3rd, 4th and yeah. So these are the main nerves.
What are the things, we have been discussed are V2 and V3.
So that’s the second and third branches of trigeminal
nerve. So V1 which is the ophthalmic branch,
I said comes out of the superior orbital
fissure. V2 which is called the maxillary
division of trigeminal, comes out through --
Foramen rotundum, very good. V3 is --
Ovale. Ovale, foramen ovale. What are
the other important
structures in foramen ovale, coming out through
the foramen ovale? It has a mnemonic.
Accessory meningeal artery. Accessory meningeal artery, okay.
What is “O” for? Otic ganglion.
V3, so that this
is your mandibular division of trigeminal
nerve, accessory meningeal artery, lesser
petrosal nerve and emissary veins.
What’s the “A” again, sorry?
Accessory meningeal artery. “L” is for
lesser petrosal nerve. Where does the lesser
petrosal nerve come from? Emissary veins?
Yeah. Lesser petrosal nerve is a branch of
glossopharyngeal, and lesser petrosal nerve
is responsible for parasympathetic fibers
to the parotid gland and clinical significance
is even though you have facial nerve which
lies in the substance of the parotid gland,
the parasympathetic is coming from glossopharyngeal.
So the secretion of the parotid gland is not
from the facial nerve, it’s coming through
the lesser petrosal nerve, which is a branch
of the glossopharyngeal. Okay, so this is
essentially your cranial nerves
and the foramen they come out through.
In the face you need to remember, sensory
and motor. All the intersensory part of
the face, this one, all these are by V1,
V2, or V3. Now all muscles of facial expression
are by facial nerve. Muscles of mastication,
chewing are by mandibular division of
trigeminal nerve. So in other words your superior
orbital fissure, the ophthalmic division,
that’s mostly sensory. The next one is maxillary,
that is mostly sensory. And third one is mandibular.
Mandibular is sensory as well as motor.
The motor component is the muscles of mastication?
What are the muscles of mastication? Temporalis?
Buccinator is not.
Masseter, medial pterygoid and lateral pterygoid.
These are the four muscles of mastication.
They’re all supplied by mandibular division
of trigeminal. So if I go back to recreate
this part again, the whole of the face, sensory
is by trigeminal, lateral medial pterygoid.
The muscles of facial expression
is by facial, and muscles of mastication is
by mandibular division of trigeminal.
The maxillary division of the trigeminal,
can you think of anything, any branches? Any
names? I’m only asking the big, the important
ones, you know. For example, if you are saying
this part of the face is supplied by maxillary
division of trigeminal, fine, but then you
need to know a little bit more, couple of names.
Zygomaticotemporal and zygomaticofacial,
they are all coming from the maxillary division.
Then remember I told
you that there is supraorbital nerve and the supratrochlear,
likewise you have an infraorbital nerve, that’s
also from the maxillary division.
Zygomatic what? Sorry. Zygomaticotemporal, zygomaticofacial.
Mandibular division of trigeminal, that’s
quite important for part A. Kindly name
some nerves or divisions. What does the mandibular
division of trigeminal nerve do? It comes
through the foramen ovale and then what happens?
What does it supply?
Yes one of it is alveolar. Anything else,
it’s easy you remember if you classify.
It divides into an anterior division and a
posterior division. Now clearly
I haven’t gone through all the names
of the other nerves because they are not that
important, but this is important. That’s
why I’m just going through the anterior
and the posterior division.
I said V3 is a mixed nerve. It has got sensory
component and motor component and supplies
the muscles of mastication. So before it divides
into this, a branch comes off, here, which
supplies the medial pterygoid. Then
there’s also something called a meningeal
branch of mandibular nerve, which also is
sensory going to the meninges. From your anterior
division, you have the other muscles of mastication,
temporalis, lateral pterygoid and masseter.
So temporalis, lateral pterygoid, masseter.
These are all coming
from the anterior division of mandibular division
of trigeminal nerve. So this anterior
division as it essentially supplies the muscles
of masticatio,n along with your medial pterygoid
which is coming off there. Posterior division,
the mnemonic to remember is MAIL, M-A-I-L,
Can you think of any names here?
Lingual, yeah. So that’s lingual.
So basically if you track it back, lingual
is supplied by the posterior division of the
mandibular division of trigeminal. So that’s
lingual. “I” is for inferior alveolar, you said inferior alveolar.
Inferior alveolar nerve is a nerve which
enters the mandibular canal, here. So when
the dentist is plucking your tooth, that’s
inferior alveolar nerve. It comes out through
the mental foramen, here, mental foramen
and forms the mental nerve. So that’s
the continuation of inferior alveolar.
That’s sensory, this is also sensory. "A" is for auriculotemporal
nerve. That’s the one which supplies sensation
to the ear, auriculotemporal. Here on this
side of the face. And "M" is for nerve
to mylohyoid. So that’s the mnemonic, MAIL.
This is a little bit you need to remember.
This always comes up in some form in your
exam, which nerve is coming out from which
division. And so what the posterior branch
is it then? That’s only sensory, right?
Apart from nerve to mylohyoid, that’s motor.
So nerve to mylohyoid, auriculotemporal,
inferior alveolar, lingual. So that’s
your posterior division and anterior division.
So that brings us to the parotid gland.