hi let's talk a little bit about the heart so as you may recall the hearts it's within
the mediastinum which is medial to the two lungs this heart you can see the apex of which is left
anterior lateral and the diaphragmatic surface is inferior here and it's in line with the base of
each lung now if we take a look at just a heart we can see the right margin of the heart that
corresponds with the right atrium we can see the left margin of the heart that's corresponding with
the left ventricle and we can see the inferior border of the heart that's associated with both
ventricles but predominantly the right ventricle here's the apex of the heart and if we were to
turn the heart upside down we get a good view of the diaphragmatic surface of the heart along with
that posterior interventricular sulcus now if you recall there are three important sulci for you to
know of the heart there's the coronary sulcus that runs between the atria and the ventricles
there's an anterior interventricular sulcus that's anterior to the interventricular septum the wall
of muscle between the two ventricles and then there's the posterior interventricular sulcus
that is inferior posterior to the interventricular septum all of these sulci represent opportunities
for the vasculature of the heart to move around and on top of the heart unimpeded so we've looked
at some of the superficial aspects of the heart let's take a look at some of the vasculature that
supplies the heart as you may recall the heart is supplied by both the left coronary artery
and the right coronary artery both of these exit from the ascending aorta which you can see here
the right coronary artery typically is going to spawn the SA nodal branch and then descend just
between the ventricle and the auricle of the atria and when it gets to the inferior border
of the heart it's going to give off the right marginal branch it then continues around on
the inferior surface or diaphragmatic surface of the heart still in the coronary sulcus and
it's going to spawn off deeply the AV nodal branch to the AV node and in right dominant
hearts which is what is most typical the inferior interventricular I'm sorry the
posterior interventricular branch the posterior interventricular branch the left coronary artery
when it exits the ascending aorta very quickly divides into the anterior interventricular branch
sometimes called the left anterior descending branch that's going to supply the majority of
the wall of the left ventricle with blood as well as the circumflex branch the circumflex branch
rides down in the coronary sulcus here before usually terminating in what's known as the left
marginal artery but sometimes that circumflex branch can continue on the posterior it's not
on this particular specimen and help give rise to that posterior interventricular branch in
terms of the coronary veins the the picture is much more simple the great cardiac vein arises
in the interventricular septum along with the anterior interventricular branch of the left
coronary artery it then travels in the coronary sulcus around to the inferior or diaphragmatic
surface of the heart where it feeds into the coronary sinus it receives contributions from
the middle cardiac vein that's in the posterior interventricular sulcus and continues on and
receives another contribution from the small cardiac vein which accompanies the right marginal
branch before emptying into the right atrium now there are a few smaller cardiac veins which do
not drain into the coronary sinus and these are called the anterior cardiac veins the anterior
cardiac veins drain the superficial aspect of the wall of the right ventricle and there are
typically three to five of these veins and they're very noticeable because they bridge over the RCA
and they feed directly into the right atrium so we've talked about the superficial anatomy of
the heart we've talked about the coronary arteries and the cardiac veins thank you