Which nerve provides the external ear innervation via a CN VII branch?

Which nerve provides the external ear innervation via a CN VII branch?

• A. Posterior auricular cutaneous branches
• B. Great auricular nerve
• C. Lesser auricular nerve
• D. Auriculotemporal nerve

Answer: (A)

The key idea is that the facial nerve (cranial nerve VII) has branches that supply skin around the ear. The posterior auricular nerve, a branch of CN VII, travels behind the ear and gives cutaneous branches to the skin of the external ear in the posterior region. That makes these posterior auricular cutaneous branches the CN VII pathway for external ear innervation in that area. The other nerves come from different origins: the great auricular nerve is from the cervical plexus and covers the lower ear regions; the auriculotemporal nerve comes from the trigeminal nerve (V3) and supplies the anterior/superior ear; the lesser auricular nerve is not a CN VII posterior branch.

The key idea is that the facial nerve (cranial nerve VII) has branches that supply skin around the ear. The posterior auricular nerve, a branch of CN VII, travels behind the ear and gives cutaneous branches to the skin of the external ear in the posterior region. That makes these posterior auricular cutaneous branches the CN VII pathway for external ear innervation in that area.

The other nerves come from different origins: the great auricular nerve is from the cervical plexus and covers the lower ear regions; the auriculotemporal nerve comes from the trigeminal nerve (V3) and supplies the anterior/superior ear; the lesser auricular nerve is not a CN VII posterior branch.