What does the trochlear nucleus control?

What does the trochlear nucleus control?

• A. Eyeball/eye movement
• B. Jaw movement
• C. Tongue movement
• D. Hearing

Answer: (A)

The trochlear nucleus is the motor center for the fourth cranial nerve, which innervates the superior oblique muscle of the eye. This muscle helps move the eyeball—primarily depressing the eye when it is turned inward (adducted) and contributing to intorsion. So the main function controlled by this nucleus is eyeball movement. Jaw movement is handled by the trigeminal motor nucleus, tongue movement by the hypoglossal nucleus, and hearing by the vestibulocochlear system, not by the trochlear nucleus.

The trochlear nucleus is the motor center for the fourth cranial nerve, which innervates the superior oblique muscle of the eye. This muscle helps move the eyeball—primarily depressing the eye when it is turned inward (adducted) and contributing to intorsion. So the main function controlled by this nucleus is eyeball movement.

Jaw movement is handled by the trigeminal motor nucleus, tongue movement by the hypoglossal nucleus, and hearing by the vestibulocochlear system, not by the trochlear nucleus.