What is the primary function of the Mandibular Nerve (CN V3)?

The primary function of the Mandibular Nerve, which is the third division of the trigeminal nerve (cranial nerve V), encompasses both sensory and motor components. It provides sensory innervation to the lower jaw, including the skin over the mandible, the lower lip, and anterior 2/3 of the tongue, along with motor innervation to the muscles of mastication such as the masseter, temporalis, and pterygoid muscles. This dual role allows it to facilitate actions related to chewing (motor) as well as sensations from the lower regions of the face (sensory).

Understanding this function helps to appreciate the Mandibular Nerve's role in both mastication and sensory perception in the lower facial region, distinguishing it from other cranial nerves which may have more limited or specialized functions.