Classification of Peripheral Nerve Fibers

Myelinated Fiber Diameter (mm) Conduction Velocity (m/s) Function Sensitivity to Local Anesthetic (Subarachnoid, Procaine, %) A- Yes 12-20 70-120 Innervation of skeletal muscles 1 Proprioception A- Yes 5-12 30-70 Touch 1 Pressure A- Yes 3-6 15-30 Skeletal muscle tone 1 A-δ Yes 2-5 12-30 Fast pain 0.5 Touch Temperature B Yes 3 3-15 Preganglionic autonomic fibers 0.25 C No 0.4-1.2 0.5-2.0 Slow pain 0.5 Touch Temperature Postganglionic sympathetic fibers