Fourth Cranial Nerve (Noun)
Meaning
Either of the two cranial nerves on either side that control the superior oblique muscles of the eyes.
Classification
Nouns denoting body parts.
Examples
- The fourth cranial nerve is a mixed nerve that contains both sensory and motor fibers.
- The fourth cranial nerve originates in the brainstem and emerges between the posterior cerebral artery and the superior cerebellar artery.
- The superior oblique muscle, controlled by the fourth cranial nerve, rotates the eyeball downward and outward.
- Damage to the fourth cranial nerve can cause diplopia, or double vision, when looking downward.
- In clinical examination, the function of the fourth cranial nerve is often tested by having the patient look downward and outward.