Certified Ophthalmic Medical Technologist (COMT) Practice Exam

Which extraocular muscle is responsible for intorsion, depression, and abduction?

1. Superior Rectus

2. Superior Oblique

3. Inferior Oblique

4. Inferior Rectus

The correct answer is: Superior Oblique

The superior oblique muscle is primarily responsible for intorsion (inward rotation), depression (downward movement), and abduction (movement away from the midline) of the eye. This muscle originates in the back of the orbit and passes through a fibrocartilaginous structure called the trochlea, allowing it to create the required torque for these specific eye movements. When the superior oblique contracts, it pulls the eyeball in a way that causes the top of the eye to rotate downward and inward. This intricate movement is essential for proper alignment and coordination of binocular vision, allowing the eyes to work together during tasks like reading or observing objects at different distances. Other extraocular muscles perform different functions; for instance, the superior rectus primarily elevates and assists with intorsion and adduction of the eye, the inferior oblique elevates and also contributes to abduction and extorsion, while the inferior rectus mainly depresses the eye and contributes to adduction. Understanding these specific roles aids in recognizing the unique contributions of each muscle to overall eye movement.