This document discusses the lymphatic system. It describes how lymph fluid is formed from interstitial fluid through filtration in capillaries and collects in lymph vessels. Lymph contains white blood cells and travels through lymph nodes before draining into veins. The lymphatic system helps fight infection through immune responses in lymph nodes and transports lipids and vitamins. Common lymphatic disorders include lymphedema from obstruction, lymphadenopathy from infection or disease, and lymphomas which are cancers of lymph tissue.

1. Dr. Rukhsana Anwar

3. Lymphatic organs and tissues
 Primary lymphatic organs are red bone
marrow and the thymus glands. Stem cells in
red bone marrow give rise to mature B cells
and to pre-T cells. T cells migrate in thymus
and mature there.
 Secondary lymphatic organs include lymph
nodes, spleen and lymphatic nodules. These
are the sites for immune responses.

6. LYMPH FLUID
 Lymph fluid is the clear interstitial fluid that
is found between the cells of the human
body. This fluid enters the lymph vessels
by the method of filtration through the
pores that are present in the walls of
capillaries.
 The secreted lymph then travels to any
one or more of the lymph nodes before
emptying eventually into the right or the
left subclavian vein where it mixes back

7. LYMPH FORMATION
 Due to continuous exchange of substances
between the cells and the interstitial fluid, its
composition continuously changes.
 As interstitial fluid forms at the arterial end of the
capillaries, due to the higher blood pressure that
it flows under when compared to veins, most of
it returns to the venous ends.
 However, the rest enters the lymph capillaries
as lymph.

9. LYMPH COMPOSITION
 Lymph has a composition that is quite similar to
that of interstitial fluid. However, it may differ
slightly based on the type of tissue that it is
draining. Lymph contains cells like white blood
cells. The concentration of lymphocytes, a type
of white blood cell, is higher in the lymph fluid
when it leaves a lymph node.
 It has no RBCs and larger proteins.
 Chylomicrons are rich in triglycerides, lipids
enters in lacteal. Whereas, protein is 10 times
high in lymphatic vessels of liver as compared

10. LYMPH CIRCULATION
There are certain tubular vessels that are
responsible for transporting lymph back into the
blood stream, thus, ultimately replacing the volume
of blood lost during interstitial fluid formation.
 These channels through which lymph flows are
known as lymphatic channels. Since there is no
central pump in the lymphatic system, unlike the
cardiovascular system, lymph still travels from one
center to another.
 This occurs even under low pressure due to the
propulsion of lymph through the lymphatic channels
by contraction and relaxation of the smooth muscles,
valves and due to adjacent arterial pulsation.

12. Functions 0f Lymphatic System
 Draining Interstitial Fluid
 Lymphatic vessels transport lipids and
lipid soluble vitamins (ADE & K) absorbed by
the GIT to the blood
 Facilitating immune response.
Lymphocytes and macrophages recognize
foreign cells, microbes, toxin & cancer cells.
.

13. Functions
 System respond 2 ways:
 Lymphocyte T cells destroy the invader
cells causing them to rupture or releasing
cytotoxic substances.
 Lymphocytes B cells differentiate in
plasma cells, which secret antibodies that
combine with specific foreign substances

14. Lymph Disorders
 There are many lymphatic system diseases
that can eventually affect the composition or
flow of lymph. These diseases normally affect
the lymph nodes. These include:
 Lymphedema is the condition where there is
obstruction of the lymphatic system. In this
condition, there is fluid build up which leads to
edema and swelling. This may occur due to
either obstruction due to an overgrowth or due
to an infections

15. Disorders
 Lymphadenopathy is an increase in the size of the
lymph nodes. This normally signifies the presence of
an infection or disease in the body.
 Lymphadenitis is a condition where there is
inflammation of the lymph node and the lymphatic
system.
 Lymphoma is a type of cancer that arises from the
lymph nodes. In this condition, the lymphocytes
undergo changes and start to multiply uncontrollably.
Lymphatic system is an important part of the body's
defense system which helps to fight off infections,
most of which is carried out by this clear fluid.