[TA] the parasympathetic root of the otic ganglion, derived from the tympanic plexus; it leaves the tympanic cavity through the canal for the lesser petrosal nerve and passes within the cranium to the sphenopetrosal fissure, or to the foramen ovale, or to the petrosal foramen through which it descends to reach the otic ganglion; conveys presynaptic parasympathetic fibers from the glossopharyngeal nerve concerned with secretomotor innervation of the parotid gland. SYN: nervus petrosus minor [TA], parasympathetic root of otic ganglion*, radix parasympathica ganglii otici*, lesser superficial petrosal nerve.