This is a tutorial on the vascular supply to the heart.
I'm first going to talk a bit about the arterial supply and then I'll talk about the venous
drainage of the heart.
So like the rest of the body, the heart needs oxygenated blood to function.
So blood that's received from the lungs into the left side of the heart is pumped out of
the aorta and the aorta has some branches which supply the heart.
So at the base of the aorta just after the aortic valves, you've got two branches which
come off the right and left coronary arteries.
So here you can see the right branch coming from the base of the aorta and the left branch
which is slightly hidden under the pulmonary trunk.
You've got left coronary artery coming off the base of the aorta.
The right aortic sinus gives rise to the right coronary artery and the left aortic sinus
gives rise to the left coronary artery.
So you've got these two main branches coming from the base of the aorta, the right and
left coronary arteries.
They've got various branches which I'm now going to talk about.
So also on the heart, you've got grooves.
You've got grooves between the atrium and the ventricles and you've got grooves between
the ventricles.
Between the atrium and the ventricles, you've got a groove called the coronary sulcus.
So in anatomy, in reference to any groove, you'll hear the word 'sulcus'.
So in the brain, the grooves are called 'sulci' (plural) or 'sulcus' (singular) and on the
heart, the same thing apply.
So you've got grooves which are called sulci.
So the coronary sulcus runs between the atrium and the ventricles and the coronary arteries
run in this coronary sulcus.
Between the ventricles, you've got an interventricular groove.
So an interventricular sulcus.
This groove separates the right and left ventricle and some major vessels run down this groove.
So just following the right coronary artery around its course, it winds around along the
coronary sulcus to the back of the heart and it gives off two main branches.
You can see this branch on the right margin of the heart coming off the right coronary
artery.
This is called the right marginal branch.
That's the first branch.
And as we follow the right coronary artery right to the back, you can see this groove
running between the atrium and the ventricles separating the atrium from the ventricle,
it runs right around the heart.
And then you can see this branch here.
This is the posterior interventricular sulcus.
The one I showed you on the front is the anterior interventricular sulcus.
So the artery that branches from the right coronary artery and runs down the posterior
interventricular groove is the posterior interventricular artery, which is also known as the posterior
descending artery.
So you've got two branches of the right coronary artery, you've got the right marginal artery
and you've got the posterior interventricular artery or the posterior descending artery.
This is the right coronary artery you can see here in the coronary sulcus.
So the left coronary artery arises from the left aortic sinus at the base of the aorta.
Looking directly at the heart, you can't actually see this branch.
It's hidden underneath the pulmonary trunk.
So again, this artery has a few branches.
The first branch which you can see running down the anterior interventricular sulcus
is the anterior interventricular artery, otherwise known as the left anterior descending artery.
So that's the first branch of the left coronary artery.
This thing here is the right atrial appendage.
I'll just remove that so we can have a good look at the arteries.
This is the left coronary artery giving off the anterior interventricular artery as its
first branch.
And then it winds around all the way to the back just like the right coronary artery.
This branch which winds all the way around is known as the circumflex artery.
This gives off a branch here.
So like we've got this artery coming from the right coronary artery lying on the right
margin of the heart called the right marginal branch or artery, we've got the artery on
the left margin.
It's the left marginal branch.
This comes off the circumflex artery.
So the circumflex artery winds all the way to the back to the base of the heart and extends
down.
You can see in this model, the circumflex artery extends very far down.
There is anatomical variation between people.
Sometimes, the posterior interventricular artery which usually arises from the right
coronary artery, it can arise at the circumflex artery of the left coronary artery.
This is known as coronary dominance.
Someone whose posterior interventricular artery arises from the circumflex artery, they'll
be left dominant, whereas if the posterior interventricular artery rises from the right
coronary artery, then they'll be called right dominant.
In the majority of people, the posterior interventricular artery arises in the right side.
But in some patients, the posterior interventricular...