The lymphatic system
throughout the body is vast
and they are very small. So the actually vessels
himself the afferent and the efferent vessels
are very difficult
to pick up themselves.
But we can see the
lymph nodes in most people
if they become infected or they become
full of the lymphocytes that they
are busy in filtering out lots of
debris and they can become swollen.
We can see the lymph nodes in the
groin. We can see some in the neck.
But they are really associated with lots of
organs and we have a high number of lymph nodes
within the abdominopelvic cavity.
Ultimately all of these lymph nodes are
going to drain into the thoracic duct.
They are going to drain into the
thoracic duct, which we can see here.
It runs next to the
oesophagus within the
thoracic cavity. And
it actually drains
into the junction between the left
subclavian and internal jugular veins.
Now, the vast majority of the lymph
from the body is going to be draining into
the thoracic duct and this diagram
actually shows it nicely. All of the body that's
covered in this kind
of pinkish shading
is one way or another going to
drain into the thoracic duct.
Only this upper right
quadrants of the body
doesn't and that drains
via the right lymphatic duct.
But the vast majority of it is
passing through the thoracic duct
into this region here. The junction of the left
subclavian and the internal jugular veins.
Now we're concentrating on
the gastrointestinal tract.
And lymph from the gastrointestinal tract drains into
what are known as the pre-aortic lymph nodes.
These pre-aortic lymph nodes are positioned
anterior to the aorta, pre-aortic.
And they were associated with
the three unpaired arteries.
So we have the coeliac trunk. We
have the coeliac lymph node.
We have the superior mesenteric artery.
We have superior mesenteric lymph node.
We have inferior mesenteric artery.
We have inferior mesenteric lymph node.
And ultimately if we remember the
foregut, the midgut and the hindgut
are served by these blood
vessels. Then the lymph
from those organs will go to their
respective lymph nodes. So the foregut
will pass to the coeliac lymph node.
The midgut will pass to the
superior mesenteric lymph node.
And organs within the hindgut will pass
to the inferior mesenteric lymph node.
Efferent lymphatic vessels
from these nodes
form what are known as
intestinal lymphatic trunks.
And these are sent up the body and ultimately
will converge to form the cisterna chyli.
This occurs around
about L1, L2 level.
We also have organs which are retroperitoneal
and we have the pelvic organs
which are not associated with the
peritoneum; they are sub-peritoneum.
These still give rise to the lymph
and these drain into what are known as
right and left lumbar lymphatic trunks.
These are the same principle as
the intestinal lymphatic trunks
except they come from those retroperitoneal
organs. They come from the pelvic organs.
Ultimately the lumbar lymphatic
trunks and the intestinal
lymphatic trunks unites to form the
cisterna chyli which is this dilation
around about L1, L2. Really its
quite variable in the individual.
It occur around about here receiving the
intestinal, receiving the lumbar lymphatic trunks.
From the cisterna chyli it then continuous
through the diaphragm and it then runs
through the thorax as the thoracic
duct which opens up into the
left subclavian and the internal
jugular veins, the junction of those.