The lymphatic system helps fight infection, remove waste, maintain fluid balance, and absorb fats. It consists of lymph, lymphatic vessels, lymphatic tissue, and red bone marrow. Lymphatic vessels begin as capillaries that absorb fluid and transport it through larger vessels and lymph nodes. The spleen filters blood and stores blood cells. Disorders of the lymphatic system include lymphedema, lymphangitis, and lymphadenopathy.

1. Lymphatic System
Vinod Kumar Mugada
Associate Professor
Department of Pharmacy Practice
VIPT

2. Importance
•Fighting infection
•Removing waste
•Maintaining fluid balance
•Absorbing fats

3. Fighting infection
Lymph nodes and other structures
•Help to filter and trap foreign substances,
such as viruses and bacteria, and
•Trigger an immune response to attack and
eliminate them.

4. Removing Waste
•Remove waste products, such as dead cells,
from the body.
•This is important for maintaining healthy tissue
function and preventing the buildup of harmful
substances.

5. Maintaining fluid balance
Helps to drain excess fluid from
tissues and return it to the
bloodstream, preventing swelling
and edema

6. Absorbing Fats
Involved in the absorption of fats
and fat-soluble vitamins from the
digestive system, and their
transport to the bloodstream.

7. Lymphatic system
Lymphatic system consists of
1. Lymph
2. Lymphatic vessels
3. Lymphatic tissue- a specialized form of reticular connective
tissue that contains large numbers of lymphocytes.
4. Red Bone Marrow

8. Lymphatic vessels and lymph circulation
• Lymphatic vessels begin as lymphatic capillaries.
• These capillaries, which are in the spaces between cells,
are closed at one end.
• Lymphatic capillaries unite to form larger lymphatic
vessels.
• Tissues that lack lymphatic capillaries include avascular
tissues (such as cartilage, the epidermis, and the cornea
of the eye), portions of the spleen, and red bone marrow.

9. Lymphatic capillaries
• Lymphatic capillaries have greater
permeability than blood capillaries
and thus can absorb large
molecules such as proteins and
lipids.
• Lymphatic capillaries have a
unique one-way structure that
permits interstitial fluid to flow into
them but not out.
• The ends of endothelial cells that
make up the wall of a lymphatic
capillary overlap
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10. Lymphatic capillaries
•When pressure is greater in the interstitial fluid than
in lymph, the cells separate slightly, like the opening
of a one-way swinging door, and interstitial fluid
enters the lymphatic capillary.
•When pressure is greater inside the lymphatic
capillary, the cells adhere more closely, and lymph
cannot escape back into interstitial fluid.

11. Lymphatic capillaries
•In the small intestine, specialized lymphatic
capillaries called lacteals (LAK-tē-als; lact- = milky)
carry dietary lipids into lymphatic vessels and
ultimately into the blood.
• The presence of these lipids causes the lymph
draining from the small intestine to appear creamy
white; such lymph is referred to as chyle (KĪL =
juice). Elsewhere, lymph is a clear, pale-yellow fluid.

12. Lymphatic capillaries
• Attached to the lymphatic capillaries are
anchoring filaments, which contain elastic
fibers. They extend out from the lymphatic
capillary, attaching lymphatic endothelial
cells to surrounding tissues.
• When excess interstitial fluid accumulates
and causes tissue swelling, the anchoring
filaments are pulled, making the openings
between cells even larger so that more
fluid can flow into the lymphatic capillary.
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13. Lymph trunks and ducts
• As lymphatic vessels exit lymph nodes in a particular region of the body, they unite
to form lymph trunks.
• The principal trunks are the lumbar, intestinal, bronchomediastinal, subclavian, and
jugular trunks.
• The lumbar trunks drain lymph from the lower limbs, the wall and viscera of the
pelvis, the kidneys, the adrenal glands, and the abdominal wall.
• The intestinal trunk drains lymph from the stomach, intestines, pancreas, spleen,
and part of the liver.
• The Bronchomediastinal trunks drain lymph from the thoracic wall, lung, and
heart.
• The subclavian trunks drain the upper limbs. The jugular trunks drain the head

15. Formation of lymph
• More fluid filters out of blood capillaries than returns to them by reabsorption.
• The excess filtered fluid—about 3 liters per day—drains into lymphatic
vessels and becomes lymph.
• Because most plasma proteins are too large to leave blood vessels,
interstitial fluid contains only a small amount of protein.
• Proteins can't go back into the blood once they've left it because there's
more of them in the blood vessels than outside.
• However, they can go into the lymphatic vessels and be brought back into
the bloodstream. So, the lymphatic vessels help return the proteins and
plasma that were lost from the blood.

17. Flow of lymph
Respiratory pump.
• Lymph flow is also maintained by pressure changes
that occur during inhalation (breathing in).
• Lymph flows from the abdominal region, where the
pressure is higher, toward the thoracic region, where it
is lower.
• When the pressures reverse during exhalation
(breathing out), the valves in lymphatic vessels prevent
backflow of lymph.

18. Skeletal Muscle Pump
When you're standing still,
the valves in both
directions of the veins in
your leg are open. This
means blood is flowing
upwards towards your
heart.
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19. Skeletal Muscle Pump
• When you contract your leg
muscles, like when you stand on
your toes or take a step, the vein in
your leg gets compressed.
• This helps push the blood towards
the heart through the valve closest
to it.
• This squeezing action is called
milking. As the blood gets pushed
through, the valve farther from the
heart closes to prevent any blood
from flowing back down.
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20. Skeletal Muscle
Pump
After you relax your leg muscles, the
pressure decreases in the compressed
part of the vein.
This causes the valve closest to the
heart to close.
As a result, the valve farther from the
heart opens because the blood pressure
in your foot is now higher than in your
leg, which allows blood to flow from your
foot into the vein. Then, the valve
closest to the heart opens again.
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21. Spleen
• It is in the left hypochondriac region between the
stomach and diaphragm.
• In adults, the spleen is about the size of an
avocado.
Your spleen:
• Stores blood.
• Filters blood by removing cellular waste and
getting rid of old or damaged blood cells.
• Makes white blood cells and antibodies that
help you fight infection.
• Maintains the levels of fluid in your body.
• Produces antibodies that protect you against
infection.
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22. • A capsule of dense connective tissue surrounds the spleen and is covered in turn
by a serous membrane, the visceral peritoneum.
• Trabeculae extend inward from the capsule.
• The capsule plus trabeculae, reticular fibers, and fibroblasts constitute the stroma
of the spleen; the parenchyma of the spleen consists of two different kinds of tissue
called white pulp and red pulp.
• White pulp is lymphatic tissue, consisting mostly of lymphocytes and
macrophages arranged around branches of the splenic artery called central
arteries.
• The red pulp consists of blood-filled venous sinuses and cords of splenic tissue
called splenic cords or Billroth’s cords.
• Splenic cords consist of red blood cells, macrophages, lymphocytes, plasma cells,
and granulocytes. Veins are closely associated with the red pulp.

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24. •Blood flowing into the spleen through the splenic artery
enters the central arteries of the white pulp. Within the
white pulp, B cells and T cells carry out immune
functions, similar to lymph nodes, while spleen
macrophages destroy blood-borne pathogens by
phagocytosis.
•Within the red pulp, the spleen performs three functions
related to blood cells: (1) removal by macrophages of
ruptured, worn out, or defective blood cells and
platelets; (2) storage of platelets, up to one-third of the
body’s supply; and (3) production of blood cells

25. Disorders of lymphatic system
• Lymphedema: This is a condition where the
lymphatic fluid accumulates in the tissues, causing
swelling and discomfort. It can be primary (inherited)
or secondary (resulting from damage or obstruction of
the lymphatic system).
• Lymphangitis: This is an inflammation of the
lymphatic vessels caused by bacterial infection. It can
cause redness, warmth, and tenderness in the
affected area.

26. Disorders of lymphatic system
Lymphadenopathy: This is a condition where the
lymph nodes become swollen and enlarged due to
infection, cancer, or autoimmune disease.
Lymphoma: This is a type of cancer that affects the
lymphatic system. It can occur in the lymph nodes,
spleen, bone marrow, and other lymphatic tissues.
Hodgkin's lymphoma: This is a type of cancer that
affects the lymphatic system, causing the abnormal
growth of lymphocytes.

27. Disorders of lymphatic system
Non-Hodgkin's lymphoma: This is a type
of cancer that affects the lymphatic system,
causing the abnormal growth of lymphocytes
or lymphatic tissues.
Castleman disease: This is a rare disorder
that affects the lymphatic system, causing
the abnormal growth of lymphatic tissues.

28. Disorders of lymphatic system
Kaposi's sarcoma: This is a type of cancer
that affects the lymphatic system, causing
the growth of abnormal blood vessels.
Elephantiasis: This is a parasitic infection
that can cause the lymphatic vessels to
become blocked, leading to severe swelling
of the limbs and genitals.

29. Disorders of lymphatic system
Chylous disorders: These are rare disorders where the
lymphatic fluid contains too much fat, causing digestive
problems and malabsorption.
Primary lymphedema: This is a genetic condition that
causes lymphatic vessels to form improperly, leading to
swelling and fluid buildup.
Secondary lymphedema: This occurs as a result of
damage to the lymphatic system, such as after cancer
treatment or surgery.