Branches of mandibular nerve to otic ganglion - e-Anatomy - IMAIOS

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The neuronal branches of mandibular nerve to otic ganglion come via its sensory, parasympathetic, sympathetic and motor roots.Please note that the otic ganglion is a parasympathetic ganglion formed by cell bodies of postganglionic parasympathetic fibers. It is situated close to the main trunk of the mandibular nerve (V3), inside the infratemporal fossa and just inferior to the foramen ovale.Sensory root: The auriculotemporal nerve–which is a branch of the posterior division of mandibular nerve (V3)–gives off a sensory root to the otic ganglion. Some general somatic sensory neurons from the capsule and fascia of parotid gland, pass ‘unrelayed’ through the otic ganglion and its sensory root to reach the auriculotemporal nerve. These sensory neurons transmit sensations of pain, touch, temperature and pressure and end up as far as the sensory trigeminal ganglion via this route.Parasympathetic root: The parasympathetic root to otic ganglion is secretomotor and comes off from the lesser petrosal nerve. The preganglionic parasympathetic neurons follow the following route to reach the otic ganglion:Origin from the inferior salivatory nucleus of facial nerve > via tympanic branch of glossopharyngeal nerve > tympanic plexus (middle ear) > lesser petrosal nerve (passes via foramen ovale) > otic ganglion (in infratemporal fossa).Next, the post-ganglionic neurons from the otic ganglion hop onto the auriculotemporal nerve–a branch of V3–to end up providing secretomotor innervation to the parotid gland mainly.Sympathetic root: The sympathetic root arises from the sympathetic plexus around the middle meningeal artery. It contains post-ganglionic sympathetic neurons which arise from the superior cervical ganglion. They pass through otic ganglion without relay and hop onto the auriculotemporal nerve. Here, they run along with the postganglionic sympathetic neurons to eventually end up reaching the parotid gland. Sympathetics lead to vasoconstriction of parotid vessels, thus decreasing secretions.Motor root: The nerve to medial pterygoid muscle–which is a branch of the main trunk of V3–gives off a motor root to the otic ganglion. Some somatic motor neurons from the V3 reach the otic ganglion via the motor root. These efferent neurons pass ‘unrelayed’ through the ganglion and end up innervating two muscles, including the tensor tympani and the tensor veli palatini muscles.