The lymphatic circulatory system, it is
the second type of circulatory system
which is present in our body. Now like in
the blood circulatory system, the blood
was the fluid which was present or
which flows through the blood vessels.
Similarly, in the lymphatic circulatory
system it is the lymph which flows
through the lymphatic vessels. So, let's
observe this lymphatic circulatory
system in detail. So, while observing this we
will first see that the lymphatic
circulatory system mainly has three
components like the blood circulatory
system had. So, what are these components?
Let's see, the first one it is the lymph
which is the fluid, the circulating fluid.
The second or in here we'll write as B is
the lymphatic vessels. So, like the blood
vessels this system it also has
vessels and these are the lymphatic
vessels. The third in here is the
lymphatic organs. So, in case of blood
circulatory system we have learned that
it is the heart but here we call them
lymphatic organs. So now, first let's
observe the lymph. So, what is lymph? Well
we have learned that blood is a fluid
connective tissue which has various
components in it, similar to that is the
lymph. Now, how it is so? Let's see. So, as
the artery, it carries the blood it
bifurcates to form thin capillaries, it
bifurcates
to form thin capillaries and we have
learned that these thin capillaries they
combine to form of a vein, right? So, these
are the capillaries of mine and here
they
collectively form a big vein. Now, if I
see in here I will make these as the cells.
Consider that these are the cells or
simply tissues. So, this is our artery,
this is our vein, these are the
capillaries and these are the cells. So
now, what will happen? The blood it will
carry oxygen, this oxygen will be carried
by these veins. Now, the veins as they are
porous, a lot of fluid that is the plasma
it oozes out into these tissues
basically into the interstitial spaces
or the spaces which are present between
these cells. So, what happened is that
along with the nutrients or basically
when we talk about gases etc., a lot of
blood fluid it ozess out in the
spaces between the cells. Now, some of their
it gets accumulated in here,
okay. So, some of it they get back into
the capillaries so that they you know
can be removed with the help of vein. But
still some of the fluid which is given
out by the capillary it gets accumulated
between the various cells spaces,
okay. And this fluid is what we call the
tissue fluid or the lymph,
Okay? This is what we call as issue fluid
or the lymph. So, I repeat,
let's take an example if i say like hundred
ml of blood has been given by the artery,
Okay? Now, out of this hundred ml let's
say that 90 percent of the fluid present
in the blood it gets into the tissues.
But out of this ninety percent of the
fluid
ten percent remains in the tissue as
the tissue fluid, remaining it moves
again into the veins,
Okay. So, this is how we formed the tissue
fluid or the lymph. Now, we'll look into
the composition of lymph, we will see that
lymph, it contains mainly the blood plasma
and the WBC's it means that unlike blood
which contain plasma, RBCs, WBCs as well
as platelets lymph contains only the
plasma and the WBCs. So, it means that from
the lymph the rbcs and platelets are
absent. Also, from this plasma the large
proteins are absent. As the large protein
cannot squeezed out of these you know
minute pores of the capillaries the lymph,
it does not contain the large proteins
it does contain protein but in a very
small amount and that to the smaller
ones. So this is the composition of lymph.
Lymph also contains some cell debris or you
know some kind of bacterias etc which
are all present in the tissue fluid. So,
this is the lymph. Now, moving forward if
we see the lymphatic vessels so now, what
are lymphatic vessels and how does this,
you know the tissue fluid which is
present between the cells it gets
drained out? Because it is very very
harmful if this tissue fluid does not
get drain out it is so, because this may
cause swelling. So in some diseases such
as, in let's say the elephantiasis which
is caused by a worm, filarial worm, right?
So, in that disease basically this tissue
fluid it remains in here and that is why
the swelling occurs in the foot and that
is why we call it elephantiasis because
the foot becomes in you know such as
large as of elephant's foot,
Okay, So, this tissue fluid it is very
important to drain it out. How does it
happen? Let see in here so, when we observe
this tissue, let's make it again in here
we will see that this is the capillary
and around these capillaries we have
seen that there are tissues or the
cells present. So, let's make these cells
in here and here the tissue fluid is
present, right? Now, from this tissue fluid
like the blood vessels are present in
the tissues or around the cells
similarly there are thin capillaries
present and these capillaries are called
as lymphatic capillaries, so these are
lymphatic capillaries. Now, some lymphatic
capillaries they combine together to
form a lymph vessel.
Okay. So this is the lymphatic capillary
which arises or which comes out of this
tissue okay and some of these
capillaries these capillaries will
combine to form a lymphatic vessel. Now,
some lymphatic vessels they combine to
form large ducts so, lymphatic vessels
they combine to form two large ducts
mainly this is called as, this side will
be called as right thoracic lymph duct
and
on this side there will be one left thoracic
lymph duct, okay. So, the right
thoracic lymphatic duct and the left
thoracic lymphatic duct. Now, these ducts
majorly their function is like this
right side one it for its function is to
collect the lymph from the right part of
the body mainly from the head neck from
the right hand etc. so, it connects the
blood from the right part of the body.
Now, similarly the left thoracic duct it is
the largest, you know lymphatic duct and
this largest lymphatic duct it carries or
it collects the lymph from left part of
the body and also from the lower from
the posterior region, from the abdominal
region etc. so, this is the largest
lymphatic duct. Now, these two ducts these
two lymphatic ducts they mainly combine.
So, the mainly combined with the left and
right subclavian vein, I'll tell you what
are they? Yes.
So, first we will see this, this is the
again right subclavian vein and this
one in here it is the left subclavian
vein, okay. So, I say that the right and left
thoracic lymph duct they combine into the
right and left subclavian vein, so
ultimately what we have seen? We have
seen that, the lymphatic vessels they
combine again with the veins. In fact if
we see the structure of these lymphatic
vessels the structure is very much
similar to the veins. So, as the veins are
thin
similarly these lymphatic vessels are
also very thin. Next important feature that
they share is, the veins they have
valves and the lymphatic vessels also
have valves, the only difference is that
the lymphatic vessels have larger number
of values as compared to the veins but,
their structure is very very similar.
Now, these right and the left subclavian
vein they combine together to form the
superior vena cava,
Okay. So, they combine to form superior vena
cava. Now, this blood will be drain into
the heart for the further purification.
So, let's repeat and see what we have
seen till now? We have seen, that the
capillaries which drain or you know
which give out the
tissue fluid. This tissue fluid which is
present between the cells it is
collected by the lymphatic capillaries,
these are very thin capillaries like the
blood capillaries but their pores are
comparatively larger as compared to the
blood capillaries so, they collect more
number of substances in them. Now, various
number of blood capillaries or either
lymphatic capillaries they combine
together to form the lymphatic vessel.
Number of lymphatic vessels they combine
together to form two major lymphatic
ducts which are the right thoracic and
the left thoracic lymphatic ducts. These
right and left thoracic lymphatic ducts
they combine into the right and left
subclavian veins, these subclavian veins
they rejoin to form superior vena cava.
So, at the end all the material that has
been left in the tissues they are all
collected back into the vein for the
further purification. Now, I would like to
add a point in here which is that from
the intestine so, if we make it in
here
from the intestine basically the
lymph vessels which arises they are
called the lacteals. These are the
lacteals so, the lacteals they appeared
milky white in color because their main
function is to absorb the digested fat
As we have learned the intestines they
contain the digested nutrients. So, the
lacteals which are present in this
intestine, okay?
They appear milky white in color and
this milky-white lymph that is present
in them is called is kile, okay. Now, they
combine together to form a bag like
structure and this bag like structure it
opens into the left subclavian vein and
this bag like structure is what we
called cisterna chyli.
This is cisterna chyli and
this is a bag like structure which is
formed by the collection of lacteals,
which are given out by the intestine
and this opens into the left
subclavian vein,
Okay? So, this was about the lymphatic
vessels. Moving forward let's observe,
what are the lymphatic organs? So, the
lymphatic organs are the organs which
are formed by the lymphatic tissue. There
are various lymphatic organs present in
our body and they are present all around
the body. For example, first let's see the
lymph nodes,
Okay? Second we can call the spleen then
the thymus, next is the Payer's patches
and also the tonsils.
So, these are all the lymphatic organs
which are present in our body. Now first
when we see the lymph nodes
these are the most important ones and we
see that the lymph nodes are nothing but
when the lymphatic vessels they you know
interact or basically when they you know
cover each other, they form node like
structures which are called lymph nodes.
They are bean like structures and the
lymph nodes they are present all around
our body but they are mainly present or
the major number of them they are
present in the armpit,
Okay. They are also present in the groin,
they are present in the abdomen and most
of them they are present in the neck
region,
Okay? So, these are the lymph nodes. Now,
important point that what are their
function? Well the lymph nodes their main
function is to filter the lymph. So,
firstly they produce lymphocytes like T
and B lymphocytes okay, they produce the
lymphocytes. Next when we see, the next
function is that they destroy the
bacterias which are present. They filter
out the lymph etc. so, these are the
function of lymph nodes. Some diseases in
us they can you know imflammate the lymph
nodes and because of that the lymph
nodes can get swollen, okay? Such as in
AIDS. In AIDS, this happens basically the
AIDS virus which is the HIV virus it
basically inflammate or it attacks the
lymph nodes and due to the inflammation
the lymph node gets that swollen, okay. Next
when we talk about this spleen. Spleen is
the largest lymphatic organ,
its main function as we have learned
that it acts as a blood bank etc. the
spleen also act like a lymphatic organ.
Next is the thymus. Thymus is a gland,
if you remember we have learned that thymus
is a place where the maturation of some
lymphocytes take place so when we had
learned about the B and the T
lymphocytes we have learned that the
thymus is a place for the maturation of
T lymphocytes,
Okay. Next is the Payer's patches which is
present in the wall of small intestine.
So, in the intestine the Payer's
patches are present and these are the
lymphatic organs. Last is the tonsils, the
tonsils they are present on the oral
cavity and they are again considered as
the lymphatic organs. So, student in this
lesson we have learned the lymphatic
circulatory system in which first we had
seen the lymph, which is the fluid which
flows through the lymphatic vessels. This
fluid is slightly different from the
blood as it lacks the RBCs and the blood
platelets, some large proteins that also
absent from this lymph. So, it is only
consisting of plasma And the WBCs mainly
with the lymphocytes, ok and some amount
of antibodies itself. Now, the
lymphatic vessels these are mainly
concerned with the collection of this
tissue fluid which is left between the
spaces of the cells and finally the
lymphatic vessels they get combined with the
veins. So now, all these substances that
have come from the artery they are all
collected back in the vein ultimately, okay.
Lastly we have seen the lymphatic organs
which have a function basically to form
the lymphocytes, they formed the
antibodies and they also destroy the
bacterias they filter out the lymph. So, this
was about the lymphatic circulatory
system.
