trochlear
Noun: 1. Trochlear nerve: The fourth cranial nerve (CN IV). It is a motor nerve that controls the superior oblique muscle of the eye, which is responsible for moving the eye downward and outward (especially when the eye is turned inward).
The word "trochlear" is primarily used in medical and anatomical contexts to refer specifically to this nerve. It is often used with the word "nerve." * The trochlear nerve has the longest intracranial course of any cranial nerve. * Damage to the trochlear nerve can cause double vision and a head tilt. * The physician tested the function of the trochlear nerve.
- Trochlear nucleus: The cluster of nerve cell bodies in the brainstem from which the trochlear nerve originates.
- Trochlear palsy/paralysis: A condition characterized by weakness or paralysis of the superior oblique muscle due to damage to the trochlear nerve.
- Trochlea (noun): A general anatomical term for a pulley-shaped structure. The superior oblique muscle tendon passes through a fibrous loop called the trochlea, which is how the nerve gets its name.
- Trochlear (adjective): Pertaining to a trochlea. For example, the trochlear surface of a bone.
- Cranial nerve IV
- Fourth cranial nerve
The word "trochlear" almost exclusively refers to the cranial nerve in modern English usage. Its use as a standalone noun ("the trochlear") is a shorthand for "the trochlear nerve." Its other uses are highly specialized anatomical adjectives.
- either of the two cranial nerves on either side that control the superior oblique muscles of the eyes