Glossopharyngeal Nerve

The glossopharyngeal (GLOSS-so-fer-INJEE-ul) 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 of your brainstem.

The glossopharyngeal nerve ends deep inside your neck, near the back of your throat. It’s one of the few nerves in your body with three types of fibers:

• 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

What is the function of the glossopharyngeal nerve?

The glossopharyngeal nerve supports muscles, organs and body processes near your throat, including your:

• Carotid sinus: This hollow area helps blood drain from your brain into the carotid artery in your neck. This helps regulate your blood pressure.
• Middle ear: Sensory nerve fibers let you feel fullness from fluid buildup in your ears. It also lets you feel ear pain from an ear infection.
• Parotid (salivary) glands: CN IX decreases spit (saliva) production when you finish eating.
• Stylopharyngeus muscle: This long muscle runs down part of your throat. CN IX connects to this muscle to lift your voice box (larynx) and pharynx. This lets you swallow safely.
• Tongue: The glossopharyngeal nerve helps you taste food in the back third of your tongue.
• Tonsils: Sensory nerve fibers allow you to feel pain if you have a sore throat or swelling from an infection.

Where is the glossopharyngeal nerve located?

CN IX starts at the lower part of your brainstem. It runs through your neck before reaching your throat. It follows this path:

• Exits your skull through a small opening (jugular foramen)
• Travels down your neck alongside your jugular vein
• Goes behind the styloid process (a pointy bone in your skull below your ear)
• Curves forward and touches the stylopharyngeus (a muscle near your throat)
• Passes under the hyoglossus muscle near your tongue

What happens if the glossopharyngeal nerve is damaged?

If something damages cranial nerve 9, it might not work correctly. This can affect any of its functions. You might experience:

• Glossopharyngeal nerve paralysis (palsy): Injuries and health conditions can partially or fully paralyze CN IX, meaning it can’t do its job. Paralysis may be a complication after a stroke or a side effect from head and neck surgery. Tumors in your head and neck can lead to it, as well.
• Glossopharyngeal neuralgia (GPN): When something irritates your nerve, you might develop glossopharyngeal neuralgia. Sneezing, chewing and swallowing may make you feel sharp pain in your throat, the back of your tongue or your middle ear. Fear of future attacks can make eating feel scary or hard.

Symptoms that something isn’t working right

Visit a healthcare provider if you have any of the following symptoms:

• Discomfort or inability to open your mouth
• Dry mouth
• Pain in your ears, mouth or throat
• Reduced or no feeling in the back of your mouth
• Trouble swallowing
• Weakened or missing gag reflex

Glossopharyngeal nerve testing

A healthcare provider might test your glossopharyngeal nerve to help diagnose issues or injuries. Your provider will ask you to open your mouth and stick out your tongue (the classic “say ahhh” position).

They might gently poke the back of your throat with a tongue depressor. This can help them trigger your natural gag reflex. Not having a gag reflex can be a sign your CN IX isn’t working properly.