal cord and the other to innervate bodily tissue •Primary afferents are classified by their diameter, degree of myelination, and conduction velocity A-beta A-delta C fiber