The petrosal nerve minor is a part of the IX cranial nerve. It is located in the posterior part of the brain. Its function is to supply the parotid gland.
What is the petrosal nerve minor?
The petrosal minor nerve is a nerve located inside the skull. It belongs to the branches of the IXth of a total of XII. Cranial Nerves. The IXth cranial nerve is the glossopharyngeal nerve. It innervates with its branches all areas related to the swallowing process. The petrosal minor nerve, together with the tympanic nerve, provides the Jacobsen anastomosis. The nerves supply the parotid gland and the eustachian tube. The parotid gland is called the parotid gland. The eustachian tube is the tuba auditiva. The parotid gland supplies saliva to the entire mouth and jaw area. This is important in speech formation and chewing. The saliva is rich in enzymes and proteins. The tuba auditiva provides air pressure equalization in the ear and nasopharynx. The equalization of pressure makes hearing possible. In addition, it is important for the secretions formed in the ear to drain. Without the petrosal minor nerve, neither organ could fully perform its activities.
Anatomy and structure
The IXth cranial nerve is the glossopharyngeal nerve. This exits the brainstem and travels downward to the jugular foramen. The foramen is a small opening at the posterior cranial cavity. As the glossopharyngeal nervem passes through the foramen jugulare, it forms two ganglia. These are the superius ganglion and the inferior ganglion. From the inferior ganglion, the fibers continue through the tympanic canal of the petrous bone to the tympanic cavity of the middle ear. There, sympathetic fibers are picked up from the carotid plexus and the tympanic plexus is formed from all the fibers. This sensitively supplies the middle ear and the auditory tube. From the tympanic plexus, the petrosal minor nerve branches off. It passes back into the cranial cavity, where it passes under the dura mater. Through the lacerated foramen, the petrosal nerve leaves the interior of the skull and travels to the infratemporal fossa. It finally terminates at the otic ganglion. There its parasympathetic fibers are connected. These then move on to the parotid gland. This is the parotid gland. Together with the tympanic nerve, which arises from the glossopharyngeal nevus, the petrosal minor nerve forms the Jacobson anastomosis.
Function and Tasks
The petrosal nerve has an important role in supplying organs in the region of the ear. It innervates the auditory tuba as well as the parotid gland. Both organs can carry out their activities through the petrosal nerve. The auditory tube is responsible for equalizing pressure in the ear. This is essential for hearing. Without it, the sound waves picked up by the pinna would not be adequately transmitted. The parotid gland produces ¼ of all saliva in the human body. The flow of saliva is called salivation. The posterior region of the tongue receives the saliva it produces. This is where part of the sensation of taste takes place. The saliva produced is thin. It is involved in the decomposition of nutrients, which is significant for the chewing process. The saliva contains immunoglobulins. These are defense bodies, which provide immunological defense in the mouth and pharynx. It provides extensive protection against bacteria and keeps the oral flora in balance. The mucous membranes, teeth and gums are protected by saliva. Thanks to its watery structure, it reaches the interdental spaces, where it also provides extensive protection against bacteria and viruses. The activities of the auditory tube and the parotid gland play an important role in speech formation. Without them, nasal pronunciation would occur. This applies to both the singing and speaking voices.
Diseases
Diseases associated with the lesser petrosal nerve include nerve pain. These are called neuralgias and cause the patient to experience sudden onset of pain. These occur in the petrosal minor nerve throughout the ear. Neuralgia within the fibers of the lesser petrosal nerve can cause a breakdown in the overall functional activity of the fibers. This would cause the parotid gland as well as the tuba auditiva to no longer be adequately supplied and be restricted in their respective activities.Since the parotid gland is responsible for the flow of saliva in the mouth and jaw, there would be problems with chewing as well as swallowing. Saliva regulates the oral flora and is an important element in speech formation. The auditory tube balances the pressure between the middle ear and the nasopharynx. It is also an important element in the drainage of ear secretions. If brain swelling occurs, it can cause the lesser petrosal nerve to become pinched. Entrapment of the nerve also causes a reduction in its ability to function and would equally affect the activity of the parotid gland as well as the auditory tube. Brain swelling can be caused by accidents, surgical procedures, tumors, or falls. In case of fractures at the skull bone, for example in the area of the foramen jugulare, it can happen that the opening of the skull is closed. If this is the case, the nerve can no longer pass through the base of the skull. This also leads to functional disorders. In addition, fractures can damage nerve fibers as they occur and cause its failure.