C1 spinal nerve

Nervus spinalis C1

NervousNervesHeadLeft and right

View left in 3D View right in 3D

What it is
The C1 spinal nerve leaves the spinal canal between the occipital bone and the atlas. 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 cervical plexus.
Function
Carries motor fibres to the muscles of its segment (myotome) and sensation back from its strip of skin (dermatome): the suboccipital muscles (it usually has no skin territory).
Size
About 2-3 mm thick; the mixed nerve is only ~1 cm long before it divides
Clinical note
C1 is almost purely motor; some of its fibres travel with the hypoglossal nerve to reach the infrahyoid strap muscles via the ansa cervicalis.

Nearby nervous structures Accessory nerve root (CN XI), Facial nerve root (CN VII), Fourth ventricle, Glossopharyngeal nerve root (CN IX), Hypoglossal nerve root (CN XII), Medulla oblongata, Trigeminal nerve (CN V), root, Vagus nerve root (CN X), Vestibulocochlear nerve (CN VIII), Vestibulocochlear nerve root (CN VIII)