In the abdominal region we're going to see the abdominal aorta.
The descending aorta went through the thorax, but we don't get to see it here, passed through
the diaphragm at the T12 vertebral level and became abdominal aorta.
The abdominal aorta has both paired branches and unpaired branches.
The paired branches supply mostly the muscle walls, with a few exceptions.
And the unpaired branches supply the viscera of the abdomen.
At T 12 we see two things happening here on this model.
It really looks like one.
This vessel is branching from the aorta and coming up on the bottom of the diaphragm.
There should be two of those, one on each side.
This is called the inferior phrenic artery.
The next vessel comes out and it's called the celiac trunk.
And it branches into three branches.
And we can see those three branches here.
We can see the splenic artery heading over here to the spleen.
This branch is called the left gastric artery.
And the third branch is the common hepatic artery, going to the liver.
So here we had inferior phrenic.
This other one that branches into three is the celiac trunk.
T 12 vertebral level.
At the L1 vertebral level we have an artery coming out called the superior mesenteric
artery, that's going to supply the majority of our small intestine, A little bit of the
stomach.
We’ll learn that in lecture.
Also at L1 we have arteries leaving the abdominal aorta going into the kidneys.
Those are the renal arteries.
Then we continue down.
At L2 we have two arteries leaving either side.
Those are the gonadal arteries, going to either the ovaries or the testicles.
If we knew this was a male these would be testicular arteries.
If we knew this was female, these would be ovarian arteries.
At L3 we see the inferior mesenteric artery supplying the lower portion of the large intestine.
And at L4 the abdominal aorta bifurcates into the common iliac arteries.
The common iliac arteries then divide into internal iliac arteries, which will dive into
the pelvis, and extra iliac arteries, which will continue out into the lower extremity
to become the femoral artery.
Also on this plaque, coming from L4 straight down into the pelvis we see what is called
the middle sacral artery.
If we look at the venous supply in the abdomen we can see that this is inferior vena cava
is actually coming up through the abdomen.
Remember that we have started near the feet with the venous drainage and we're going to
bring the blood up from the lower extremities, through the abdominal cavity, through the
inferior vena cava, into the heart.
So if we look in the abdomen we can see that the inferior vena cava is traveling upwards
inside the abdomen.
And it's going to pick up various venous drainage along the way.
Most importantly on this particular model is we can see the renal veins coming from
the kidneys into the inferior vena cava.
Notice those renal veins are passing on this side in front of the aorta and are anterior
to the renal arteries.
So here we see the renal veins coming into the inferior vena cava.
And then the inferior vena cava going up through the vena caval hiatus of the diaphragm into
the right atrium of the heart.
But I want to pay particular attention right here around the liver.
Because here's where the abdomen differs a little bit.
The liver has veins that drain into the inferior vena cava.
And those are called hepatic veins.
And you can see them here in blue draining the liver into the inferior vena cava.
However in the abdomen all your abdominal viscera, your spleen, and your small intestine,
and your large intestine, they all drain into a series of veins which will form what is
called that hepatic portal vein.
That takes blood from the abdominal viscera into the liver.
So on this model you can see here it's kind of a brownish purple color.
Here's the splenic vein and here's one of the other branches of the hepatic portal vein,
and yet another.
All of these will converge to form the hepatic portal vein which goes into the liver.
So the vein going into the liver, hepatic portal vein.
The veins coming out of the liver to the inferior vena cava are hepatic veins.
Do not confuse the two.