Cranial nerve · one in each half of the brain
Glossopharyngeal nerve (IX)
Also called Cranial nerve IX, CN IX, Ninth nerve
Tastes the back of your tongue, starts your gag reflex, and checks your blood pressure.
The glossopharyngeal nerve looks after the back of your mouth and throat. It carries taste and touch from the back third of your tongue and feels anything that touches the back of your throat, setting off the gag reflex. It also helps you swallow and tells a big saliva gland to make spit. And it has a hidden job: it senses blood pressure and oxygen in the main artery of your neck.
Where it is
It leaves the side of the medulla, the lowest part of the brainstem, exits the skull through an opening it shares with the vagus and accessory nerves, and runs down to the throat and the back of the tongue.
What it does
Taste at the back
It carries taste and touch from the back third of your tongue.
Gag reflex, sensing side
It feels touch at the back of the throat. If something unexpected lands there, it triggers the gag reflex to protect your airway.
Swallowing
It powers a small throat muscle that lifts the throat when you swallow.
Saliva
It tells the parotid gland, the biggest saliva gland, just in front of your ear, to make saliva.
Blood pressure sensor
Sensors in the big neck artery report blood pressure and oxygen levels through this nerve, so the brain can adjust your heart and breathing.
Think of it as the security guard at the back door of your mouth, checking what comes in and sounding the alarm if something should not go down.
Works with
- Medulla oblongataIts control centers sit in the medulla, next to the centers that handle breathing, heart rate, and swallowing.
- Vagus nerve (X)In the gag reflex it senses the touch and the vagus makes the throat squeeze. They also team up to control blood pressure.
- Facial nerve (VII)The facial nerve covers taste at the front of the tongue, while this nerve covers the back.
- InsulaTaste signals from the back of the tongue end up in taste cortex in and near the insula.
- Accessory nerve (XI)These two leave the skull through the same opening, along with the vagus.
When it goes wrong
How doctors check it
A gentle touch at the back of the throat should cause a gag. This nerve feels the touch and the vagus nerve makes the throat squeeze.
Glossopharyngeal neuralgia
A condition that causes sudden, sharp pain on one side, deep in the throat, tonsils, or base of the tongue, often set off by swallowing, chewing, coughing, or yawning.
Three nerves, one opening
Because it leaves the skull through the same opening as the vagus and accessory nerves, a problem there can affect all three at once, causing trouble swallowing and a hoarse voice.
For learning only, not medical advice. If you have a health concern, talk to a doctor.
Surprising facts
- The famous "tongue map", with sweet at the tip and bitter at the back, is a myth. Every part of the tongue with taste buds can sense all the basic tastes. This nerve simply looks after the taste buds at the back.
- Pressure on the big artery in the side of the neck can slow the heart: this nerve senses the pressure, and the vagus nerve slows the beat. Doctors sometimes use a careful version of this to calm certain racing heart rhythms.
By the numbers
Where the name comes from
From the Greek glossa, "tongue", and pharynx, "throat". It is the tongue-and-throat nerve.
Quick quiz
3 questions. Your answers are saved and come back in your daily review.
Which of these is a job of the glossopharyngeal nerve (IX)?
Show the answer
Taste at the back. It carries taste and touch from the back third of your tongue.
Taste at the back. It carries taste and touch from the back third of your tongue.
The glossopharyngeal nerve (IX) is part of which larger structure?
Show the answer
Cranial nerves. It belongs to the cranial nerves.
Cranial nerves. It belongs to the cranial nerves.
Which part fits this description? "Like the security guard at the back door of your mouth, checking what comes in and sounding the alarm if something should not go down."
Show the answer
Glossopharyngeal nerve (IX). It is the glossopharyngeal nerve (IX). Tastes the back of your tongue, starts your gag reflex, and checks your blood pressure.
Glossopharyngeal nerve (IX). It is the glossopharyngeal nerve (IX). Tastes the back of your tongue, starts your gag reflex, and checks your blood pressure.
These parts now come back in your daily review, just before you would forget them.
Practice it and its neighbors in 3DSources
- Neuroanatomy, Cranial Nerve 9 (Glossopharyngeal), StatPearls, NCBI Bookshelf
- 16.3 The Cranial Nerve Exam, OpenStax, Anatomy and Physiology 2e
- Taste Disorders, National Institute on Deafness and Other Communication Disorders (NIDCD)
Spotted a mistake? Tell us.
Explore the glossopharyngeal nerve (IX) in 3D
Turn it around, zoom inside and see how it connects to the rest of the brain, then test yourself with quick quizzes.
Open it in 3D