The inferior view of the brain, highlighting the cranial nerves and their functions. The olfactory nerve (CN I) enables the olfactory system and one's sense of smell. The optic nerve (CN II) enables sight and transmits visual information. The oculomotor nerve (CN III) is responsible for all eye muscles, except for the superior oblique and external rectus muscle. The trochlear nerve (CN V) enables sensory to the face, sinuses, and teeth including the chewing muscles. The abducens nerve (CN VI) innervates the external rectus muscle of the eye. The facial nerve (CN VII) enables the muscles of facial expression. The vestibulocochlear nerve (CN VIII) enables balance and hearing. the glossopharyngeal nerve (CN IX) is responsible for sensory to the posterior tongue, tonsils, and pharynx. The vagus nerve (CN X) enables sensory and muscular innervation to the heart, lungs, bronchi, digestive system, trachea, larynx, pharynx, and the external ear. The accessory nerve (CN XI) innervates the sternocleidomastoid and trapezius muscles. The hypoglossal nerve (CN XII) innervates the muscles of the tongue.
