Branches of maxillary nerve to pterygopalatine ganglion

The direct branches of maxillary nerve to pterygopalatine ganglion include two ganglionic nerves (a.k.a. communicating branches).

The pterygopalatine ganglion is a parasympathetic ganglion which is situated inside a region called the pterygopalatine fossa. The ganglion is formed by cell bodies of post-ganglionic parasympathetic neurons. It receives three roots to it, namely the sensory, parasympathetic and sympathetic roots.

The maxillary (V2) nerve–as it hovers over the pterygopalatine ganglion in the pterygopalatine fossa–gives off two short communicating branches called the ‘ganglionic nerves’. These connect with the pterygopalatine ganglion and suspend it inside the fossa.

The general somatic sensory neurons from areas including the face, (mucosa, gums and hard palate of) oral cavity, tonsils, uvula and soft palate, that are travelling through the branches of pterygopalatine ganglion, are eventually communicated to the maxillary nerve via the ganglionic nerves.

The parasympathetic root of pterygopalatine ganglion comprises of preganglionic parasympathetic fibers which arise from the brainstem (superior salivatory nucleus of facial nerve) and travel through the greater petrosal nerve. While, the sympathetic root comprises of postganglionic sympathetic fibers, which come off from the internal carotid artery plexus as the deep petrosal nerve. The deep petrosal nerve merges with the greater petrosal nerve to form the nerve of pterygoid canal (a.k.a. the Vidian nerve), that enters the pterygopalatine fossa to communicate both parasympathetic and sympathetic roots to the pterygopalatine ganglion. The pre-ganglionic parasympathetic neurons synapse with the postganglionic neuronal cell bodies inside the ganglion, whereas the sympathetic neurons–already postganglionic by this time–pass unimpeded through the pterygopalatine ganglion.

From the ganglion–like the sensory root–both postganglionic parasympathetic and sympathetic neurons types also use the ‘ganglionic branches’ as portals, to reach maxillary nerve. The autonomic neurons, subsequently travel through the maxillary and ophthalmic divisions of the trigeminal nerve to provide secretomotor signals to the lacrimal gland, mucous membranes of the nasal cavity, nasopharynx, oropharynx, upper oral cavity and some meningeal and cerebral blood vessels.

To conclude, the direct branches of maxillary nerve to pterygopalatine ganglion include the two ganglionic or communicating branches, which contain three types of neurons, including the general somatic afferent neurons, and the postganglionic parasympathetic and postganglionic sympathetic neurons.