Fibre (medical)

A fibre or fiber is a myelinated nerve fiber in somatic nerves, measuring 1 to 22 μm in diameter, conducting nerve impulses at a rate of 6 to 120 m/s. They have the highest conduction velocity out of A, B and C fibers because they are the most heavily myelinated of the three groups and because they generally have a larger diameter, which reduces resistance to flow.