Glossopharyngeal Nerve (Human Anatomy): Image, Functions, Diseases and Treatments

This nerve is the ninth of 12 cranial nerves (CN IX). It provides your mouth and throat with motor, parasympathetic, and sensory information. Among its various tasks, the nerve raises a portion of the throat to facilitate swallowing.

Part of what makes up your nervous system are things called nerves, which are bundles of fibres that resemble thread. These fibres are used by the chemical and electrical messengers (neurons) in your brain to communicate with one another. Your brain is able to communicate with other areas of your body thanks to your nervous system.

There are a total of 12 cranial nerves, and the glossopharyngeal nerve is the ninth of those nerves (CN IX). These nerves originate in the brainstem of your body. They have connections to the many muscles, organs, and other structures that are found in the mouth and throat. These nerves are connected to one another in a pair, thus there is one on each side.

The glossopharyngeal nerve reaches its conclusion deep within the interior of the neck, close to the base of the throat. Swallowing is one of the many functions that this organ performs. In addition to this, it is one of the very few nerves in your body that has all three types of fibres:

• Motor: Enables muscle movement.
• Parasympathetic: Helps tissue and organs rest when not in use.
• Sensory: Provides sensation, so you can detect taste, touch and temperature.

The beginning of the glossopharyngeal nerve can be found in the base of your brainstem (medulla oblongata). Before reaching your pharynx, it travels through a variety of structures located in your neck (throat).

Its path includes:

• Getting out of your head through a narrow passageway (jugular foramen).
• Following the course of your jugular vein as it descends down your neck.
• Moving posterior to the styloid process, which is a sharp bone in the base of the skull, just below the ear.
• Having a forward curve and coming into contact with the stylopharyngeus (near your throat).
• In order to go behind the hyoglossus muscle. This muscle allows you to descend your tongue and drag it toward the rear of your mouth, both of which are beneficial functions of the tongue.

There are a variety of functions that are performed by the glossopharyngeal nerve. Near your throat are a number of muscles, organs, and bodily functions that are controlled by a nerve called the glossopharyngeal nerve.

• Carotid sinus: This hollow region facilitates blood flow from the brain to the carotid artery located in the neck of the body. It plays a part in maintaining a healthy blood pressure.
• Middle ear: You are able to recognise when you are full as a result of fluid accumulation because you have sensory nerve fibres. Pain is another symptom that may accompany an ear infection.
• Parotid (saliva) gland: After you have finished eating, CN IX will reduce the amount of saliva that you produce.
• Part of the tongue: The glossopharyngeal nerve is responsible for facilitating the tasting of food in the posterior portion of the tongue.
• Stylopharyngeus muscle: A lengthy muscle that can be found running down a portion of your throat. This muscle is connected to CN IX, which helps elevate the voice box (larynx) and the surrounding throat (pharynx). Because of this, it is now feasible to swallow.
• Tonsils: You are able to feel the discomfort of a sore throat or the swelling caused by an infection thanks to the sensory nerve fibres in your body.

Many conditions can affect CN IX, some of which can impact quality of life. They include:

• Glossopharyngeal neuralgia (GPN): Sneezing, eating, swallowing, and other activities might induce periods of severe discomfort in your throat, the back of your tongue, or even your middle ear. Eating can be tough if you are afraid of further attacks.
• Glossopharyngeal nerve palsy: The functionality of the CN IX nerve is impacted when it is injured or when a medical condition is present. The nerve may become partially or completely paralysed, which means that it is unable to perform its normal functions. A stroke can sometimes result in complications such as glossopharyngeal nerve palsy.
• Glossopharyngeal neuralgia: This is a disorder that is characterised by extreme discomfort at the back of the neck and the tongue, which can come and go at will. Swallowing, speaking, or even just yawning might bring on the excruciating discomfort.
• Neuritis: An inflammation of the glossopharyngeal nerve can result in tingling, numbness, and weakness in the throat and tongue. This condition is known as glossopharyngitis.
• Trauma: Physical trauma, such as a blow to the head or neck, can cause damage to the glossopharyngeal nerve. The damage might be permanent or temporary.
• Tumours: When tumours grow close to the glossopharyngeal nerve, they have the potential to injure or compress the nerve, which can result in symptoms such as numbness or weakness in the throat and tongue.
• Multiple sclerosis: This inflammatory condition can have an effect on the glossopharyngeal nerve, which can lead to symptoms such as difficulties swallowing and changes in taste.
• Bell's palsy: This condition causes the muscles on one side of the face to become temporarily weak or paralysed. It can affect either side of the face. Inflammation or damage to the facial nerve (cranial nerve VII), which may also affect the glossopharyngeal nerve, can be the cause of this condition. It can also occur on its own. Symptoms may include difficulties in speaking, swallowing, and eating, in addition to alterations in one's sense of taste.
• Guillain-Barre syndrome: This is an inflammatory condition that leads to inflammation of the nerves, which in turn causes a loss of sensation and weakness in the muscles. It is possible for it to impact the glossopharyngeal nerve, which can lead to changes in taste as well as trouble swallowing.
• Meningitis: This condition is characterised by an infection of the membranes that surround the brain and spinal cord. It is possible for it to induce inflammation of the cranial nerves, particularly the glossopharyngeal nerve, which can result in symptoms such as trouble swallowing and alterations in taste.
• Stroke: A stroke can cause damage to the brain as well as weakness or paralysis on one side of the body, which can include the neck and the tongue. This can have an effect on the glossopharyngeal nerve, which in turn can make it difficult to swallow and talk.
• Complications from medical procedures such as:
• Carotid endarterectomy: The fatty accumulation in your carotid artery will be removed during this treatment. This conduit brings oxygen-rich blood to the brain of the patient. The carotid artery is located relatively close to the glossopharyngeal nerve as it travels through the neck.
• Laryngeal mask airway placement: A tube that medical professionals insert through the patient's mouth and into the upper section of the patient's throat. It may provide you with oxygen or sedatives to help you fall asleep. It is possible for the tube to cause damage to sensitive tissue in the throat, particularly the glossopharyngeal nerve.
• Tonsillectomy: After having their tonsils removed, some patients report symptoms of Eagle syndrome. This syndrome develops when there is an overabundance of scar tissue in the surrounding area, which strains the cranial nerve fibres. It's possible that you'll feel discomfort in your ear, as well as in your throat and neck.

A variety of diagnostic procedures in the laboratory can evaluate the glossopharyngeal nerve, also known as CN IX. These tests can assist in the diagnosis of any conditions affecting the glossopharyngeal nerve, including injury of any kind. Common diagnostic procedures for the glossopharyngeal nerve include the following:

• Glossopharyngeal nerve conduction study: During this test, the speed and strength of the electrical signals produced by the nerve will be measured. During the procedure, electrodes are positioned on the skin above the nerve, and the reaction to a minute electrical current that is transmitted through the nerve is measured.
• Glossopharyngeal nerve function test: As part of this examination, the glossopharyngeal nerve will be stimulated, and the reaction of the muscles that it controls will be measured. For instance, the nerve can be stimulated by touching the back of the throat, and the response can be measured by observing movement in the muscles of the throat and tongue. Similarly, the nerve can be stimulated by applying heat to the back of the throat.
• Glossopharyngeal nerve imaging: Imaging methods such as MRI (magnetic resonance imaging) and CT (computed tomography) are utilised during this test in order to visualise the glossopharyngeal nerve and the structures that are located in its immediate vicinity.
• Glossopharyngeal nerve biopsy: When diagnosing illnesses or injury to the glossopharyngeal nerve, it is sometimes necessary to extract a tiny tissue sample from the nerve and examine it under a microscope. This is only done in extremely unusual circumstances.

• Glossopharyngeal nerve decompression: This treatment is carried out in order to alleviate pressure that has been placed on the glossopharyngeal nerve as a result of either edoema or a tumour.
• Glossopharyngeal nerve resection: During this treatment, a section of the glossopharyngeal nerve will be cut away. In the event that the nerve is sick or injured, this procedure can be required.
• Glossopharyngeal nerve reconstruction: During this surgery, a glossopharyngeal nerve that has been injured will either be repaired or reconstructed. Nerve grafts or maybe other procedures could be used to accomplish this goal.
• Glossopharyngeal nerve block: As part of this operation, a local anaesthetic will be injected into the region surrounding the glossopharyngeal nerve in order to numb the nerve and give pain relief.

• It's probable that some of the factors that lead to CN IX sickness can't be avoided. It is not always possible to determine what causes some conditions, such as glossopharyngeal neuralgia.
• It is crucial to locate an experienced surgeon if you require a medical procedure to repair an issue near the CN IX. The best option is to look for doctors who have extensive experience carrying out the surgery that you require.
• Certain diseases, such as those that affect your oral cavity and throat, can be avoided by taking the appropriate precautions. The following are some of the measures you can take to reduce the risk:
• Stop using tobacco if smoking is something you do.
• Keeping tabs on how much and how frequently you consume alcoholic beverages.
• Obtaining the vaccine against the human papillomavirus (HPV).
• Keeping a healthy lifestyle that includes eating a balanced food and being active on a regular basis.

• If you encounter any of the following, please contact your healthcare provider:
• Having a hard time swallowing (dysphagia).
• You may have discomfort or be unable to open your mouth.
• Oral parchedness
• A dulling of the sensation at the back of your mouth.
• Weakened or nonexistent gag reflex.

• Steroids for reducing inflammation of glossopharyangeal nerve: Steroids are drugs used to reduce inflammation in the body. Prednisone, methylprednisolone, and azathioprine are a few examples of steroids that can be utilised to treat inflammation of the glossopharyngeal nerve.
• Analgesics for pain in the Glossopharyngeal Nerve: Analgesics are pain-relieving drugs. Acetaminophen, ibuprofen, and morphine are examples of analgesics that can be utilised to treat glossopharyngeal nerve discomfort.
• Muscle relaxants for Glossopharyngeal Nerve Stiffness: Muscle relaxants are drugs used to alleviate muscle stiffness and spasms. Meprobamate, diazepam, and carisoprodol are examples of muscle relaxants that may be used to relieve stiffness in the glossopharyngeal nerve.
• Antibiotics for Glossopharyngeal Nerve Infection: Antibiotics are drugs used to treat infections caused by bacteria. Antibiotics such as penicillin, amoxicillin, and ciprofloxacin can be utilised to treat an infection of the glossopharyngeal nerve.
• Nutritional Supplements for Glossopharyngeal Nerve Pain Reduction: Nutritional supplements are substances that are taken orally to offer nutrients that may be lacking or in insufficient amounts in the diet. Omega-3 fatty acids, magnesium, and vitamin D are a few examples of dietary supplements that can be utilised to alleviate glossopharyngeal nerve discomfort.
• Antivirals for the treatment of Glossopharyngeal Nerve infection: Antivirals are drugs used to treat viral infections. Acyclovir, zidovudine, and lamivudine are examples of antivirals that may be used to treat an infection of the glossopharyngeal nerve.
• Chemotherapeutic medicines for Glossopharyngeal Nerve: Paclitaxel, docetaxel, and carboplatin are examples of chemotherapeutic medications that may be used to treat disorders of the glossopharyngeal nerve.