Superior oblique muscle

Superior Oblique Muscle

The superior oblique muscle is one of the extraocular muscles responsible for eye movement. (Image from Gray's Anatomy)

The Superior Oblique Muscle is one of the extraocular muscles responsible for the movement of the eye. It is innervated by the trochlear nerve (cranial nerve IV), the only cranial nerve that decussates and the only one that emerges dorsally from the brainstem.

Structure

The superior oblique muscle originates in the upper, medial side of the orbit and loops through the trochlea of superior oblique, a cartilaginous loop, which redirects the muscle's force downward and laterally.

Function

The primary function of the superior oblique muscle is to produce intorsion, depression and abduction of the eye. It is the only extraocular muscle that, when activated, has the ability to pull the eye in a direction that is not parallel to its long axis.

Clinical significance

Damage to the superior oblique muscle or its innervating trochlear nerve can result in a condition known as superior oblique palsy. This condition is characterized by the eye drifting upward and can cause diplopia (double vision).

See also

• Inferior oblique muscle
• Extraocular muscles
• Trochlear nerve
• Superior oblique myokymia