Emergency Medical Technician (EMT) Intermediate Practice Exam

Which function is associated with the trigeminal nerve (cranial nerve V)?

1. Provides sensory innervation to the face

2. Provides motor innervation to the muscles of chewing

3. Innervates the muscles of facial expression

4. Controls eye movements

The correct answer is: Provides motor innervation to the muscles of chewing

The trigeminal nerve, also known as cranial nerve V, is primarily involved in both sensory and motor functions related to the face. One of its key roles is to provide motor innervation to the muscles of mastication, which are responsible for chewing. This includes the masseter and temporalis muscles, among others. While the trigeminal nerve does provide sensory innervation to the face through its three branches (ophthalmic, maxillary, and mandibular), the primary function being highlighted in the choice is its motor control. The role in sensory innervation of the face is significant but is a distinct function from the motor aspect that is being addressed in this context. Other options, such as innervating the muscles of facial expression or controlling eye movements, are functions associated with different cranial nerves. The facial nerve (cranial nerve VII) manages muscles of facial expression, while the oculomotor nerve (cranial nerve III) is responsible for eye movements. Therefore, the focus on chewing and the specific motor innervation to the relevant muscles aligns correctly with the primary role of the trigeminal nerve.