External Carotid Artery

Author: Dr Peter de Souza
Last modified: 17 December 2020


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.


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.

If I just rotate the model around, we can take a look at the external carotid artery.  I just removed the veins of the head and neck. We're just looking at the arterial system.  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.  We’ve got the external carotid and internal carotid.  This pin shows the internal carotid.


The carotid system supplies all the structures in the head and neck.  The internal carotid artery doesn't have any branches in the neck, but the external carotid has eight branches.


You’ve got anterior branches, posterior branches, terminal branches and you've got one medial branch.  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'.  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.


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.


Just above the superior thyroid, we've got the second branch, which is the ascending pharyngeal artery. You can see it here.  As you can see, this branch comes medially off the external carotid artery – and kind of posteriorly.


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, I’ll just draw it on for diagrammatic purposes.  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, 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.


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.  Again, this one isn't shown, I’ll just draw it on for diagrammatic purposes. It's not anatomically accurate.


You’ve got this occipital artery here, which comes off and its branches extends to the posterior side of the scalp.  That comes off the posterior aspect of the external carotid about the same level as the facial artery.


Again, coming off the posterior surface of the external carotid artery, we've got the next branch which is the posterior auricular artery.  You can see this artery here, which is pinned and it runs behind the ear. It gives rise to the name 'auricular'.  'Posterior auricular means 'behind the ear'.


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.


If we start off with the lowest branch, the superior thyroid, the thyroid gland is an anterior structure.  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.  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.  Those are the six anterior, posterior and the medial branches.


The two terminal branches are the maxillary artery and the superficial temporal artery.  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.  It runs right up here. And then it branches into anterior and posterior branches.


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.


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.


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.


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.