Question

What is the main function of the glossopharyngeal nerve?

Answer 1

The main function of the glossopharyngeal nerve is to provide sensory, motor and parasympathetic innervation of the posterior third of the tongue, pharynx and parotid gland, and the primary roles of the glossopharyngeal nerve are to initiate swallowing, via the stylopharyngeus muscle and the gag reflex and the glossopharyngeal nerve also controls salivation and detects carotid artery blood pressure.

For the motor function, the glossopharyngeal nerve innervates the stylopharyngeus muscle, which elevates the larynx and pharynx during swallowing.

For sensory function, the glossopharyngeal nerve mediates the gag reflex by providing sensory input from the oropharynx, tonsils and the posterior third of the tongue.

For taste, the glossopharyngeal nerve carries taste sensation from the posterior third of the tongue.

For parasympathetic function, the glossopharyngeal nerve is responsible for secreting saliva from the parotid gland.

And for visceral sensory, the glossopharyngeal nerve monitors blood pressure and chemical composition in the carotid sinus and carotid body.

The glossopharyngeal nerve can heal and can regenerate as like other peripheral nerves, the glossopharyngeal nerve can undergo axonal repair and also reinnervate it's target tissues, like taste buds and somatosensory receptors following an injury.

When the glossopharyngeal nerve is damaged, the proximal end undergoes changes to support axonal growth.

And Schwann cells also proliferate to form pathways or bands of Bungner that guide the regrowing axons toward their original targets.

Peripheral nerve axons often regenerate at a rate of approximately 1 millimeter per day or 1 inch per month.

However the recovery and regeneration of the glossopharyngeal nerve also depends heavily on the severity of the injury or glossopharyngeal nerve damage and if the glossopharyngeal nerve is completely transected or if there is a significant gap, surgery is often needed to bridge the ends of the nerves and facilitate proper regrowth.

The symptoms of glossopharyngeal nerve damage are sudden and severe stabbing pain in your throat, tongue, tonsils and ear.

The symptoms of glossopharyngeal nerve damage often occur on one side and are triggered by talking, swallowing or chewing and can also include , in rare cases fainting or bradycardia.

The key symptoms of glossopharyngeal nerve damage are stabbing, electric shock like or burning pain, which lasts from a few seconds to minutes and the location of the pain is often in the back of the throat or pharynx, tonsillar area, the base of your tongue, ear or voice box also known as your larynx.

The pain with glossopharyngeal nerve damage is often brought on by swallowing, especially of cold liquids, coughing, chewing, yawning or talking.

The physical effects of glossopharyngeal nerve damage are a reduced sensation in your throat, loss of taste on your posterior third of your tongue and a diminished gag reflex.

In rare cases the glossopharyngeal nerve damage can cause heart irregularities, like slow pulse or bradycardia, or a sudden drop in your blood pressure also known as hypotension which can lead to fainting.

When the glossopharyngeal nerve is damaged it can result in and cause difficulty swallowing also known as dysphagia as well as loss of taste or a bitter and or sour taste on the posterior third of your tongue and a reduced sensation in your palate/pharynx as well as an absent gag reflex and reduced salivation.

Damage to the glossopharyngeal nerve can also cause severe pain or neuralgia in your ear, throat or even tongue.

The common symptoms of damage to the glossopharyngeal nerve are dysphagia or difficulty swallowing, which can result in food getting stuck in your throat.

Loss of taste and loss of sensation on the posterior one third of your tongue and palate.

Decreased or absent sensation on your throat, palate and posterior tongue.

Diminished or absent gag reflex

Reduced saliva production, which leads to dry mouth.

And rare cases of a glossopharyngeal nerve being damaged can lead to neuralgia, which results in intense, stabbing pain in your throat, tongue or ear also known as glossopharyngeal neuralgia.

And your uvula might deviate to the side opposite the injury with glossopharyngeal nerve damage.

These symptoms of glossopharyngeal nerve damage often result from injury during procedures such as tonsillectomies or even from compression of the nerve by blood vessels or tumors pressing on the nerves or blood vessels.

The way glossopharyngeal nerve damage is treated through antiseizure medications like carbamazepine.

And antidepressants can help some people and in severe cases, when the pain with glossopharyngeal nerve damage is difficult to treat, surgery may be needed to take the pressure off the glossopharyngeal nerve.

The surgery for glossopharyngeal nerve damage to relieve the pressure off the glossopharyngeal nerve is called microvascular decompression surgery.

The glossopharyngeal nerve can sometimes regenerate through holes in the sieves.

In studies axons of the glossopharyngeal nerve regenerated through holes in the sieves and supported the functional regeneration of taste, thermal and mechanoreceptors.