this power point is about the cells and tissues of the immune system in the subject of pathological anatomy and physiology.

1. Cells and tissues of the
immune system
The researcher : Mehrasa Nikandish
Subject : Pathological Anatomy and
Physiology

2. Overview
Introduction
Types of the diseases of the immune system
Type I Hypersensitivity Reaction
Type II Hypersensitivity Reaction
Type III and IV hypersensitivity Reaction
Autoimmune disorders
immunodeficiency states

3. Introduction
The function of immune system
1. It Looks Out for You :
Your immune system works to root out germs and
other invaders that have no business in your
body.
2. It Likes It When You Relax :
Do your best to tame your stress. When you’re
wound up, your immune system doesn’t work as
well as it does when you’re confident about your
challenges.
3. It’s Got Agents Standing By :Other than your
nervous system, your immune system is the most
complex system in your body.
4. It Learns From Your Past : your immune system
is creating a "bank" of antibodies as they are
exposed to illnesses for the first time, enabling
them to fight off future invaders.
Organs and tissues

4. Different types of immunity
Immunity
Adaptive
(acquired/
specific)
Natural :
1.Active
2.passive
Artificial:
1.Active:
vaccine
2.Passive
(serum)
Innate (non-
specific)
In born

5. Cells of the adaptive immunity
Humoral immunity
B Cell Activation: B cells must be activated
by an antigen before they can fight
pathogens. First, a B cell encounters its
matching antigen and engulfs it.
Plasma Cells and Antibody Production:
Plasma cells are activated B cells that
secrete antibodies.
Memory Cells: Most plasma cells live for
just a few days, but some of them live
much longer. They may even survive for
the lifetime of the individual.
Cell – mediated immunity
Helper T Cells: Helper T cells are like the “managers” of
the immune response. They secrete cytokines, which
activate or control the activities of other lymphocytes.
Cytotoxic T Cells: Cytotoxic T cells destroy virus-
infected cells and some cancer cells.
Cytotoxic T cell mechanism: A cytotoxic T cell releases
toxins that destroy an infected body cell and the
viruses it contains
Regulatory T Cells: Regulatory T cells are responsible
for ending the cell-mediated immune response after
an infection has been curbed. They also suppress T
cells that mistakenly react against self antigens

6. Diseases of the immune system
hypersensitivity reactions
Hypersensitivity reactions occur
as one of four types (types I–IV).
Hypersensitivity (also called
hypersensitivity reaction or
intolerance) refers to undesirable
reactions produced by the
normal immune system, including
allergies.
autoimmune disorders
Autoimmune diseases are the
result of a failure in the immune
system to recognize self-
antigens, resulting in production
of antibodies that react against
normal components of cells.
Most of the autoimmune diseases
are associated with one or more
specific antibodies, which can be
identified by laboratory tests to
aid in diagnosis.
immunodeficiency states
Immunodeficiency disorders prevent
your body from fighting infections
and diseases. This type of disorder
makes it easier for you to catch
viruses and bacterial infections.
Immunodeficiency disorders are either
congenital or acquired. A congenital,
or primary disorder is one you were
born with. Acquired, or secondary,
disorders you get later in life.
Acquired disorders are more common
than congenital disorders.

7. Type I Hypersensitivity Reaction
Sequence of events
1. Early phase (occurs within 5–30
minutes of exposure to antigen):
Characterized by vasodilation, increased
vascular permeability, and increased
smooth muscle contraction. The early
phase is due to binding of antigen to IgE
bound to mast cells.
2. Late phase (occurs after 2–24 hours
and lasts for days): Characterized by
infiltration by neutrophils, eosinophils,
basophils, and monocytes, and results in
mucosal damage due to release of
mediators by these recruited
inflammatory cells.
Forms of type I
Systemic anaphylaxis: Due to
parenteral administration of
antigen; for example, a bee
sting or a reaction to
penicillin.
Local reaction: Urticaria
(hives).

8. Type II hypersensitivity is an antibody-
dependent process in which specific
antibodies bind to antigens, resulting in
tissue damage or destruction .If the
antigen is present on cell surfaces, antibody
binding can result in cell lysis through the
in situ fixation of complement. IgM
antibodies (multimeric) are often more
effective in fixing complement than are
than IgG antibodies (monomeric).
Type II Hypersensitivity Reaction

9. Type III and IV hypersensitivity
Reaction
Type III
Type III hypersensitivity reactions are also
termed immune complex reactions.
Complexes of antigen and antibody form in
the circulation and are then deposited in
susceptible tissues; they may also form
directly in the tissue. The latter mechanism
is termed the Arthus reaction , and is
typically seen with repeated insect stings,
where a red swollen lesion develops after a
sting.
Type IV
Type IV hypersensitivity is a cell-
mediated immune reaction. In other
words, it does not involve the
participation of antibodies but is due
primarily to the interaction of T cells
with antigens. Reactions of this kind
depend on the presence in the
circulation of a sufficient number of T
cells able to recognize the antigen. The
specific T cells must migrate to the site
where the antigen is present.

10. autoimmune disorders
1. Type 1 diabetes
The pancreas produces the
hormone insulin, which helps
regulate blood sugar levels. In type 1
diabetes mellitus, the immune
system attacks and destroys insulin-
producing cells in the pancreas.
High blood sugar results can lead to
damage in the blood vessels, as well
as organs like the heart, kidneys,
eyes, and nerves.
2. Rheumatoid arthritis (RA)
In rheumatoid arthritis (RA),
the immune system attacks the
joints. This attack causes
redness, warmth, soreness,
and stiffness in the joints.
Unlike osteoarthritis, which
commonly affects people as
they get older, RA can start as
early as your 30s or sooner .
3. Psoriasis/psoriatic arthritis
Skin cells normally grow and
then shed when they’re no
longer needed.
Psoriasis causes skin cells to
multiply too quickly. The extra
cells build up and form
inflamed red patches,
commonly with silver-white
scales of plaque on the skin.

11. 4. Multiple sclerosis
Multiple sclerosis (MS) damages the myelin
sheath, the protective coating that
surrounds nerve cells, in your central
nervous system. Damage to the myelin
sheath slows the transmission speed of
messages between your brain and spinal
cord to and from the rest of your body.
This damage can lead to symptoms like
numbness, weakness, balance issues, and
trouble walking.
5. Inflammatory bowel disease
Inflammatory bowel disease (IBD) is a
term used to describe conditions that
cause inflammation in the lining of the
intestinal wall. Each type of IBD affects a
different part of the GI tract.
Crohn’s disease can inflame any part of
the GI tract, from the mouth to the
anus.
Ulcerative colitis affects only the lining
of the large intestine (colon) and
rectum.
autoimmune disorders

12. primary immunodeficiency
disorders
If you are born with a deficiency or if there
is a genetic cause, it is called primary
immunodeficiency disease. There are more
than 100 primary immunodeficiency
disorders.
Examples of primary immunodeficiency
disorders include:
X-linked agammaglobulinemia (XLA)
common variable immunodeficiency
(CVID)
severe combined immunodeficiency
(SCID), which is known as
alymphocytosis or “boy in a bubble”
disease

13. Secondary immunodeficiency
disorders
Secondary immunodeficiency disorders happen when
an outside source like a toxic chemical or infection
attacks your body. The following can cause a
secondary immunodeficiency disorder:
severe burns
chemotherapy
Radiation
Diabetes
Malnutrition
Examples of secondary immunodeficiency disorders
include:
AIDS
cancers of the immune system, like leukemia
immune-complex diseases, like viral hepatitis
multiple myeloma (cancer of the plasma cells,
which produce antibodies)

14. Thanks for your attention