External Carotid Branches – 3D Anatomy Tutorial


This is a tutorial on the branches of the
external carotid artery. It’s a very brief tutorial just to introduce you to the branches
and to help you to remember where they come off the external carotid artery. So we’re looking here at an anterior view.
We’ve got the vessels of the head and neck shown on the skeleton. You can see this pin
here shows the common carotid, the right common carotid. Just lateral to that, you’ve got
the right internal jugular vein. So if I just rotate the model around, we can
take a look at the external carotid artery. So I just removed the veins of the head and
neck. We’re just looking at the arterial system. So here we’ve got the common carotid artery
which is shown by this pin here. And then the common carotid splits into an external
and internal branch. So we’ve got the external carotid and internal carotid. So this pin
shows the internal carotid. So the carotid system supplies all the structures
in the head and neck. So the internal carotid artery doesn’t have any branches in the neck,
but the external carotid has eight branches. So you’ve got anterior branches, posterior
branches, terminal branches and you’ve got one medial branch. So we’ll take a look at
these various branches. As with many things in anatomy, there’s a
nice little mnemonic for remembering the branches of the external carotid. The one I use is
‘some ancient lovers find old positions more stimulating’. So it’s quite an easy one to
remember, quite a nice memorable mnemonic. Those branches are the superior thyroid, the
ascending pharyngeal, the lingual, the facial, the occipital, the posterior auricular and
then you’ve got the two terminal branches, the maxillary and the superficial temporal
arteries. So the first artery that comes off just after
the bifurcation of the common carotid is the superior thyroid artery. It’s this artery
pinned here. If we rotate it around, you can see how it descends and it actually descends
onto the superior pole of the thyroid gland. So just above the superior thyroid, we’ve
got the second branch, which is the ascending pharyngeal artery. You can see it here. So
as you can see, this branch comes medially off the external carotid artery — and kind
of posteriorly. So coming off anteriorly off the external
carotid artery, just above the superior thyroid artery is an artery called the lingual artery.
It’s not shown on this model, so I’ll just draw it on for diagrammatic purposes. So it
comes off around here. This is the lingual artery. Then the next artery coming off anteriorly
from the external carotid is the facial artery. In older texts, you might see this referred
to as the external maxillary artery, but it’s now referred to as the facial artery. You can see it’s coarse here, so it’s kind
of windy. And then it comes around over the edge of the mandible. It comes over the edge
of the mandible and anteriorly over the masseter muscle. And where it comes over the edge of
the mandible here, you can palpate it. You can feel your pulse if you put your finger
near to the angle of the mandible. You can feel the pulsation of the facial artery. So coming off just behind or roughly at the
same level of the facial artery from the posterior aspect of the external carotid, you’ve got
the next artery which is the occipital artery. So again, this one isn’t shown, so I’ll just
draw it on for diagrammatic purposes. It’s not anatomically accurate. So you’ve got this occipital artery here,
which comes off and its branches extends to the posterior side of the scalp. So that comes
off the posterior aspect of the external carotid about the same level as the facial artery. So again, coming off the posterior surface
of the external carotid artery, we’ve got the next branch which is the posterior auricular
artery. So you can see this artery here, which is pinned and it runs behind the ear. It gives
rise to the name ‘auricular’. So ‘posterior auricular means ‘behind the ear’. So the next two arteries are the terminal
branches of the external carotid. We’ve looked at six branches so far. And the way to remember
whether they come off anteriorly or posteriorly is quite simple. The way I do it is just thinking
of the structures. Think of the names and think of whether the structures that their
names relate to are anteriorly or posteriorly. So if we start off with the lowest branch,
the superior thyroid, the thyroid gland is an anterior structure. So the superior thyroid
artery is an anterior branch. Next up, we’ve got the lingual artery. Lingual refers to
tongue. The tongue is an anterior structure. So the lingual artery is an anterior branch. And then we’ve got the facial artery. The
face is anterior, so the facial artery is an anterior branch. And then posteriorly,
we’ve got the occipital artery. The occipital bone is the back of your skull. So the occipital
branch is a posterior branch. And then we’ve got the posterior auricular
branch. In the name, it says ‘posterior’, posterior auricular, behind the ear. That
is a posterior part of the body so it’s a posterior branch. And then you’ve got the
ascending pharyngeal, which is a medial branch. It’s kind of deep and medial and a little
bit posterior. So those are the six anterior, posterior and the medial branches. So the two terminal branches are the maxillary
artery and the superficial temporal artery. So the maxillary artery can be seen here.
This pin is stuck into the maxillary artery. The superficial temporal artery runs up the
superficially on the scalp. So it runs right up here. And then it branches into anterior
and posterior branches. So remember I said that the facial artery
is sometimes referred to as the external maxillary. The maxillary artery is referred to as the
internal maxillary in older textbooks. So if I just rotate the model around posteriorly,
we can see the maxillary artery running behind the neck of the mandible here. And if I rotate
it round again to the lateral view, you can see it passing medially to the neck of the
mandible and then it passes into the infratemporal fossa and ultimately, into the pterygopalatine
fossa. So the superficial temporal artery, you can
see is pinned here. This artery also runs posterior to the neck of the mandible and
then it runs anterior to the ear and then it runs up into the scalp where it separates
into its posterior and anterior divisions. So that was just a very quick run through
of the branches of the external carotid artery. I just wanted to give you a way to remember
those branches and to show you what order they came off the external carotid artery.