Submandibular ganglion

The submandibular ganglion is situated underneath the mandible in the neck, on the lateral surface of hyoglossus muscle. It is formed by cell bodies of post-ganglionic parasympathetic neurons.

The submandibular ganglion is topographically connected to the lingual branch of mandibular nerve. It also possesses a strong functional connection with the facial nerve.

The submandibular ganglion receives parasympathetic and sympathetic roots:

The parasympathetic root comprises of preganglionic parasympathetic neurons, which arise from the superior salivatory nucleus of facial nerve. These secretomotor neurons are conveyed by the chorda tympani nerve to the lingual nerve, as the latter descends in the infratemporal fossa. While the preganglionic parasympathetic neurons course through the lingual nerve, they get relayed inside the submandibular ganglion. Thereupon, the post-ganglionic parasympathetic fibers either pass directly to the submandibular gland or a few might hop back on to the lingual nerve to innervate the more anteriorly situated sublingual gland.

The postganglionic sympathetic fibers constitute the sympathetic root (that arise from the superior cervical ganglion) and travel via the plexus around the facial artery to reach the submandibular ganglion. They traverse unrelayed through the ganglion to offer vasomotor innervation to the submandibular and sublingual salivary glands; causing vasoconstriction and reducing secretions.