Mesencephalic nucleus of the trigeminal nerve

The mesencephalic nucleus of the trigeminal nerve is one of three major nuclei that make up the trigeminal sensory nerve nuclear complex along with the main sensory nucleus and the spinal nucleus.

Gross anatomy

The mesencephalic nucleus is a paired structure located at the mesopontine junction which projects cephalad through the midbrain. It is situated along the anterolateral aspect of the periaqueductal grey matter and lies ventral to the inferior colliculi at the level of the midbrain.

It lies superior to the main sensory nucleus of the trigeminal nerve with which it is continuous within the pons.

Innervation

The mesencephalic nucleus contains first-order afferent cells that receive facial proprioceptive impulses from the hard palate, teeth and temporomandibular joint.

A sickle-shaped mesencephalic tract descends to the trigeminal nerve motor nucleus and conveys impulses that control mastication and bite force and also facilitate monosynaptic jaw jerk reflexes.