Cranial Nerve seven (CN VII) is also known as the Facial Nerve. Fibers of this nerve exit the skull and course down the jaw (not inside!), with a branch traveling through the middle ear (chorda tympani ). The main fibers of the facial nerve enter the parotid gland and immediately diverge into five branches, remembered by this pneumonic: Ten Zebras Bit My Cat = Temporal, Zygomatic , Buccal , Mandibular , and Cervical; the facial nerve also gives off an Occipital and a Posterior Auricular branch before entering the parotid gland.
The facial nerve (CN VII) is responsible for providing you with two things: facial movements and taste. The major function of CN VII is to supply motor innervation to the muscles of facial expression , allowing you to squint your eyes, raise your eyebrows, and smile. CN VII also monitors the anterior two-thirds of your tongue for taste, including sour, sweet, bitter, and salty tastes. (The Glossopharyngeal nerve / CN IX supplies taste receptors to the posterior one-third of the tongue, and the Vagus nerve / CN X has a few taste receptors on the epiglottis.) A prevelent mistake amoung students of human anatomy is to assume that the facial nerve is responsible for facial sensations; this job is reserved for another cranial nerve (Trigeminal / CN V ), which just so happens to also control the muscles of mastication.
