The diameter of Type C fibers is
Unmyelinated fibers carrying pain, itch, temperature, and crude touch sensations (0.5 to 2 micrometers in diameter; they are type C fibers in the generalclassification).Ref: Guyton; 13th edition; Chapter 47 Sensory Receptors, Neuronal Circuits for Processing Information
13-20mm
4-13mm
3-6mm
0.5-2mm
General physiology