C8 spinal nerve
Nervus spinalis C8
NervousNervesNeckLeft and right
View left in 3D View right in 3D
- What it is
- The C8 spinal nerve leaves the spinal canal between C7 and T1. Its sensory (dorsal) and motor (ventral) roots meet just beyond the dorsal root ganglion; the short mixed nerve then splits into a small dorsal ramus for the back muscles and skin and a larger ventral ramus, which joins the brachial plexus.
- Function
- Carries motor fibres to the muscles of its segment (myotome) and sensation back from its strip of skin (dermatome): the little finger and the medial forearm.
- Size
- About 4-5 mm thick; the mixed nerve is only ~1 cm long before it divides
- Clinical note
- There are eight cervical nerves but only seven cervical vertebrae, so C8 exits below C7. Test: finger flexion and grip.