Which cranial nerve is numbered XI?

Which cranial nerve is numbered XI?

• A. Abducens nerve (VI)
• B. Accessory nerve (XI)
• C. Trochlear nerve (IV)
• D. Olfactory nerve (I)

Answer: (B)

Cranial nerves are numbered I through XII in the order they emerge from the brainstem. The eleventh cranial nerve is the Accessory nerve, a primarily motor nerve that Innervates the sternocleidomastoid and trapezius muscles, enabling head turning and shoulder shrugging. It has a spinal component that ascends to join its cranial part before exiting the skull. In the list given, the nerve that matches this number and name is the Accessory nerve. The others correspond to different nerves with different functions: the Abducens moves the eye laterally, the Trochlear also moves the eye (via the superior oblique), and the Olfactory carries smell.

Cranial nerves are numbered I through XII in the order they emerge from the brainstem. The eleventh cranial nerve is the Accessory nerve, a primarily motor nerve that Innervates the sternocleidomastoid and trapezius muscles, enabling head turning and shoulder shrugging. It has a spinal component that ascends to join its cranial part before exiting the skull. In the list given, the nerve that matches this number and name is the Accessory nerve. The others correspond to different nerves with different functions: the Abducens moves the eye laterally, the Trochlear also moves the eye (via the superior oblique), and the Olfactory carries smell.