The trigeminal motor nucleus contains

motor neurons A motor neuron (or motoneuron or efferent neuron) is a neuron whose cell body is located in the motor cortex, brainstem or the spinal cord, and whose axon (fiber) projects to the spinal cord or outside of the spinal cord to directly or indirectly ...

that innervate muscles of the

first branchial arch The pharyngeal arches, also known as visceral arches'','' are structures seen in the embryonic development of vertebrates that are recognisable precursors for many structures. In fish, the arches are known as the branchial arches, or gill arch ...

, namely the muscles of

mastication Chewing or mastication is the process by which food is crushed and ground by teeth. It is the first step of digestion, and it increases the surface area of foods to allow a more efficient break down by enzymes. During the mastication process, th ...

, the

tensor tympani The tensor tympani is a muscle within the middle ear, located in the bony canal above the bony part of the auditory tube, and connects to the malleus bone. Its role is to dampen loud sounds, such as those produced from chewing, shouting, or thunde ...

tensor veli palatini The tensor veli palatini muscle (tensor palati or tensor muscle of the velum palatinum) is a broad, thin, ribbon-like muscle in the head that tenses the soft palate. Structure The tensor veli palatini is found anterior-lateral to the levator ve ...

, mylohyoid, and anterior belly of the

digastric The digastric muscle (also digastricus) (named ''digastric'' as it has two 'bellies') is a small muscle located under the jaw. The term "digastric muscle" refers to this specific muscle. However, other muscles that have two separate muscle bellie ...

. This nucleus is located in the mid-pons (i.e. in the center of the pons going inferior to superior).Brainstem Nuclei of the Cranial Nerves at wustl.edu

Lesion

The trigeminal motor nucleus forms the efferent pathway of the

jaw jerk reflex The jaw jerk reflex or the masseter reflex is a stretch reflex used to test the status of a patient's trigeminal nerve ( cranial nerve V) and to help distinguish an upper cervical cord compression from lesions that are above the foramen magnum. The ...

. Since the axons involved in this reflex do not decussate, a lesion involving the trigeminal motor nucleus would cause ipsilateral hemiparesis.

References

External links

Washington University
Cranial nerve nuclei Trigeminal nerve Pons {{Neuroanatomy-stub