The pterygopalatine ganglion lies at the anterior wall of the pterygopalatine fossa below the maxillary nerve, which gives off ganglionic branches (pterygopalatine nerves) to the ganglion (sensory root). The parasympathetic secretory fibers (13) from the superior salivatory nucleus extend in the facial nerve (intermediate nerve) up to the genu of the facial nerve where they branch off as the greater petrosal nerve. The nerve passes through the foramen lacerum to the base of the skull and through the pterygoid canal to the ganglion (parasympathetic root). Sympathetic fibers from the carotid plexus form the deep petrosal nerve (sympathetic root) and join the greater petrosal nerve to form the nerve of the pterygoid canal.
The branches leaving the pterygopalatine ganglion carry secretory fibers for the lacrimal gland and for the glands of the nasal cavity. The parasympathetic fibers for the lacrimal gland synapse in the ganglion. The postganglionic fibers run in the ganglionic branches to the maxillary nerve (AB11) and reach the lacrimal gland via the zygomatic nerve and its anastomosis with the lacrimal nerve. The remaining parasympathetic secretory fibers run in the orbital branches to the posterior ethmoidal cells, in the lateral posterior nasal branches to the nasal conchae, in the nasopalatine nerve across the nasal septum and through the incisive canal, and in the palatine nerve to the hard and soft palates. The taste fibers for the soft palate run in the palatine nerves and in the greater petrosal nerve.