Which nerve is NOT derived from a cranial nerve?

Which nerve is NOT derived from a cranial nerve?

• A. Great auricular
• B. Infraorbital
• C. Supratrochlear
• D. Supraorbital

Answer: (A)

The main concept is that some nerves originate from the cranial nerves (like the trigeminal nerve, a cranial nerve), while others come from the cervical plexus. The Great auricular nerve comes from the cervical plexus (ventral rami of C2-C3), not from a cranial nerve. In contrast, the infraorbital nerve is a branch of the maxillary division of the trigeminal nerve (cranial nerve V), while the supratrochlear and supraorbital nerves are branches of the frontal nerve from the ophthalmic division of V (also cranial nerve V). So the nerve not derived from a cranial nerve is the Great auricular, since it arises from the cervical nerves rather than the brainstem-origin cranial nerves.

The main concept is that some nerves originate from the cranial nerves (like the trigeminal nerve, a cranial nerve), while others come from the cervical plexus. The Great auricular nerve comes from the cervical plexus (ventral rami of C2-C3), not from a cranial nerve. In contrast, the infraorbital nerve is a branch of the maxillary division of the trigeminal nerve (cranial nerve V), while the supratrochlear and supraorbital nerves are branches of the frontal nerve from the ophthalmic division of V (also cranial nerve V). So the nerve not derived from a cranial nerve is the Great auricular, since it arises from the cervical nerves rather than the brainstem-origin cranial nerves.