The major salivary glands receive innervation from both parts of the autonomic nervous system - the sympathetic and parasympathetic nervous systems. Also, all major salivary glands receive sensory innervation.

Overall, the autonomic nervous system regulates the produced amount of saliva:

Increased parasympathetic stimulation leads to an increase in the production of saliva.
In contrast, sympathetic stimulation decreases and inhibits secretion, as it also reduces the blood flow through the gland via vasoconstriction (narrowing of the blood vessels).

Parotid gland

The parasympathetic innervation of the parotid gland is provided by the glossopharyngeal nerve (CN IX) (Read more!). The preganglionic fibers arise in the inferior salivatory nucleus in the medulla oblongata.

These glossopharyngeal nerve fibers (CN IX) exit the skull through the jugular foramen to re-enter it as a small branch called the tympanic nerve (Jacobson's nerve). It goes through the tympanic canaliculus to reach the middle ear.

The tympanic nerve then forms the tympanic plexus within the middle ear, which gives off the lesser petrosal nerve that further exits the skull via the foramen ovale. The lesser petrosal nerve then reaches the otic ganglion - a collection of neuronal cell bodies.

The preganglionic fibers synapse in the otic ganglion, and the postganglionic parasympathetic fibers reach the parotid gland via the auriculotemporal nerve (Read more!) that is a branch of the mandibular division of the trigeminal nerve (CN V3).

The sympathetic innervation of the parotid gland is provided by the superior cervical ganglion of the sympathetic trunk (Read more!) Also, the parotid gland receives sensory innervation via the auriculotemporal nerve, and its fascia is innervated by the great auricular nerve.

Unlock with Premium

Innervation of salivary glands (parotid gland)