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.