The trigeminal motor nucleus is located in which region?

The trigeminal motor nucleus is located in which region?

• A. Upper pons
• B. Lower pons
• C. Medulla
• D. Midbrain

Answer: (A)

The trigeminal motor nucleus sits in the pontine tegmentum, in the upper portion of the pons. This is where the motor neurons that innervate the muscles of mastication (and a few other first-arch muscles) reside and give rise to the motor root of the trigeminal nerve to reach those muscles. Because this nucleus is located in the upper pons, that region is the correct one. The midbrain and medulla house other cranial nerve motor nuclei, and the lower pons would be too caudal to contain the trigeminal motor nucleus.

The trigeminal motor nucleus sits in the pontine tegmentum, in the upper portion of the pons. This is where the motor neurons that innervate the muscles of mastication (and a few other first-arch muscles) reside and give rise to the motor root of the trigeminal nerve to reach those muscles. Because this nucleus is located in the upper pons, that region is the correct one. The midbrain and medulla house other cranial nerve motor nuclei, and the lower pons would be too caudal to contain the trigeminal motor nucleus.