 Before the nerve exits the skull via the stylomastoid foramen and after the nerve to the stapedius muscle has branched off, the facial nerve gives off the chorda tympani nerve.This nerve exits the skull through the Petrotympanic fissure and merges with the lingual nerve, after which it synapses with neurons in the submandibular ganglion.These postganglionic neurons provide parasympathetic innervation to the submandibular and sublingual glands.