Pig heart Anatomy - Lab Video

so today we're looking at the pig heart

and the first thing to do is be able to

tell the anterior surface from the

posterior surface you can kind of tell

there's a jumble of vessels on the back

but what I always use to help me make

sure I'm looking at the front is I find

the pulmonary trunk which has been

dissected on this one but you can see it

has a slightly different coloration to

it and then that will orient me that

okay this is the front of the pig heart

this is the pulmonary trunk therefore

this must be the right ventricle and

then this over here must be the left

ventricle dividing the left and right

ventricle you can see a sulcus right

here it's a little groove we call this

the inter ventricular sulcus and this is

where the left anterior descending

artery flows and if someone has a heart

attack the probability is greatest that

this is the blood vessel that is indeed

clogged okay so then we'll look up a

little bit higher and we can find the

auricles and oracle just means ear and

so here is one on this side this is the

left ventricle so this must be the left

auricle and see it's kind of flappy like

an ear now the article is the part of

the atrium that flaps out like this so

there's actually more space inside of

the atrium but the part of it that forms

this ear like shape is called the Arkell

so if it's pinned from the outside you

say article if it's the chamber is

pinned then you say atrium then you can

find the other flap over on this side so

this would be since this is the right

ventricle then up here this must be the

right Oracle the next vessel to find

would be the aorta so if you this is the

pulmonary trunk and you look right

behind it the large vessel you see

coming up should be the aorta and you

can see how strong and muscular that is

so if you're looking at it from on top

there's the pulmonary trunk going down

to the right ventricle and here's the

aorta going down behind

the pulmonary trunk to the left

ventricle okay now we'll look at the

posterior surface and find a few

important structures here if you think

about blood coming into the heart it has

to come through the superior and

inferior vena cava once you've turned

the heart on its backside now you're

actually looking at the right ventricle

here and this would be the right article

so I'm going to look for the superior

and inferior vena cava dumping into this

area and sure enough although it has

been cut on this one a little bit this

is the superior inferior vena cava if

you want to double check your work

you can stick your finger in there and

see how my finger is now into the right

Arkel and inside of the right atrium

again this is cut right here it's been

dissected normally this would be a tube

so the superior vena cava enters right

here and then the inferior vena cava

enters right here never be afraid to

stick your fingers in there to see where

it goes and then you'll know what vessel

it is okay so that's how blood gets into

the right atrium and then it goes down

to the right ventricle and then it goes

up and out the pulmonary trunk to the

lungs then it comes back to the left

side of the heart so since we're looking

at the back side of the heart this would

be the left ventricle which would make

this the left auricle up here so if you

want to find a path going in to the left

atrium you would look right next to

there and see and sure enough this large

opening goes right into the left atrium

and what this large opening is is

pulmonary veins that have come together

so you had two coming from over here and

two coming from this lung and then those

two this will be the left lung the right

lung and then those pulmonary veins dump

into the left atrium okay so now we're

ready to open the heart up and look at

it so I'm going to go from the front and

this has been dissected to split it

right down the middle so you can open it

up like a book now we'll look at some

structures on the end

the first thing to notice is a large

piece of muscle myocardium that

separates the right ventricle from the

left ventricle notice that the right

ventricle has a thinner muscular wall

than the left ventricle and that makes

sense because the left ventricle has to

plump pump blood out the aorta to the

entire body the right ventricle only has

to pump it up to the lungs which are

right next door so you've got left

atrium and left ventricle and the

ventricles or and the atria are

separated by the AV valves so and

they're held down by these are the

chordae tendineae

those strands right there and then here

is one of the flaps of the bicuspid and

here is the other flap of the bicuspid

that's how it gets its name whereas if

you look on the other side this is the

right atrium and then this is the right

AV valve and it has three flaps to it so

it's often called the tricuspid but it's

also a right to say right AV valve left

AV valve then here's the chordae

tendineae again the chordae tendineae

are held tightly down to the bottom of

the ventricles by these kind of carrot

shaped muscles called papillary muscles

so papillary muscles chordae tendineae

AV valve now the next thing to find are

the semilunar valves so this is the

aorta and you can see that the semilunar

valve right here has been cut so blood

goes into the left atrium left AV valve

up through the aortic semilunar valve

and then to the whole body manual air

okay and then the pulmonary trunk also

has a semilunar valve and you can see it

just by peeking right down in there