From this angle I want to discuss some of the blood vessels that supply the head and
the neck, and also play a role in forming the cerebral arterial circle, or the circle
of Willis.
On this model we can see the left common carotid artery ascending in the neck, and then dividing
to do the internal carotid artery, which will pass through our carotid canal in the temporal
bone, and we can see the external carotid artery, which passes external on the skull
to provide many branches on the head and neck.
One of the main branches that we should be aware of is known as the facial artery.
Here we can see the facial artery passing through the buccal region of the cheek.
Now this model has been broken.
This facial artery should come off of this point of the External carotid artery.
Also if you look a little bit further behind, inside the transverse foramen of cervical
vertebra one two three four five and six, but not C7, we can see the vertebral artery.
The vertebral artery passing through the transverse freeman of those six cervical vertebra and
it will ultimately pass through the foramen magnum where it will join to form the basilar
artery, which takes part in the cerebral arterial circle.
In this video I want to discuss the blood vessels that make up what is known as the
cerebral arterial circle, sometimes known as the circle of Willis.
The circle of Willis is formed by blood vessels that come from the vertebral arteries, and
the internal carotid arteries.
On this model we can see coming up through foramen magnum the vertebral arteries.
And the vertebral arteries will join to form what is called the basilar artery.
One artery which passes along the anterior surface of the pons.
On this model they do not show the posterior inferior cerebellar artery, which would have
come off of the vertebral arteries.
The lower of the arteries off of the basilar artery on this model, is the anterior inferior
cerebellar artery.
Supplies the anterior inferior surface of the cerebellum.
The next blood vessel we see off of this basilar artery is known as the superior cerebellar
artery.
Obviously it will supply the superior surface of the cerebellum.
Then this basilar artery branches to the right and left, it is a little harder to see the
lift here because the red has been chipped away.
These are known as the posterior cerebral arteries.
They will supply blood to the posterior portion of the cerebrum.
I'm going to jump forward for a second.
Coming through the carotid canal in the temporal bone, we can see the internal carotid artery
here and here.
That internal carotid artery will turn and head to the brain where it becomes the middle
cerebral artery.
So you have the posterior cerebral artery and a middle cerebral artery he.
And those two are connected by a branch known as the posterior communicating artery.
You can see the posterior communicating artery here on the left and on the right.
Between the posterior cerebral artery and the middle cerebral artery.
Also off of the middle cerebral artery and we will see the anterior cerebral arteries,
which will supply the anterior portion of our cerebrum.
And between those two anterior cerebral arteries there's a short in the branch called the anterior
communicating artery.
So these are the vessels that we pull together when we talk about the cerebral arterial circle
of Willis.
However the actual circle is only right here in this small area.
The cerebral arterial circle of Willis is comprised of the posterior cerebral arteries,
the posterior communicating arteries, part of the middle cerebral arteries, the anterior
cerebral arteries, and the anterior communicating artery.
Form a circle in this general region.