Final answer:
The trochlear nerve, also known as cranial nerve IV, passes through the superior orbital fissure in the cranium.
Step-by-step explanation:
The trochlear nerve (cranial nerve IV) is responsible for the contraction of one of the extraocular muscles, and it passes through an opening in the cranium known as the superior orbital fissure. This structure is located at the superior margin of the anterior orbit, lateral to the optic canal.
The superior orbital fissure is an elongated and irregularly shaped fissure that provides passage not only for the trochlear nerve but also for the artery that supplies the eyeball, additional motor nerves controlling eye movements, and sensory nerves.