Glossopharyngeal Nerve Summary
HIDEInteractive Transcript
0:00
Dr. P here summarizing the 9th cranial nerve.
0:04
We learned that there are three real origin components of
0:07
the glossopharyngeal nerve
0:09
at the level of the medulla oblongata.
0:11
We've got the nucleus ambiguus,
0:14
which is just posterior to the mid coronal plane,
0:17
close to the midline.
0:18
We've got the inferior salivary nucleus.
0:21
And although I haven't divided them up
0:23
into sensory and motor this time,
0:25
we've also got a little more lateral to that,
0:27
the nucleus of the solitary tract.
0:31
And these three are going to contribute to both sensory
0:33
and motor components of the glossopharyngeal nerve
0:36
to create the apparent origin of the glossopharyngeal nerve,
0:40
which travels very nicely with its companion,
0:43
the vagus nerve, which I'll draw over in red right here.
0:48
So then, these nerves go out to the side
0:51
and we're going to come off now our drawing tool,
0:53
and we're going to go down.
0:54
And the nerve sits between the carotid artery and the
0:58
jugular vein, traveling inferiorly as we discussed before.
1:01
Now, the branches include tympanic, stylopharyngeal,
1:04
and tonsillar.
1:05
There's a nerve to the carotid sinus branches to the
1:08
posterior third of the tongue which participate in taste.
1:12
And these are known as lingual branches.
1:15
There's also a communicating branch to the vagus nerve.
1:18
It's important when you're taking any board exam that you
1:21
remember the glossopharyngeal provides taste
1:23
to the posterior third of the tongue.
1:26
Taste to the anterior two-thirds of the tongue comes from
1:28
the chorda tympani nerve, from the facial nerve,
1:31
traveling with V3,
1:33
the third division of the trigeminal nerve.
1:35
The glossopharyngeal nerve also contributes in the
1:38
formation of the pharyngeal plexus,
1:41
along with the vagus nerve,
1:42
and has motor supply to some of the constrictor
1:46
muscles and muscles of the pharynx.
1:49
Dr. P out.
Stephen J Pomeranz, MD
Chief Medical Officer, ProScan Imaging. Founder, MRI Online
ProScan Imaging
© 2024 MRI Online. All Rights Reserved.