alright Ninja Nerds we're going to take a
look here at the heart so if you look
here at the heart this is the anterior
surface of the heart this back here is
the posterior surface of a heart
inferior surface down here this is the
apex of the heart and then up here is
the superior surface or you know we
actually say like that the base is going
to be pointing towards the right
shoulder alright so let's take a look at
the heart we're going to kind of go over
all the structures and anterior surface
here so if you look here you can see
this part right here this little fatty
pouching here this is actually an auricle
and it's on again this is over here this
is the left side and over here this is
the right side so this is the left
auricle and the left auricle is kind of
like a fatty pouch and has some muscle
tissue that also allows for it to kind
of squeeze some of the blood into the
atria in that area right behind this is
going to be the left atrium I will show
you when we take this this piece off
over here we can see the right auricle
all right if you look here this is going
to be the pulmonary trunk that's the
pulmonary trunk its what takes
deoxygenated blood from the right
ventricle to the lungs to get oxygenated
all right so that's why it's actually
going to appear blue because it's going
to be taking again deoxygenated blood
from the right ventricle to the lungs to
get oxygenated so it goes pulmonary
trunk and then it has this branch over
here that we can see this is actually
going to be the specifically the left
pulmonary artery we'll take a look at
the bright pulmonary artery here in a
second if you look here we have a big
big vessel coming out of the heart this
is going to be the aorta so this is the
whole aorta right here this is the
ascending aorta this portion here this
is the aortic arch okay right here and
then you have three vessels that come
off the aortic arch in orders already
this first one here is actually going to
be called the brachiocephalic artery
okay it splits into the specifically the
right subclavian and the right common
carotid the second one here is going to
be called the left common carotid artery
okay and there's one back here all the
way in the back here is going to be the
left subclavian artery and then again
the aortic arch will going on into the
descending
or we actually say first thoracic and
abdominal but we'll see that in other
models all right now let's go ahead and
turn this a little bit  and I
turned it here to the right side this is
this is the right side of heart so this is
the right atrium right here if you look
here we got a nice big vessel right here
that dumps into the right atrium the big
systemic vein this one right here is
called the superior vena cava that's a
superior vena cava this vein right here
and this vein right here they actually
merged together one comes from
the right side one comes from the left
side so this is the right
brachiocephalic this one right here this
one over here is the left
brachiocephalic vein okay so we got left
brachiocephalic vein right
brachiocephalic vein come together and
make the superior vena cava which dumps
into the right atrium there you can see
this little veins that kind of like
nothing off the back here it's actually
going to be feeding into the superior
vena cava this is called the azygos vein
well we'll take a better look at it when
I keep turning it around so we can look
at the posterior portion of the heart
some of those vessels let me keep
turning it around little bit more
alright guys so if you see here we can
still see a piece of that aorta again
that's going to be the descending order
it's going to go down because the
thoracic aorta down here then you can
actually see nice nice view here of the
pulmonary artery this one is the right
pulmonary artery over here and this one
over here is the left pulmonary artery
so again those are deoxygenated vessels
remember that they're taking blood to
the lungs to pick up oxygen that's why
they appear to be blue so most people be
like all these are the pulmonary veins
no they are the pulmonary arteries
arteries by definition take blood away
from the heart vein take blood back to
the heart and then the veins that come
back from the lungs are going to be
oxygenated that's why these ones are the
pulmonary veins and they're red so don't
get that confused again these ones over
here are the pulmonary veins this would
be the left pulmonary veins left
pulmonary artery this one right there
right a pulmonary artery over here is
the right pulmonary artery and down here
going to be the right pulmonary veins
all right again you can actually see
that vein that I was showing you before
this one right there is be azygos
vein that one right there and it
actually comes up all the way from your
actual  common iliacs,  it can bring
blood all the way up and bypass the
inferior vena cava we'll talk about
that with its relationship pregnancy
and one of the other models again azygos
vein there and then we're taking a
look at the post here portion of the
heart now we're going to do is we're
going to flip it back over and we're
going to take a look at some of the
vessels with the coronary circuit
and now  here again back on the
anterior aspect of the heart again we're
going to take a look at at the coronary
circuit now the coronary circuit i'm
going to show you that after when i take
this piece off you're going to be able
to see two arteries coming off of the
aorta and they're the first ones to come
off of the ascending aorta actually it's
the right coronary artery and the left
coronary artery we have a video in the
physiology where you can actually see
the circuit in more detail also but this
is going to are going to go over the
anatomy here so if we look you can see
this artery right here is going to be
coming all the way down here and this
one is actually going to be the anterior
interventricular artery right there
anterior interventricular artery but
they also can call it the left anterior
descending artery okay this is one of
the most common areas about forty
percent of the myocardial infarctions
actually occur within this artery well
due to the blockage of this artery okay
because it supplies a good chunk of
muscle supplies the anterior walls of
the ventricles right on the left and the
right and it supplies the actual
anterior wall of the
interventricular septum another branch
so again this is actually going to be
this artery right here comes off of a
specific coronary artery and that is the
left coronary artery so remember left
coronary artery gives way to two
arteries this one right here anterior interventricular
again or you can also
call it left anterior descending and the
other one is going to come off of the
side over here and that's going to be
this one right here number 11 that's
going to be called the circumflex artery
so the circumflex artery actually kind
of wraps right around this auricle you
can supply a little bit of the atrial
muscular wall and it can supply some of
the lateral walls of this left ventricle
over here okay not too common of an area
for the myocardial infarctions or blocks
clots to form than that one alright now
we're going to do is we're going to turn
it back over here because now I want to
cover the veins in this area so if we
come back over here what happens is the
anterior interventricular artery or the
last left anterior descending takes
blood to the myocardium
drops off the oxygen after drops off the
oxygen it picks up the co2 and it's
going to have to come back through a vein
well the vein that it comes back through
is this one running right next to it
that blue vein there running right up
this guy is called the great cardiac
vein the great cardiac vein which is
going to be number 14 here okay so
number 10 is the left anterior
descending or again anterior interventricular
and 14 is going to be the
great cardiac vein all right and these
kind of both run down what's called the
anterior interventricular sulcus which
is like a fat filled groove primarily
the anterior ventricular artery runs out
Down this little fat filled groove right
there which is called the anterior interventricular
sulcus alright so again
great cardiac vein now if I turn it over
here go back to the circumflex artery
well what vein over here drains it
there's a vein right next to him right
there okay that's called the posterior
vein of the left ventricle so that
drains the myocardium and brings the
blood back right that's that one now
what we're going to do is we're going to
take a look at the branches off of the
right coronary artery so if we look over
here this right here is the right
coronary artery right here to running
all the way down 155 it's running all
the way down what's called this coronary
sulcus so it's running down this fat
filled groove here called the coronary
sulcus then it has a branch that comes
off of it right so this is one branch
right here and this is actually going to
be number eight I turn a little bit
better you might be able to see it this
is number eight right here that's the
marginal artery the marginal artery
supplies the lateral walls of the right
ventricle right and then if you look
here it goes in delivers oxygen to the
myocardium after delivers the oxygen to
the myocardium picks up the co2 and it's
going to have to come back through the
vein will add vein does it come back
through it comes back through this vein
number 12 and that's going to be called
the small cardiac vein okay these ones
they don't talk too much about it but
this one's called this just called the
anterior cardiac veins that's the
anterior cardiac vein and then this one
right here which is kind of a little bit
more important it's the small cardiac vein
all right now what happens is the right
coronary artery continues to track its
way down through this coronary sulcus
and as it tracks its way through the
coronary sulcus it comes around
the heart and what we're going to do is
we're going to take this heart off so we
can see a better view of another artery
branch all right guys let's track that
right coronary artery so we're tracking
that right coronary artery back here to
the posterior side of the heart and as
we come over here it gives off this
branch down here look at this guy all
the way down here all this right here
even a little bit of this part over here
this is all called the posterior
interventricular artery so again all
this puppy right here and even a little
bit of e branches off here so that's the
posterior interventricular artery and it
runs through a fat filled groove which
is called the posterior interventricular
sulcus so now this is delivering oxygen
rich blood and it takes it to the
myocardium right so when it takes it to
the myocardium it drops off the oxygen
picks up the co2 in the waste product
and it's going to come off of that
capillary bed through a vein well guess
what vein is going to be running through
the one right adjacent to it this one
right here 13 all this puppy right here
this is all called the middle cardiac
vein all this right here is the middle
cardiac vein all right so little cardiac
vein here's another piece of it all that
is the middle cardiac vein now all the
middle cardiac vein it will also dump
when it combines with the small cardiac
vein the great cardiac vein the
posterior vein of the left ventricle all
of those guys will combine and dump that
blood into this big big vein up here
called the coronary sinus and then the
coronary sinus dumps it into this cavity
in here or this chamber called the right
atrium alright and this would be
inferior vena cavas this big gaping hole
right there alright next thing I want to
show you guys something really cool if I
turn the heart a little bit over here
you can kind of see the posterior
interventricular artery kind of confuses or
Anastamoses with the marginal artery
over here that we already saw so here's
our marginal artery and it forms an
anastomosis a collateral alternative
channel for the blood to flow through
with the posterior interventricular
artery so that's a cool arterial
anastomosis alright so if we look here
we got the circumflex artery right this
was the one of the branches off of the
left coronary artery well guess what it
can anasta Mose with the posterior
interventricular artery so there's an
anastomosis between the circumflex
artery number 11 over here and the
posterior interventricular
so that's a pretty anastomosis
now it's go to the anterior side to see
some more anastomosis but look over
here this artery coming off another
branch of the left coronary artery is
the anterior interventricular
artery and it actually comes off and
look there is another anastomosis with
the circumflex artery so this is an
anastomosis between the anterior and
interventricular artery and the circumflex
artery alright but then if we turn it
over just a little bit more again we
have the marginal artery over here and
the marginal arteries look it anastemosis
here with the anterior
interventricular arteries so we have all
different types of astemoses here and
it's just really really important to
know that arterial  Anastomoses provide
alternative or collateral routes for the
blood to flow to in case there might be
some type of thrombus or embolus or
clot of some form it just ensures that
enough oxygen will get to the tissue
alright guys so now what I'm going to do
is I'm going to take this and this part
off here so we can kind of look inside
of the heart alright let's take a deeper
look inside of the heart so if you look
here we have the two top chambers this
chamber right here is going to be called
the right atrium this chamber right here
is going to be called the left atrium
alright so together we call them atria
right then if you look here we have a
valve a nice little valve right here
that separates the right atrium from the
right ventricle this valve right here is
called the tricuspid valve okay and if
you see these little cords coming down
from that valve the leaflets this is
going to be called the chordae tendineae
the little collagen cords all right and
they're going to be anchored down by
these muscles right here they're
anchored down by these muscles which are
called the papillary muscle you can see
that one right there 154 and you can see
the other one over here really really
well which is angering down that chordae
tendineae nice all right let's turn it
over a little bit more so we can see a
couple other structures inside the right
atrium alright so now that I got a
better view here let's take a look you
can actually kind of see a little bit of
scar tissue if you remember from the
fetal circulation video there was a hole
here and that hole was called the
foramen ovale right and that's what
allows for blood to get shunted from the
right atrium all into the left atrium to
bypass the pulmonary circuit well after
the fetus is born this turns into a scar
tissue right here
and it's now called the fossa ovalis
again it's called the fossa ovalis it's
just a scar tissue right there okay and
then if you look here that number 26
that little black hole right there
that's the opening of the coronary sinus
so if you remember the coronary sinus
the one who collected the blood from the
middle cardiac vein, great cardiac vein,
small cardiac vein Posterior vein of the
left ventricle and anterior cardiac veins it
that that's the part that it's emptying
into the right atrium alright and again
we already said tricuspid valve here we
already said the chordae tendineae there
and we already said the papillary
muscles and then again this whole
chamber down here is the right ventricle
all right so now let's go ahead and take
a look here if you remember the
ventricles the ventricles re you're pumping
chambers so they're the ones that are
designed to contract and pump blood out
of heart so what they do is they pump
blood up through this pulmonary
semilunar valve okay this
little crescent-shaped looks likes it
looks like half a moon right so that's
again that your pulmonary semilunar
valve right there and remember we're going to
talk about this it goes up into the
pulmonary trunk now you're into the
pulmonary arteries right and if you look
right here i'm going to turn a little
bit more go for you guys you can see
this little structure right there that
little white structure there that is
called the ligamentum arteriosum oh if
you remember when we did fetal
circulation it's called the ductus
arteriosus and it's a shunt that shunts
the blood from the pulmonary trunk into
the aorta to bypass the blood going to
the lungs so whenever the baby
is born it turns into a ligament to
close that hole off right and again
becomes the ligamentum arteriosum
alright so now let's go ahead and turn
it over more so we can see the left
atrium and the left ventricle over here
so these look you got that big hole
right there that's the opening of the
right pulmonary veins so the blood
that's coming from the right lung is
actually empty into the left atrium over
there and that hole and then if you look
over here we got these two little tiny
holes over here is coming from these
veinss right here that's actually going
to be the opening of the left pulmonary
veins and they're going to be taking
blood from the left lung and taking and
dumping into the left atrium again
remember that this left side is only
getting oxygenated blood the right side
is adding deoxygenated blood so
oxygenated blood
here gets pumped down right through this
valve right here this is called the
mitral valve or the bicuspid valve right
then it has these little collagen cords
dangling down from the leaflets which
are going to be again are called the
chordae tendineae and if you look right
there 154 you can see the papillary
muscles right there which anchor the
chordae tendineae down alright guys so
what I wanted to do is I want to take
another view right here to look inside
of the ventricles you can see this
little valve right here this is called
the aortic semilunar valve so again the
aoritc semilunar valve is what prevents
the back flow from the aorta into the
left ventricle I just want to give you
guys another look at that that's your
aortic semilunar valve right there and
we look you see all this thick part here
this structure this is called the
interventricular septum and certain
types of defects and like the tetralogy
of fallot there can actually be a little a
little septal defect there where
actually blood can jet between the two
all right now next thing is if you look
here which we can kind of highlight all
of this muscular layer which again is
made up of cardiac muscle right so all
of this is cardiac muscle right here
cardiac muscle cardiac muscle we get
that specific layer a name and we call
this part the myocardium all right the
lining the internal chambers of the
heart which can be any part anything
allowing the internal chambers of the
ventricles any internal chamber of the
atria and he's in lining the valves
contains a simple squamous epithelial
tissue which is actually going to be
consisting of a little bit of areolar
connective tissue and we call that
endocardium alright endocardium it again
aligns the internal chambers of the
heart and the valves alright so again
guys you can see the anterior part of
this right so now what I'm going to do
is I'm going to take this piece off here
so we can kind of look at some of the
more internal structures inside here so
if you look there's actually going to be
these little muscle linings right here
so a little muscle tissue again and to
your walls of the atria and they're kind
of hard to see it's actually kind of
looks like someone combed them they're
called the pectinate  muscle so pectinate
muscles are up here in the anterior wall
of the atria right and then down here
you can see all these gnarled irregular
fibers of muscle this is called the
trabeculae carne and the trabeculae
carne is only in the anterior walls of
the ventricles against the trabeculae
carnae and the anterior walls of the
ventricles and
pectinate muscles here in the anterior walls
of the atria alright so now that last
thing to kind of wrap everything up for
the hard guys if you look the outer
layer of the heart is actually
consisting of a specific type of tissue
that actually can call mesothelium and
what it's made up of it actually the
outer layer is actually called the
epicardium but it's made up of simple
squamous epithelial tissue with a little
bit of aerial or connective tissue and
it's again it's going to be covering
outer part of this heart right here
alright so if you remember in our videos
on structures and layers of the heart we
go into more detail on that but again
just showing the anatomy here this outer
layer of the heart is going to be
consisting of epicardium which is a made
up of simple squamous epithelial tissue
a little bit of areolar connective
tissue and again you can call that
mesothelium alright that pretty much
takes care of everything for the heart
see ya ninja nerds!
