Inferior salivatory nucleus

The inferior salivatory nucleus, located in the lower pons, is a parasympathetic nucleus integral to the innervation of the parotid gland, thus facilitating saliva production. As a nucleus of the glossopharyngeal nerve (CN IX), it is part of the general visceral efferent category of nuclei, working alongside the nucleus ambiguus and the nucleus of the tractus solitarius.

Afferent connections:

The inferior salivatory nucleus receives input from:

• Hypothalamus: The descending autonomic pathways from hypothalamus influence autonomic responses via connections with parasympathetic nuclei and sympathetic lateral horns.

• The olfactory system, via the reticular formation.

• The nucleus of tractus solitarius: Conveys taste information, linking taste sensations to saliva production.

Efferent connections:

• The inferior salivatory nucleus sends parasympathetic secretomotor fibers via the glossopharyngeal nerve to innervate the parotid gland. Preganglionic fibers travel through the tympanic nerve (branch of glossopharyngeal nerve), passing the tympanic plexus, and proceed via the lesser petrosal nerve to synapse in the otic ganglion. Postganglionic fibers then join the auriculotemporal nerve to reach the parotid gland.