in this site me aboy miey and izun will explain futher about lymphatic system. Enjoy

1. KHAIRUL HADI ROZI TEE
(D20141066254)
TUAN HAZLAMI BIN RAJA ABU HASAN
(D20141066248)
IZUN BIN ITHNIN
(D20141066854)

2. DEFINITION

3. Introduction of Lymphatic
System
 Consists of organs, ducts, and nodes. It
transports a watery clear fluid called lymph. This
fluid distributes immune cells and other factors
throughout the body.
 It also interacts with the blood circulatory
system to drain fluid from cells and tissues. The
lymphatic system contains immune cells called
lymphocytes, which protect the body against
antigens (viruses, bacteria, etc.) that invade the
body.

4. Structure of lymphatic

5. Main of Structure

7. MAIN FUNCTIONS
 Maintain fluid balance
 Defend the body against
disease by producing
Lymphocytes
 Absord fats

9. What is Lymphocytes
 A type of blood cell and important part of
immune system
 Defend the body against infection because
they can distinguish the body’s own cell from
foreign ones.
 They recognize foreign material in the body,
they produce chemical to destroy that
material.

10. Type of lymphocyte before birth
Lymphocytes B Lymphocytes T
 Stay within the bone
marrow untill they
are mature.
 Once mature, they
spread throught the
body and concentrate
in spleen and lymph
nodes.
 Leave the bone
marrow and mature in
the thymus
 A gland found in the
chest
 Only mature
Lymphatic can carry
out immune responses.

11. Lymph Nodes
 Lymph Nodes are small but very
important structure in the lymphatic
system, which is part of the larger
immune system in the body.
 These nodes act as filters, removing
harmful particles and fighting off
bacteria.
 Lymph nodes found at neck, armpits,
groin, and behind knees.

12. LYMPH NODES
( ENCAPSULATED MASSES OF LYMPATIC TISSUE )
 Lymph nodes are an important component of the
body's immune system and help in fighting infections.
 Lymph nodes are located throughout the body, but
visible and palpable only when they are enlarged or
swollen.
 They are small, soft, round or oval structures that are
found throughout the body.
 They are connected to each other in chain-like
(lymphatic chains) fashion by channels similar to blood
vessels.
 Each individual lymph node is covered by a capsule
made up of connective tissue.
 Within the capsule, lymph nodes contain certain kinds
of immune cells.
 These cells are mainly lymphocytes, which produce
proteins that capture and fight viruses and other
microbes, and macrophages, which destroy and remove
the capturedmaterial.

14.  Lymph nodes often swell in one location when a problem
such as an injury, infection, or tumor develops in or near the
lymph node.
Which lymph nodes are swollen can help identify the problem ?
 The glands on either side of the neck, under the jaw, or behind the ears
commonly swell when you have a cold or sore throat.
 Glands can also swell following an injury, such as a cut or bite, near the
gland or when a tumor or infection occurs in the mouth, head, or neck.
 Glands in the armpit (axillary lymph nodes) may swell from an injury or
infection to the arm or hand. A rare cause of axillary swelling may be
breast cancer or lymphoma.
 The lymph nodes in the groin (femoral or inguinal lymph nodes) may
swell from an injury or infection in the foot, leg, groin, or genitals. In rare
cases, testicular cancer, lymphoma, or melanoma may cause a lump in
this area.
 Glands above the collarbone (supraclavicular lymph nodes) may swell
from an infection or tumor in the areas of the lungs, breasts, neck, or
abdomen.

15. Lymph nodules
( Small unencapsulated masses of lymphatic tissue )
 Found beneath the epithelium of all mucous
membranes, that is, the tracts that have natural
openings to the environment.
 Destroy pathogens that penetrate the epithelium of
the respiratory, digestive, urinary, or reproductive
tracts.
Tonsils are the lymph nodules of the pharynx ;
peyer’s patches are those of the small intestine.

16. Example of lymph nodes

17. Tonsils
 The tonsils (palatine tonsils) are a pair of soft tissue
masses located at the rear of the throat (pharynx)
 Each tonsil is composed of tissue similar to lymph
nodes, covered by pink mucosa (like on the adjacent
mouth lining)
 Running through the mucosa of each tonsil are pits,
called crypts
 The tonsils are part of the lymphatic system, which
helps to fight infections.
 removal of the tonsils does not seem to increase
susceptibility to infection.
 Tonsils vary widely in size and swell in response to
infection.

18. Example of tonsils

19. SPLEEN
SPLEEN
The spleen is a brown, flat, oval-shaped lymphatic organ that
filters and stores blood to protect the body from infections
and blood loss.
Protected by our ribs, the spleen is located between the
stomach and the diaphragm in the left hypochondriac region
of the abdominal body cavity. The splenic artery branches off
from the aorta and the celiac trunk to deliver oxygenated
blood to the spleen, while the splenic vein carries
deoxygenated blood away from the spleen to the hepatic
portal vein. A tough connective tissue capsule surrounds the
soft inner tissue of the spleen

23.  Spongy inner tissue within the spleen contains many tiny blood
vessels and hollow sinuses that store blood. The spleen can release
its stored blood into circulation to replace blood lost during a
traumatic injury. Many platelets are also stored with the blood in
the spleen to help form blood clots to prevent further blood loss.
 Around the vessels and sinuses of the spleen are regions of red
pulp and white pulp with a marginal zone in between.
 The red pulp regions contain many net-like reticular fibers that filter
worn-out red blood cells from the blood flowing through the
spleen. Captured red blood cells are digested to recycle the iron
and protein components of hemoglobin.
 The marginal zone between the red and white pulp acts as a filter
to capture pathogens in the blood and pass these pathogens on to
the white pulp.
 White pulp regions of the spleen are made of lymphatic tissue
containing macrophages, T lymphocytes, and B lymphocytes that
destroy pathogens in the blood and produce antibodies. The spleen
may enlarge during certain infections due to an increase in the
number of white blood cells, captured pathogens and antibodies
inside the spleen.

24. Inside the spleen

25.  The spleen is not a vital organ – its functions
are useful but not essential for life.
 Red bone marrow, the liver, and lymph nodes
can complete the filtration and blood
recycling functions of the spleen in its
absence.
 Because it is not a vital organ and is so soft,
spongy, and vascular, damage to the spleen is
almost always treated by its complete
removal.
 Untreated damage to the spleen can quickly
lead to massive internal hemorrhaging and
eventual death.

26. Thymus gland
 The thymus gland, despite containing glandular tissue
and producing several hormones, is much more closely
associated with the immune system than with the
endocrine system. The thymus serves a vital role in the
training and development of T-lymphocytes or T cells,
an extremely important type of white blood cell. T cells
defend the body from potentially deadly pathogens
such as bacteria, viruses, and fungi.
 The thymus is a soft, roughly triangular organ located in
the mediastinum of the thoracic cavity anterior and
superior to the heart and posterior to the sternum It has
two distinct but identical lobes that are each
surrounded by a tough, fibrous capsule. Within each
lobe is a superficial region of tissue called the cortex
and a histologically distinct deep region called the
medulla. Epithelial tissues and lymphatic tissues
containing dendritic cells and macrophages make up
the majority of both regions of the thymus.

27. Image of Thymus

29.  The function of the thymus is to receive immature T cells that are
produced in the red bone marrow and train them into functional,
mature T cells that attack only foreign cells. T cells first reside within
the cortex of the thymus where they come in contact with epithelial
cells presenting various antigens. The immature T cells that respond to
the antigens corresponding to foreign cells are selected to survive,
mature, and migrate to the medulla while the rest die via apoptosis
and are cleaned up by macrophages. This process is known as positive
selection.
 Upon reaching the medulla, the surviving T cells continue to mature
and are presented with the body’s own antigens. T cells that bind to
the body’s own antigens test positively for autoimmunity, whereby
they attack the body’s own cells instead of only foreign cells.
Autoimmune T cells are eliminated by apoptosis in a process known as
negative selection, resulting in only around 2% of the immature T cells
reaching maturity.
 Several hormones produced by the thymus promote the maturation
of the T cells prior to their release into the bloodstream. The now
mature T cells circulate through the body where they recognize and
kill pathogens, activate B cells to produce antibodies, and store the
memory of past infections.

30.  Unlike most organs that grow until the age of
maturity, the thymus enlarges throughout
childhood but slowly shrinks from the onset
of puberty and throughout adulthood.
 As the thymus shrinks, its tissues are replaced
by adipose tissue.
 The shrinking is due to the reduced role of
the thyroid in adulthood – the immune
system produces most of its T cells during
childhood and requires very few new T cells
after puberty.

31.  Unlike most organs that grow until the age
of maturity, the thymus enlarges
throughout childhood but slowly shrinks
from the onset of puberty and throughout
adulthood.
 As the thymus shrinks, its tissues are
replaced by adipose tissue. The shrinking is
due to the reduced role of the thyroid in
adulthood – the immune system produces
most of its T cells during childhood and
requires very few new T cells after puberty.

32. Thanks for your attention