Their neurons give rise to preganglionic parasympathetic nerve fibers in the control of salivation.

[5] Preganglionic fibers en route to the pterygopalatine ganglion (destined to ultimately innervate the lacrimal gland and the mucosal glands of the nose, palate, and pharynx) subsequently form the greater petrosal nerve, whereas those en route to the submandibular ganglion (destined to ultimately innervate the submandibular and sublingual salivary glands) subsequently form the chorda tympani.

It is the general visceral efferent (GVE) component of the glossopharyngeal nerve supplying the parasympathetic input to the parotid gland for salivation.

Here, the fibres synapse, and the postganglionic fibers pass by communicating branches to the auriculotemporal nerve, which conveys them to the parotid gland.

Parasympathetic input from fibers of the inferior salivatory nucleus stimulates the parotid gland to produce vasodilation and secrete saliva.