When we look at the chambers and great vessels
of the heart, we?ll begin here with the
chambers themselves. But the heart is going
to have two upper chambers ? and we?ve
referred to those as atria. And the heart
will have two more muscular chambers, which
are the main pumping chambers of the heart,
which are called the ventricles.
If we take a look at what we have here in
this image, please take a look very closely
at the right atrium in through here. We see
it very, very well. This rounded portion of
the right atrium is called the auricle, or
right auricle, of the right atrium. And then,
over here, we have the auricle of the left
atrium. We do not see in this view very much
of the left atrium and we?ll have another
opportunity here to see it in greater detail.
Please note, please do not interchange atrium with an auricle.
An auricle is a part of an atrium.
The main muscular chambers are shown down
in through here. This would be your right
ventricle. And then if you look over here,
you see a portion of the left ventricle.
Great vessels are going to be attached to
the chambers of the heart. When we do an accounting
of the great vessels, we?re going to come
up with a total of 8. So you?ll want to
keep in mind how many of these are veins and
how many of these are arteries. You?ll also
want to keep in mind where the veins empty
and what chambers issue the arteries.
So if we take a look, let?s focus on the
veins first. There are six veins and only
two arteries. And veins are going to empty
into the atria.
If we look at the right atrium, we see in
this view one of those veins. This is the
superior vena cava. If we go to the view down
and to the right, you will then be able to
see not only the superior vena cava, again
emptying into the right atrium, but here you
can appreciate the inferior vena cava emptying
into the right atrium.
You may be aware already that most of the
inferior vena cava resides within the abdominal
cavity and then it will pass through the caval
hiatus in the diaphragm. And then there to
meet it once it enters the thoracic cavity
is the right atrium. So the inferior vena
cava is a very short vessel within the thoracic
cavity. So that takes care of two of our six veins.
The other four veins are going to empty into
the left atrium. And we see those four veins
here, here, here and here. And two of the
veins are coming from the right lung and the
other two pulmonary veins are coming from
the left lung. So here are your right superior,
right inferior pulmonary veins. And then here
are the fellow veins from the left: left superior
pulmonary and then your left inferior pulmonary.
Arteries are going to receive blood ejected
by the ventricles. The right ventricle
will pump blood into the pulmonary trunk, which
we see here, and then your left ventricle
will pump blood into the aorta and specifically
the ascending aorta.
Now let?s take a look at the surface anatomy
of the heart. And we?re going to begin with
the sulci. These are very important landmarks
in that they?ll separate the atria from
the lower chambers, the ventricles. And then
other sulci will separate the right ventricle
from the left ventricle. And so a surgeon
can look very, very quickly at one of the
sulci to determine whether or not he?s looking
at the right ventricle or if he is looking
at the left ventricle.
But if we take a look here, let?s look at
a sulcus. Here we see it in the anterior view.
This sulcus will continue to the diaphragmatic
aspect of the heart and will separate the
atria from the ventricles. This sulcus forms
a crown around the heart, hence one of the
names is the coronary sulcus. And a more descriptive
terminology anatomically is that, since it?s
between the atria and the ventricles, we can
also refer to it as the atrioventricular sulcus.
Another sulcus is running right along here.
And this is referred to as the anterior interventricular
sulcus. And it will then continue inferiorly,
wrap around toward the diaphragmatic aspect
of the heart, as we see here, and be seen
on its diaphragmatic surface.
In the anterior view, this is the anterior
interventricular sulcus. In the diaphragmatic
view, it is referred to as the posterior interventricular
All these sulci contain variable amounts of
fat. So you see some fat here in the coronary
sulcus. You see some fat also here in the
anterior interventricular sulcus. A little
bit more sparse here in the posterior diaphragmatic
view. And you?ll also find the major coronary vessels.
So if we take a quick look here back in the
coronary sulcus, the coronary artery that?s
running through the sulcus in this view is
your right coronary. And then you can see
one of the branches here in the anterior interventricular
sulcus from the left coronary. And you can
see in the posterior diaphragmatic view, you
can also see some of the components of your
coronary circulation. And we?ll speak in
greater detail about the coronary circulation shortly.