Immune System - Biology

1. Immune System
Papio Puga Reyes, V. Regatalio BSPS 1B

2. The Immune
System is the body’s
defense against
infectious organisms
and other invaders
or potentially
damaging foreign
bodies.

3. The immune
system attacks
organisms and
substances that
invade body
systems and cause
disease.

4. Major Components of the Immune System:
Organs related to our Immune
System
• Tonsils
• Adenoids
• Lymph Nodes
• Lymphatic Vessels
• Thymus
• Spleen
• Appendix
• Peyer’s Patches
• Bone Marrow

5. Tonsils
• It is a pair of soft tissue masses
located at the rear of the throat
(pharynx).
• Each tonsil is composed of a tissue
similar to lymph nodes, covered with
pink mucosa (like on the adjacent
mouth lining).
• Running through the mucosa of each
tonsil are pits, called crypts.
• Tonsils vary widely in size and swell in
response to infection.

7. • It is part of the lymphatic
system, which helps to fight
infections. However, the
removal of the tonsils does not
seem to increase susceptibility
to infection.
• It’s main function is to trap
germs (bacteria and viruses) in
which we may breathe.
• The proteins called antibodies
produced by the immune
system cells helps to kill germs
and prevent throat and lung
infection.

8. Adenoids
• Adenoids are a mass of soft tissue located
behind the nasal cavity.
• It is made up of the same type tissue as the
lymph nodes, which is called as the lymphoid
tissue.
• White blood cells circulate through the
adenoids and other lymphoid tissue, reacting
to foreign invaders of the body.
• We all have adenoids at birth and in
childhood, but as we head into adolescence
they start to shrink. By adulthood, most
people’s adenoids have disappeared.

10. Lymph Nodes
• Bean or oval shaped glands or bulbs
that tend to occur in clusters like
grapes.
• The size ranges fro a few
millimeters to about 1-2 cm long.
• Along the lymph channel, there is
approximately 600 lymph nodes.
These act as filters that sieve off the
harmful substances brought by the
lymphatic channels.
• Produces and stores cells that fight
infection and diseases.

12. Lymph Vessels
• It occurs throughout the body alongside
arteries or veins. They are absent from
the central nervous system: bone
marrow, teeth, and avascular tissues.
• It’s a vessel that carry a fluid called
lymph from the tissues to the
bloodstream.
• Mingled among the blood capillaries
throughout our body is another
network of tiny, thin-walled vessels
called the lymphatic capillaries.
• They are designed to pick up the fluid
that leaks into our tissues from our
bloodstream and return it in our
circulatory system.

14. Thymus
• It is a lymphoid gland comprised of two identically
sized lobes, located behind the sternum and in
front of the heart.
• This organ is composed of two types of cells:
 Lymphocytes – It is a type of white blood cells that
is of fundamental importance because they are
cells that determine the specificity of the immune
response to infectious microorganisms.
- It make up 20 to 40 percent of the total number of
white blood cells
- Found in the circulation and also are concentrated
in central lymphoid organs and tissues, such as
spleen, tonsils and lymph nodes.

15. Reticular cells
- it is a form of a loose meshwork, as in a
lymph node, while the spaces between
them are packed with lymphocytes.
- It is a cell forming the stroma of the bone
marrow and lymphatic tissues whose
processes make contact with those similar
cells to form a network.
• It does not have lymphatic vessels draining
into it. It is not a filter like the lymph nodes,
which are situated so that microorganisms
and other antigens are exposed to their
cells.
• It grows rapidly and attains its greatest size
relative too the rest of the body during fetal
life and the first years after birth.

16. • It is situated in the upper thorax.
• It is large in infants and children but
it shrinks as humans grow older.
• It creates specialized white blood
cells that are crucial for the body’s
immune response.
• It is linked to our lymph tissue
development as well as the immune
system.
• It produces hormones that stimulate
general growth, particularly in early
life.
• It has a purifying role in the body
producing lymphocytes, which form
part of the blood’s white blood cell’s
defense system, attacking invading
organisms and providing immunity.

17. • The thymus gland is responsible for
the production of T-cells.
 Behind our thymus, in the center
of our chest, there are 144
AKENEIC or infinite cells. These
cells do not die.
 The electrons that pass through
the atom is core, thereby creating
an infinity LOOP, so that the energy
of these cells never gets lost and
the cell replenishes itself.
 This literally means that cells
cannot die and are DIVINE.

18. Thymus of a Cat

20. Spleen
• It is an organ above our stomach and
under your ribs on your left side.
• It is about as big as our fist.
• It fights infection and keeps our body
fluids in balance.
• It contains white blood cells that fight
germs.
• It helps control the amount of blood in
our body, and it destroys old and
damaged cells.
• It is purple in color and about 4 inches
long.
• The spleen is protected by the rib cage,
and that is the reason why we cant
easily feel it unless it’s abnormally
enlarged.

21. • It acts as a filter for the blood as
part of the immune system.
• The old red blood cells are recycled
in the spleen, and platelets and
white blood cells are stored there.
• It fights certain kinds of bacteria
that cause pneumonia and
meningitis.
• It purifies the blood and helps the
immune system with recognize and
attack foreign antibodies and
disease.

22. Spleen with Tumor

24. Appendix
• Our appendix sits at the junction of
the small intestine and large
intestine.
• It is a thin tube about four inches
long and roughly a quarter of an inch
in diameter.
• Normally, our appendix sits in the
lower right abdomen.
• It acts as a storehouse for good
bacteria, “rebooting” the digestive
system after diarrheal illnesses.

25. • It is a worm-shaped
pouch (its alternate
name is vermiform or
“worm-lile”) attached
to the large intestine.
• It is made of an inner
layer of mucosa.

26. • It helps a person
recover more rapidly
from illness by enabling
the bacteria to re-
colonize the intestines
after the illness had
passed.

28. Peyer’s Patches
• They are small masses of lymphatic
tissue found throughout the ileum
region of the small intestine.
• It is also known as aggregated lymphoid
nodules.
• They monitor intestinal bacteria
populations and preventing the growth
of pathogenic bacteria in the intestines.
• Roughly an egg-shaped lymphatic tissue
nodule that are similar to lymph nodes
in structure, except that they are not
surrounded by a connective tissue
capsule.

29. • It is a non-encapsulated lymphatic
tissue known as the lymphatic
nodules.
• It is to analyze and respond to
pathogenic microbes in the ileum.
• The immune system response by
producing pathogen-specific
antibodies; Turning pathogen-killing
cytotoxic T lymphocytes; migrating
through the lymphatic vessels to
lymph nodes to alert the other cells
of the immune system.

30. • Any of the nodule of the lymphatic cells
that aggregate to form bundles or
patches and occur usually only in the
lowest portion (ileum) of the small
intestine.
• They are usually round or oval and are
located in the mucus membrane lining
of the intestine.
• They can be seen by the naked eye as
elongated thickened areas, and their
surface is free of projections (villi) and
depressions that characterize the
intestinal wall.
• There are 30 to 40 patches in each
individual.

32. Bone Marrow
• It is the soft, flexible connective tissue
within the bone cavities.
• It produces blood cells and stores fat.
• It is highly vascular, meaning that it is richly
supplied with a large number of blood
vessels.
Two categories of the bone marrow tissue:
 Red Marrow – From birth to early
adolescence. The majority of our bone
marrow is composed of the red marrow.
 Yellow marrow – As we grow and mature,
increasing amounts of red marrow is being
replaced by the yellow marrow.

33. • Bone marrow can generate hundreds of
billions of new blood cells everyday.
It is separated into two
 Vascular section – contains blood
vessels that supply the bone with
nutrients and transport blood stem cells
and mature blood cells away from the
bone and into circulation.
 Non-vascular section – it is where
hematopoiesis or blood cell formation
occurs. It contains immature blood cells,
fat cells, white blood cells
(macrophages and plasma cells) and
thin, branching fibers of reticular
connective tissue.

34. • It generates blood cells.
It contains two types of stem cells
 Hematopoietic stem cells – which are
found in the red marrow, and are
responsible for the production of blood
cells.
 Mesenchymal stem cell (multipotent
stromal cells) – produce the non-blood
cell components of marrow, including
fat, cartilage, fibrous connective tissue
(which can be found in tendons and
ligaments), stromal cells that support
blood formation and bone cells.

36. White Blood Cells
• It is also called as leukocytes or
immune cells or white corpuscle.
• These are cells which form a
component of the blood.
• They help to defend the body
against infectious diseases and
foreign materials as part of the
immune system.
• There are normally between 4 x
109 and 11 x 109 white blood cells
in a liter of healthy adult blood
which is about 7,000 to 25,000
white blood cells per drop

37. • In conditions such as leukemia, this
may rise to as many as 50,000 white
blood cells in a single drop of blood.
• White blood cells are found in large
numbers of lymphatic system, the
spleen and in other body tissues
• It is a cellular component of the blood
that lacks hemoglobin, has a nucleus,
is capable of motility, and defends the
body against infection and disease by
ingesting foreign materials and
cellular debris, by destroying
infectious agents and cancer cells, or
by producing antibodies.

38. • Intense physical exertion may cause
the count to exceed 20,000 per cubic
millimeter.
• White cell count also may increase in
response to convulsions, strong
emotional reactions, pain, pregnancy,
labor and certain disease states, such
as infections and intoxications.
• Their survival depends on their
continuous production of energy.
• The chemical pathways utilized are
more complex than those of the red
blood cells.
• They contain a nucleus which
produces ribonucleic acid (RNA) that
can synthesize protein.

39. • Normally, people produce about
100 billion white blood cells in a
given volume of blood is expressed
as cells per microliter of blood.
• Too few or too many white blood
cells indicates a disorder.
• An increase in the number of white
blood cells can also result when
the regulation of WBC
development is disrupted and
immature or abnormal cells are
released into the blood.

40. Antibodies
• It is also called as immunoglobulin.
• It is a protective protein produced by
the immune system in response to the
presence of a foreign substance, called
an antigen.
• They recognize and latch onto antigens
in order to remove them from the
body.
• A wide range of substances are
regarded by the body as antigens,
including disease-causing organism and
toxic materials such as insect venom.

41. • Antibodies are produced by specialized
white blood cells called B lymphocytes
or B cells.
• It stimulates the B cell to divide and
mature into a group of identical cells
called a clone.
• The mature B cells, called plasma cells,
secretes millions of antibodies into the
bloodstream and lymphatic system.
• It attack antigens by binding to them.
• They provide one of the most important
functions of immunity, which is to
recognize an invading antigen and to
produce a tremendous number of
protective proteins that scour the body
to remove all traces of that antigen.

42. • The IgG, the most common antibody,
is present mostly in the blood and
tissue fluids.
• The IgA, is found in the mucous
membranes lining the respiratory and
gastrointestinal tracts.
• Antigens include microorganisms
(such as bacteria, fungi, parasites, and
viruses)
• They are large Y-shaped proteins.
• Both the antibody and the antigen
have similar structure at the tips of
their “Y” structures.
• Just like every lock has a single key, an
antibody has a single antigen key.

43. Complement System
• It helps or complements the ability of our
antibodies and phagocytic cells to clear
pathogens from an organism.
• It is an enzyme cascade that helps defend
against infection.
• It provides the actual protection from the
response while the interaction of antibodies
and antigen provides the specificity of the
response.
• Antibodies “finger” the target, complement
destroys it.
• It consists of some 30 proteins circulating in
blood plasma.
• Most of them are inactive until:
 They are cleaved by a protease which, in
turn, converts them into a protease.

44. • A number of complement proteins
are proteases that are themselves
activated by proteolytic cleavage.
• Such enzymes are called zymogens
and were first found in the gut.
• The precursor zymogens are widely
distributed throughout body fluids
and tissue without adverse effect.
• They are activated locally and
trigger a series of potent
inflammatory events.
• Activated through a triggers-
enzyme cascade.
• An active complement zymogen, to
its active enzymatic form.

45. • The activation of a small number of complement
proteins at the start of the pathway is hugely
amplified by each successive enzymatic reaction,
resulting in the rapid generation of a
disproportionately large complement response.
The system can be activated in two main ways:
• Innate (natural) immune response – neither
antibodies nor T-cell receptors are involved. For
example, certain polysaccharides found on the
surface of bacteria can activate the system. This can
occur immediately and does not require prior
exposure to the molecules.
• Adaptive immune response – when antibodies (IgG
or IgM) binds to antigen at the surface of a cell This
exposes the Fc region of the antibody in a way that
allows the first complement protein (C1) to bind.

47. Interferon
• It is a family of naturally-occurring
proteins that are made and secreted
by cells of the immune system (for
example, white blood cells, natural
killer cells, fibroblasts and epithelial
cells).
• They inhibit viral infections and
stimulates the entire immune system
to fight disease, in response to
pathogens.
• They belong to the large class of
glycoproteins known as cytokines.
• Viral infections of human cells are
inhibited only by human interferon.

48. Three classes of interferons are:
• Alpha – is a man-made copy of protein that
is produced by the body in response to
infection. Helps fight diseases.
• Beta – It also help fight viral infections. They
also work by preventing inflammation and
demyelination in the central nervous
system.
• Gamma – Also known as the type II
interferon which is a pleitropic cytokine
involved in the regulation of nearly all
phases of immune and inflammatory
responses including the activation, growth
and differentiation of T-cells, B-cells,
macrophages, NK cells and other types such
as endothelial cells and fibroblasts.

49. Interferon Alpha
Interferon Beta
Interferon Gamma

50. Diseases - Malfunction

51. Systemic Lupus Erythematosus
• It is an autoimmune disease in which
the body’s immune system mistakenly
attacks healthy tissue.
• It can affect the skin, joints, kidneys,
brain, and other organs.
• It is more common in women than
men,
• It may occur at any age, but appears
most often in people between the ages
of 10 and 50.
• African Americans and Asians are
affected more often than people from
other races.
• This may also be caused by certain
drugs.

52. • Symptoms vary from person to person, and
may come and go. Almost everyone with SLE
has joint pain and swelling.
• The joints of the fingers, hands, wrists, and
knees are often affected.
It affects certain parts of the body:
• Brain and nervous system: headaches,
numbness, tingling, seizures, vision
problems, personality changes
• Digestive tract: abdominal pain, nausea, and
vomiting
• Heart: abnormal heart rhythms
(arrhythmias)
• Lung: coughing up blood and difficulty
breathing
• Skin: patchy skin color, fingers that change
color when cold (Raynaud’s phenomenon)
• Kidney: Swelling in the legs, weight gain

53. Leukemia
• Leukemia is a cancer of the body’s blood-
forming tissues, including the bone
marrow and the lymphatic system.
• It is an abnormal rise in the number of
white blood cells.
• The elevated white blood cells are
immature and do not function properly.
• It is often considered a disease of
children, yet it actually affects far more
adults.
• It is more common in men than in women
and in Caucasians than African -
Americans

54. • The body starts producing more
white cells than it needs.
• Most of the extra white cells do
not mature normally, yet they
tend to live well beyond their
normal life span.
• Leukemia cells are unable to fight
infection the way normal white
blood cells do.
• Certain chromosome
abnormalities have been
associated with leukemia, but
they do not cause it.

55. Multiple Sclerosis
• It is a disease in which our immune system
attacks the protective sheath (myelin) that
covers our nerves.
• Myelin damage disrupts communication
between our brain and the rest of our
body.
• The nerves themselves may deteriorate, a
process that’s currently irreversible.
• MS is not hereditary.
• Having a first degree relative such as a
parent or sibling with MS does significantly
increase an individual’s risk of developing
the disease.

56. • MS is thought to affect more than 2.3
million people worldwide.
• The disease is not contagious or directly
inherited, epidermiologists have
identified factors in the distribution of
MS around the world.
• Most people are diagnosed between
the ages of 20 and 50, although MS can
occur in young children and significantly
older adults.

57. Diabetes, Type 1
• Occurs when the body’s immune system
destroys the insulin-producing cells of the
pancreas (called beta cells)
• The immune system attacks various cells in the
body. This results in a complete deficiency of
the insulin hormone.
 Insulin is secreted by the pancreas in low
amounts. The amount that is released is
proportional to the amount that is required
by the size of that particular meal.
 Insulin is to help move certain nutrients,
especially sugar, into the cells of the body’s
tissues.
• The amount of sugar in the blood decreases
once it enters the cells.

58. • Sugar isn’t moved into the
cells because insulin is not
available in the Type 1
Diabetes.
• Without insulin, too much
glucose stays in our blood.
• This happens most often in
children and young adults but
can appear at any age

59. Crohn’s Disease
• It is a chronic inflammatory disease o the
digestive tract.
• It can occur anywhere in the gastrointestinal
(GI) tract but is most common in the lower
portion of the small intestine (the ileum).
• It is sometimes called regional enteritis
because diseased areas re often interspersed
with healthy areas.
• It persists for a long time.
• Crohn’s Disease can occur in anyone at any
age.
• It affects men and women equally. It most
commonly begins between the ages of 13
and 30.

60. • Smokers are more likely than
nonsmokers to develop Crohn’s.
• People of European Jewish ancestry
have an increased risk of developing
this disease seems to be increasing.
• Crohn’s is more common in
developed nations and in urban
areas.
• As many as 700,000 Americans may
be affected by Crohn’s disease,
according to the Crohn’s and Colitis
Foundation America.

61. Kawasaki Syndrome
• It is a rare childhood illness that affects the
blood vessels.
• It can harm thee coronary arteries, which
carries blood to the heart muscle.
• It is common in children ages 1 to 2 years
and is less common in children older than
age 8.
• It is not contagious.
• It happens most often in the late winter and
early spring.
• The child may be tired and fussy, and his
skin may be dry for a month or so.
• Use skin lotion to help keep the fingers and
toes moist.

62. • It is a form of a condition called vasculitis
(inflammation of the blood vessels,
which include the arteries, veins and
capillaries)
• Sometimes it affects the coronary
arteries that supply oxygenated blood to
the heart.
• It can lead to severe heart problems
including Myocarditis (inflammation of
the heart muscle), Dysrhythmia
(abnormal heart rhythm), and aneurysm
(weakening and bulging of the artery all).
• It is more common in boys than in girls.
• The disease affects more than 4,200
children in the United States each year.

63. Hashimoto Disease
• It is also known as the Chronic thyroiditis or
Hashimoto thyroiditis.
• It is the swelling (inflammation) of the thyroid gland
that often results in reduced thyroid function
(hypothyroidism)
• It is a common thyroid gland disorder.
• It can occur at any age, but is most often seen in
middle-aged women.
• It is caused by a reaction of the immune system
against the thyroid gland.
• It begins slowly.
• It is most common in women and in people with a
family history of thyroid disease.
• It may be related to other hormone problems
caused by the immune system.
• It can occur with adrenal insufficiency and type 1
diabetes.

64. • The condition is called type 2 polyglandular
autoimmune syndrome (PGA II)
• Our immune system attacks our thyroid.
• It is located in front of our neck, the thyroid gland
makes our hormones control metabolism.
It is caused by:
• Genes – suggests a genetic component to the
disease.
• Hormones – affects about seven times as many
women as men. Women have thyroid problems
during the first year after having a baby.
• Excessive Iodine – suggests certain drugs and too
much iodine, a trace element required by our body
to make thyroid hormones, which may trigger
thyroid disease in susceptible people.
• Radiation Exposure – people who are exposed to
radiation, including the atomic bombs in Japan, the
Chernobyl nuclear accident, and radiation
treatment for a form of blood cancer called
Hodgkin’s disease.

65. Rheumatic Arthritis
• It is an autoimmune disease that can cause
chronic inflammation of the joints and other
areas of the body.
• It can affect people of all ages.
• It is characterized by periods of disease flares and
remissions.
• Multiple joints are usually, but not always,
affected in a symmetrical pattern.
• It can cause permanent joint destruction and
deformity.
• The body tissues are mistakenly attacked by their
own immune system.
• The immune system contains a complex
organization of cells and antibodies designed
normally to “seek and destroy” invaders of the
body, particularly infections.

66. • There are about 1.5 million people in the
United States that have Rheumatoid
Arthritis (RA).
• Nearly three times as many women have
the disease as men.
• In women, RA most commonly begins
between ages 30 and 60.
• In men, it often occurs later in life.
• The abnormal immune response causes
inflammation that can damage joints and
organs, such as the heart.
• It protects our health by attacking
foreign substances like bacteria and
viruses.