C6 spinal nerve

Nervus spinalis C6

NervousNervesNeckLeft and right

View left in 3D View right in 3D

What it is
The C6 spinal nerve leaves the spinal canal between C5 and C6. 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 lateral forearm, thumb and index finger.
Size
About 4-5 mm thick; the mixed nerve is only ~1 cm long before it divides
Clinical note
Test: elbow flexion, wrist extension and the brachioradialis reflex; a C5/6 disc prolapse sends pain and tingling into the thumb.