Glossopharyngeal Nerve

What are nerves?

Nerves are bundles of thread-like fibers that make up part of your nervous system. Your brain’s chemical and electrical messengers (neurons) travel along these fibers. Nerves help your brain communicate with different parts of your body.

What is the glossopharyngeal nerve?

The glossopharyngeal nerve is the ninth of 12 cranial nerves (CN IX). These nerves start in your brainstem. They connect to organs, muscles and other structures in your mouth and throat. These nerves are paired — there’s one on each side.

The glossopharyngeal nerve ends deep inside of your neck near the back of your throat. Among its many functions, it enables swallowing. It’s also one of the few nerves in your body with three types of fibers:

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

What is the function of the glossopharyngeal nerve?

There are many glossopharyngeal nerve functions. The glossopharyngeal nerve affects muscles, organs and body processes near your throat, such as the:

• Carotid sinus: This hollow area helps blood drain from your brain into the carotid artery in your neck. It has a role in regulating blood pressure.
• Middle ear: Sensory nerve fibers enable you to detect fullness from fluid buildup. You can also feel pain from an ear infection.
• Parotid (saliva) gland: CN IX decreases saliva production when you finish eating.
• Part of the tongue: The glossopharyngeal nerve helps you taste food in the back third of your tongue.
• Stylopharyngeus muscle: A long muscle that runs down part of your throat. CN IX connects to this muscle to lift the voice box (larynx) and nearby throat (pharynx). This makes it possible to swallow.
• Tonsils: Sensory nerve fibers help you sense pain from a sore throat or swelling due to an infection.

What is the anatomy of the glossopharyngeal nerve?

The glossopharyngeal nerve starts in the lower part of your brainstem (medulla oblongata). It passes through many structures in your neck before reaching your pharynx (throat).

Its path includes:

• Exiting your skull through a small opening (jugular foramen).
• Traveling down your neck alongside your jugular vein.
• Going behind the styloid process, a pointy bone in your skull below your ear.
• Curving forward and touching the stylopharyngeus (near your throat).
• Passing under the hyoglossus muscle. This muscle helps you lower your tongue and pull it toward the back of your mouth.

What conditions affect the glossopharyngeal nerve?

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

• Glossopharyngeal neuralgia (GPN): Sneezing, chewing, swallowing and other activities cause episodes of sharp pain in your throat, back of your tongue or middle ear. Fear of future attacks can make eating difficult.
• Glossopharyngeal nerve palsy: An injury or medical condition affects CN IX nerve functioning. The nerve may become partially or fully paralyzed, meaning it can’t do its job. Glossopharyngeal nerve palsy is sometimes a complication of stroke.

What other conditions affect the glossopharyngeal nerve?

Other conditions include:

Tumors and cancer affecting your:

• Brain.
• Lips, tongue and other parts of the oral cavity.
• Middle part of your throat (oropharynx).
• Skull base.
• Tonsils.
• Voice box (larynx).

Complications from medical procedures such as:

• Carotid endarterectomy: This procedure removes fatty buildup from your carotid artery. This vessel supplies blood to your brain. The carotid artery runs in some proximity to the glossopharyngeal nerve.
• Laryngeal mask airway placement: A tube that healthcare providers pass through your mouth and top part of your throat. It delivers oxygen or medications that put you to sleep. The tube may injure sensitive throat tissue, including the glossopharyngeal nerve.
• Tonsillectomy: Some people experience Eagle syndrome after a tonsillectomy. This condition occurs when excess scar tissue stretches nearby cranial nerve fibers. You may experience pain in your throat, neck or ear.

How can I prevent glossopharyngeal nerve issues?

It might not be possible to prevent some causes of CN IX disease. Conditions such as glossopharyngeal neuralgia can occur for no known reason.

If you need a medical procedure to repair an issue near the CN IX, it’s essential to find an experienced surgeon. Doctors who perform a high volume of the type of procedure you need are an ideal choice.

Some conditions, such as cancers affecting your oral cavity and throat, are preventable. Steps you can take to lower your risk include:

• Quitting smoking if you use tobacco.
• Limiting how much and how often you drink alcohol.
• Getting the human papillomavirus (HPV) vaccine.
• Living a healthy lifestyle with a nutritious diet and regular physical activity.

When should I call a healthcare provider about problems with my glossopharyngeal nerve?

Call your healthcare provider if you experience:

• Difficulty swallowing (dysphagia).
• Discomfort or inability to open your mouth.
• Dry mouth.
• Reduced sensation in the back of your mouth.
• Weakened or missing gag reflex.

A note from Cleveland Clinic

The glossopharyngeal nerve (CN IX) supplies organs, muscles and other structures in your mouth and throat. It helps you taste food and sense pain in your throat. CN IX can become damaged due to cancer, complications from medical procedures and more. You can lower your risk by living a healthy lifestyle and seeking surgical care from experienced doctors.