Glossopharyngeal Nerve Overview in 5 minutes – Human Anatomy | Kenhub


If you’re anything like the rest of us, the
thought of learning all the intricacies of the cranial nerves makes you want to curl
up into a ball and hibernate. Yes, just like this little guy here. There’s a lot to be learned and it’s not all
easy. Hey, we got it and we want to help. That is why, in this video, we’re going to
be talking you through the glossopharyngeal nerve in just five minutes. Yes, really. It’s possible, and it’s time to start learning
quickly and efficiently in a way we like to call the Kenhub style. What we see here is a lateral view of the
brain. When we turn it, we can see these yellow structures
which are called cranial nerves. The glossopharyngeal nerve belongs to a set
of neural structures called then the cranial nerves. Now if we zoom in, we can see the glossopharyngeal
nerve now highlighted in green. It is a bilateral nerve which means you can
find one on each side like we do for the other cranial nerves. The glossopharyngeal nerve is the ninth out
of the twelve cranial nerves and is typically abbreviated as CN Roman numeral four nine,
if you’re feeling fancy, of course. You now see on the screen and image of the
lateral head. I asked this nice lady to use her profile
picture. We will be exploring these structures that
I am overlapping right now just to give you an idea where they are located in your body. Note that this is a schematic view which shows
structures placed slightly different from what they usually are in the body, and we
do that so we can show things a bit more clearly for you guys. We’re good eggs like that. Highlighted here in green, you can see then
the glossopharyngeal nerve in all of its glory. In this video, we’ll be doing an overview
of the anatomy connected to the different functions of the glossopharyngeal nerve. In the following slides, we’ll be showing
you each of the branches of the glossopharyngeal nerve one by one. These will always be highlighted in green
so keep your eyes peeled for any changes that might be happening on the screen. And let’s start with the branches of the glossopharyngeal
nerve that are responsible for general sensation along with the structures that the sensations
are transmitted through. We have the lingual branches of the glossopharyngeal
nerve which are responsible for the sensation of the tongue. Then we have the tonsillar branches of the
glossopharyngeal nerve which are involved in the sensation of your tonsils. Next, we have the pharyngeal branches of the
glossopharyngeal nerve. These are responsible for the afferent innervation
of the pharynx. The tympanic branch of the glossopharyngeal
nerve seen here where the arrow is, is involved in the innervation of the middle ear of the
pharyngotympanic tube. As part of that, in the middle ear, the tympanic
branch ramifies on the tympanic membrane to form the tympanic plexus which happens to
be this structure that you see now highlighted on the screen. Tubal branch also joins the tympanic plexus
bringing with it sensory information from the pharyngotympanic tube which is the tube
that connects the nasopharynx and the middle ear. The final area of general sensation received
by the glossopharyngeal nerve arises from the external ear and is known as the communicating
branch of the vagus nerve. Now, this little guy piggybacks on the auricular
branch of the vagus nerve as you can see in this illustration. Now, let’s take a look at the structures involved
in special sensation. Well, actually, you only need to remember
one and that is taste. The glossopharyngeal nerve is involved with
the sensation of taste via the lingual branches. These nerve branches eventually synapse in
the solitary nucleus. Next up is visceral sensation. The glossopharyngeal nerve receives input
from two structures – the carotid body which transmits information about blood chemistry
and the carotid sinus which monitors blood pressure. Next up are the parasympathetic functions. The parasympathetic function of the glossopharyngeal
nerve supplies secretomotor fibers to the parotid gland and going from the inferior
salivatory nucleus to the tympanic plexus to then the lesser petrosal nerve then the
foramen ovale, the otic ganglion as you can see here, and to the auriculotemporal nerve. Last, but not least, we will look at the somatic
motor function quickly. The glossopharyngeal nerve innervates the
stylopharyngeus muscle with nerves originating from the nucleus ambiguus in the medulla oblongata. And we are done folks. We just covered the glossopharyngeal nerve
in just five minutes. You can pat yourself on the back. You made it. But there is a lot more information to learn
about the glossopharyngeal nerve. On this video, we just went through some of
the most relevant points connected to this cranial nerve. We hoped you enjoyed it and if you’re looking
for more in-depth videos or articles or even atlas sections or quizzes to test your knowledge
on the glossopharyngeal nerve, then be sure to check out our main website at kenhub.com,
and I hope to see you there!