Template:Peripheral Nerve Fibres
From WikiMSK
- Characteristics of peripheral nerve fibres
Nerve Fibre | Myelin | Diameter (µm) | Conduction velocity (m/s) | General Function |
---|---|---|---|---|
Aα (I) | Yes | 13-20 | 80-120 | Proprioception: muscle spindle primary endings (Ia), golgi tendon organs (Ib), and alpha motor neurons |
Aβ (II) | Yes | 6-12 | 35-75 | Discriminative sensitivity to mechanical stimuli (touch, vibration), proprioception, pain modulation (block nociceptive information, allodynia in sensitisation) |
Aγ | Yes | 4-8 | 15-40 | Touch, pressure, and gamma motor neurons. |
Aδ (III) | Thin | 1-5 | 5-30 | "rapid" pain, crude touch, pressure, temperature. AMH type I for rapid mechanical pain (high heat threshold >53C), AMH type II for rapid heat pain (lower heat threshold 43-47C). |
B | No | 1-3 | 3-14 | preganglionic autonomic |
C (IV) | No | 0.2-1.5 | 0.5-2.0 | "second" pain, mechanical, chemical, thermal, pruritis, and postganglionic autonomic. polymodal |