Greater auricular nerve

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The greater auricular nerve is a cutaneous branch of the cervical plexus that innervates the skin of the auricle as well as skin over the parotid gland and mastoid process. The greater auricular nerve also supplies branches that innervate the deep layer of the parotid fascia.

Gross anatomy

Origin

The greater auricular nerve arises from the ventral rami of C2 and C3 spinal nerves , although it receives considerably more fibers from C2.

Course

The greater auricular nerve emerges along the posterior aspect of the sternocleidomastoid muscle at the punctum nervosum (Erb point) and ascends vertically across the oblique sternocleidomastoid muscle. When the greater auricular nerve approaches the inferior pole of the parotid gland it divides into anterior and posterior terminal branches.

Branches and supply
  • the anterior (or facial) branch supplies the skin of the face over the parotid gland and communicates with the facial nerve
  • the posterior (or mastoid) branch supplies the skin over the mastoid process and on the posterior surface of the auricle
    • a small lateral branch of the posterior branch pierces the auricle to supply the lobule and concha
    • the posterior branch of the greater auricular nerve communicates with the lesser occipital nerve, auricular branch of the facial nerve and posterior auricular branch of the facial nerve 
Relations

The anterior branch of the greater auricular nerve passes though the substance of the parotid gland. The posterior branch passes deep to the parotid gland to supply the deep layer of the parotid fascia.

Along with the other cutaneous branches of the cervical plexus the lesser occipital nerve passes posterior to the sternocleidomastoid muscle at the punctum nervosum roughly midway between the origin and insertion of the muscle.

Variant anatomy

A rare communication between the anterior branch of the greater auricular nerve and the marginal branch of the facial nerve has been reported in cadaveric studies. Terminal branches of the anterior division have been shown to have a highly variable branching pattern in relation to the parotid gland.

Related pathology

The greater auricular nerve may contribute to atypical headache and migraine in cases of great auricular neuralgia.