hello everyone this is dr o and here we are moving into the maxillary artery and specifically we're
going to talk about the three divisions of it and branches of the first two divisions
so let's take a look at this image we see that the external carotid artery is heading up here
in the neck deep in the parotid gland where it then bifurcates into its two terminal branches
one cut here is a superficial temporal artery and then the other is the maxillary artery so
the maxillary artery has quite a few branches so we break it down into three specific parts
the first part or the mandibular part passes behind or deep to the neck of the mandible
which is lateral to the lateral pterygoid muscle which is our boundary between the three parts
the next part is the second or the pterygoid part we find that this is either superficial
or deep to the lateral pterygoid muscle and a lot of our illustrations are seeing it
superficial but it's almost half and half where we see it going superficial or deep
then as we go medial or anterior to the lateral pterygoid muscle we get to the third part or
the targo palatine part and its branches for the most part will be within the targo palatine fossa
one thing about the three parts that is distinctive is that the first and the third parts
all of the branches traverse foramina whereas the second part none of them do so we'll talk through
which foramina those are as well we can start this by outlining the lateral pterygoid muscle here
the first part being lateral to lateral pterygoid muscle the second part being again
here superficial but it can also be deep to the lateral pterygoid muscle and third part over here
is where it's entering into the pterygopalatine fossa so we'll see these branches coming off and
this whole portion right here is still that second part it really only becomes that third part as
it's coursing through the target maxillary fissure where it gives off those branches
so let's take it part by part and talk about the branches again we're only going to stick
to the first and the second parts here the third part you'll do in the future when we
when you learn about the pterygopalatine fossa with dr b so with the first part
we can see this is just branching off the external carotid artery before this
lateral pterygoid muscle the first branch we see right here is the deep auricular
artery this will actually pierce through the external acoustic muse and supply the area
the second is typically the anterior tympanic artery it will pass similarly near the area
of the ear and it will enter into the middle ear through the petro tympanic
fissure which is found just on that posterior edge of the mandibular fossa on the temporal bone
next we see our middle meningeal artery so this one will go superiorly in through foramen spinosum
to supply the area we'll also remember that the auriculotemporal nerve will encircle it
so we'll see it kind of passing around that way and that is sort of that relationship we see there
you may see an accessory meningial artery which
will course into the cranial cavity through the foramen ovale
the last branch is the inferior alveolar artery we see this one is the only one
kind of coursing inferiorly toward that mandibular foramen to enter into the mandible
so this will give off a branch this small branch here to the myelohyoid muscle
and then enters into the mandibular foramen where it'll supply the mandibular teeth
and then the chin and the lower lip as it becomes mental artery
our first two here are the deep auricular and anterior tympanic deep auricular tends to be
posterior to that external acoustic meatus which it'll then pierce and enter to supply
the area anterior tympanic a little bit more anteriorly remember it's heading toward that
petro tympanic fissure next we see the meningeal branches so here only the middle meningeal artery
but sometimes you'll also see an accessory meningeal artery and then finally the inferior
alveolar artery that will head into the mandible through the mandibular foramen and the branch to
the mylohyoid muscle will be given off before it and does not enter the mandibular foramen with it
as we move now on to the second part we'll see that these are either superficial or the whole
second part is either superficial or deep to the lateral pterygoid muscle here it is superficial
and we'll remember these from our muscles of mastication and most of the branches of the
pterygoid or the second part are branches to these muscles so what muscles do they supply first we
see here a masseteric artery to the masseter then anterior and posterior deep temporal arteries
that run deep to the temporalis muscle and supply them typically we see that the posterior deep
temporal artery gives off a pterygoid branch we can also see pterygoid branches from the
main maxillary artery as well but these will supply the medial lateral pterygoid muscles
then we see this again sort of the only one coming more inferiorly and down toward
the area of the oral cavity and that is the buccal artery so that will supply the buccinator muscle
but also the area around that buccinator so here we can see the cut esoteric branch as masseter
has been removed we see pterygoid branches here as well as coming off of posterior deep
temporal artery you see the anterior deep temporal artery and then it's quite far actually beyond
the lateral pterygoid in this image but that buccal artery comes off pretty distally toward
the pterygomaxillary fissure but it is still a branch of the second part of the maxillary artery
now the third part here i'm giving you just a preview you're going to have a whole good amount
of time with the pterygopalatine fossa and the branches within it of the artery and the maxillary
nerve but i just wanted to complete the visual here so you have the named branches as they are
these named branches are not meant to be learned immediately right now but they're
there if you'd like to look at them we know that the third part then will enter into this
terrible maxillary fissure where it then gives off branches all of these branches will traverse
foramina just like we saw in the first part and through these branches we'll see supply to the
nasal cavity superior oral cavity the floor of the orbit and the maxillary sinus again
more to come on this just getting you ready to see it in the future
all right so we have a question now which structure passes through the petro-tympanic
fissure with the anterior tympanic artery is it the accessory meningeal artery the chordae
tympani the lesser petrosal nerve or the middle meningeal artery so pause and choose your answer
so when you're ready the correct answer here is b the chorda tympani now the quarter tympani will
exit the temporal bone through this petro-tympanic fissure to then enter into the infra-temporal
fossa whereas the anterior tympanic artery will branch off of the first part of maxillary artery
in the infra-temporal fossa and then enter into the middle ear or the part of the temporal bone
through that petro-tympanic fissure so they kind of are heading in different directions but
both coursing through that same space so what foramina or foramen are we thinking about for
accessory meningeal artery that is foramen ovale now what about lesser petrosal nerve
same thing foramin ovale our last one here
is middle meningeal artery where does that course through
and that will course through the foramen spinosum
great so hopefully this all makes sense to you i hope that this has been helpful here are my
sources thank you so much for your attention and i will talk to you in the next video