Lesser petrosal nerve

The Lesser Petrosal Nerve is a nerve in the human body that is part of the parasympathetic nervous system. It is also known as the Jacobson's nerve.

Etymology

The term "petrosal" is derived from the Latin word "petrosus," meaning "rocky," which refers to the nerve's course over the petrous part of the temporal bone. The term "lesser" is used to differentiate this nerve from the greater petrosal nerve, which is a different branch of the facial nerve.

Anatomy

The lesser petrosal nerve originates from the glossopharyngeal nerve (cranial nerve IX) in the inferior salivatory nucleus. It carries preganglionic parasympathetic fibers to the parotid gland, stimulating the secretion of saliva.

Pathway

The lesser petrosal nerve leaves the skull via the foramen ovale and synapses in the otic ganglion. Postganglionic fibers then travel with the auriculotemporal nerve to reach the parotid gland.

Clinical Significance

Damage to the lesser petrosal nerve can result in decreased salivation, a condition known as xerostomia. This can lead to difficulties in swallowing and an increased risk of oral infections.

Related Terms

• Greater petrosal nerve
• Glossopharyngeal nerve
• Parotid gland
• Xerostomia

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