C5 spinal nerve

Nervus spinalis C5

NervousNervesNeckLeft and right

View left in 3D View right in 3D

What it is
The C5 spinal nerve leaves the spinal canal between C4 and C5. 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 skin over the deltoid (the "regimental badge" area).
Size
About 4-5 mm thick; the mixed nerve is only ~1 cm long before it divides
Clinical note
Test: shoulder abduction and the biceps reflex. Traction on C5-C6 at birth (Erb palsy) leaves the arm hanging in the "waiter's tip" posture.

Nearby nervous structures C2 spinal nerve, C3 spinal nerve, C4 spinal nerve, C6 dorsal root ganglion, C6 spinal nerve, C7 spinal nerve, C8 spinal nerve