THE SUPERIOR SALIVARY NUCLEUS
(or superior salivatory nucleus) of the facial nerve is a visceromotor cranial nerve nucleus located in the pontine tegmentum.
Parasympathetic efferent fibers of the facial nerve (preganglionic fibers) arise according to some authors from the small cells of the facial nucleus, or according to others from a special nucleus of cells scattered in the reticular formation, dorso-medial to the facial nucleus. This is sometimes called the superior salivatory nucleus.
These preganglionic fibers are distributed partly via the chorda tympani and lingual nerves to the submandibular ganglion, thence by postganglionic (vasodilator) fibers to the submandibular gland and sublingual gland.
Some of the preganglionic fibers pass to the pterygopalatine ganglion via the greater petrosal nerve.
The term "lacrimal nucleus" is sometimes used to refer to a portion of the superior salivary nucleus.
INFERIOR SALIVATORY NUCLEUS
the inferior salivatory nucleus is a cluster of neurons controlling the parasympathetic input to the parotid gland. It is one of the components of the glossopharyngeal nerve (cranial nerve IX).
Its precise location in humans has not yet been identified, but in other mammals it is located in the medulla within the general visceral efferent cell column, superior to the nucleus ambiguus and inferior to the superior salivatory nucleus.
While still in the medulla, fibers of the inferior salivatory nucleus join with fibers of the gustatory nucleus, nucleus ambiguus, and spinal nucleus of the trigeminal nerve, and exit the medulla as the mixed glossopharyngeal nerve (cranial nerve IX). It sends fibers through the glossopharyngeal nerve's tympanic nerve and into the tympanic plexus. Exiting the plexus within the lesser petrosal nerve, these preganglionic fibers synapse with cells in the otic ganglion, which send postganglionic fibers into the mandibular division of the trigeminal nerve, then into the auriculotemporal nerve, finally reaching their target, the parotid gland.
Parasympathetic input from fibers of the inferior salivatory nucleus stimulates the parotid gland to vasodilate and secrete