...arterial supply, but I hope it was clear, the difference between the superficial and
deep system.
Just moving back centrally to the heart, I'm now going to work my way downwards to look
at the blood supply from the venous drainage from the lower limbs.
So I've shown you the superior vena cava and the inferior vena cava leading into the right
atrium.
So I've removed a lot of vessels here.
There are a lot of branches on the inferior vena cava, which I've removed and we'll talk
about in future tutorials on the digestive system and the blood supply and drainage of
those various organs.
So just down here, we're now at the level of the L5 lumbar vertebra.
This is where the inferior vena cava bifurcates into its branches.
So you've got the common iliac veins.
You've got the right and left common iliac veins.
So these split into two.
You've got the external and the internal iliac veins.
The external and the internal iliac veins join to form the common iliac vein.
That converges with its counterpart with the inferior vena cava.
So you've got the common iliac vein which splits into the external and internal iliac
vein.
So just before I go any further, I just need to point out another important vein.
You can see running on the anterior surface of these vertebral bodies, you've got a vein
running up and draining into the superior vena cava.
You can see it running up the anterior surface of the vertebral bodies and then draining
into the superior vena cava here.
So this is the azygos vein.
The azygos venous system drains blood from the posterior walls of the abdomen, of the
thorax and abdomen and it drains into the superior vena cava.
This is the azygos vein.
That runs on the right side.
And you've got the accessory and hemiazygos veins, which run up the left side of the vertebra.
So that's the azygos system, which runs on the anterior surface of the vertebral bodies
and drains into the superior vena cava.
So you've got the azygos vein on the right size and you've got the hemiazygos and accessory
azygos veins running up the left side.
So just moving back to where we were, we've got the common iliac veins, which are formed
from the external and internal iliac veins merging.
Working our way down, the external iliacs are formed from the femoral vein and this
long vein which runs down the entire length of the leg on the medial aspect.
This is called the long saphenous vein.
It runs all the way down the medial aspect of the leg to join the dorsal venous plexus
of the foot.
So just going back up again, you've got the external iliac being formed from the femoral
vein and the long saphenous vein.
So the long saphenous vein is a superficial vein.
The femoral vein is a deep vein.
If I just put in the muscle layer, you can see this.
You can see the femoral vein.
It just runs deep into the muscle layer and then the long saphenous vein runs superficially
all the way down the inner leg.
So it's medial.
It runs medially all the way down to the foot where it joins the dorsal venous arch of the
foot.
So that's the long saphenous vein.
So the long saphenous vein and the femoral vein join into the external iliac vein.
Just working our way down to the back of the knee now, we're now in the popliteal fossa
region.
That's the back of the knee is called the popliteal fossa.
The vessels at the back of the knee are popliteal vessels.
So you've got a popliteal artery here and you've got the popliteal vein here, which
joins into the femoral vein.
So this is the popliteal vein and you can see the long saphenous vein here running all
the way down the medial side.
So the popliteal vein has a branch, the anterior tibial vein, which goes here down the anterior
aspect of the aspect (just like the anterior tibial artery).
And then you've got these two veins.
You've got the peroneal vein, which is also known as the fibular vein because it runs
on the fibula side, so the peroneal muscle group or the lateral muscle group of the lower
leg.
This vein which comes off the popliteal vein is the peroneal vein and this runs on the
lateral side.
So it's also known as the fibular vein, so it runs on the side of the fibula, which is
lateral.
And you've also got the posterior tibial, the counterpart to the anterior tibial vein.
This runs down the posterior aspect of the tibia.
And then you've got another superficial vein.
This is the short saphenous vein.
Remember the long saphenous vein which runs all the way up the medial aspect of the leg,
the short saphenous vein runs centrally down the back of the leg and it's superficial.
It's quite hard to understand, to see and judge the depth.
The deep veins are these posterior tibial veins and the peroneal veins and the superficial
veins are the saphenous veins, the long saphenous which runs all the way down the medial aspect
and the short saphenous which comes off the popliteal vein here.
The short saphenous vein runs down the back of the calf muscle and then it winds around
laterally and joins to form the dorsal venous arch of the foot, this arch here.
So remember the long saphenous vein which runs down the medial side join to form the
venous arch, the other side of the venous arch is formed by the short saphenous vein,
which runs down the middle of the calf and then winds around laterally.
So in the lower leg, you've got superficial and deep veins.
A deep vein thrombosis occurs in the deep veins of the legs.
A deep vein thrombosis can occur all the way up into the femoral vein, which is also a
deep vein -- so this vein, this thick vein here.
An important thing to be aware of isn't actually shown in these models is that you have veins
which connects the deep and superficial veins, perforator veins which contain the deep to
the superficial veins.
Blood flows from superficial to deep.
So if valves become incompetent in the veins of the leg, blood may then accumulate in the
superficial veins, so in the long and short saphenous veins, which then become swollen
and torturous and you get varicose veins.
So that's what varicose veins are.
Those are the important veins of the body that you should be aware of.