A nerve fiber is the process of a nerve cell ensheathed by glial cells, such as the axon of a nerve cell together with its myelin sheath. In the peripheral nervous system, several nerve fibers are usually grouped into nerves by additional connective tissue sheaths.
Classification by conduction velocity according to Erlanger and Gasser
| Fiber class | Conduction velocity | Diameter |
|---|---|---|
| Aα | 70–120 m/s | 10–20 µm |
| Aβ | 30–70 m/s | 7–15 µm |
| Aγ | 15–30 m/s | 4–8 µm |
| Aδ | 12–30 m/s | 2–5 µm |
| B | 3–15 m/s | 1–3 µm |
| C | 0,5–2 m/s | 0,1–1,5 µm |