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PowerPoint® to accompany
Medical Assisting
Chapter 29
Second Edition
Ramutkowski  Booth  Pugh  Thompson  Whicker
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1
The Immune System
Objectives
29-1 Spell, define, and correctly use the Key Terms in
this chapter.
29-2 Define the terms infection, pathogen, and
antigen.
29-3 List and describe the nonspecific body defense
mechanisms.
29-4 Explain the signs and causes of inflammation.
29-5 Explain what is meant by specific body defenses.
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The Immune System
Objectives (cont.)
29-6
Define B cells and T cells and describe their
locations and functions.
29-7 Explain the importance of MHC proteins.
29-8 List the different types of T cells and describe
their functions.
29-9 List the different types of antibodies and tell
how they differ.
29-10 Explain how antibodies fight infection.
29-11 Define complement and give its functions.
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The Immune System
Objectives (cont.)
29-12 Explain the difference between the primary
immune response and secondary immune
response.
29-13 Describe the function of a vaccine.
29-14 Explain the four different types of acquired
immunities.
29-15 Describe how allergies develop.
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The Immune System
Objectives (cont.)
29-16 Explain how the AIDS virus affects the
immune system.
29-17 Identify the ways a person acquires AIDS.
29-18 Define cancer and carcinogen.
29-19 Explain how cancers are classified.
29-20 Describe how cancers are diagnosed and
treated.
29-21 Describe the signs and symptoms of other
common immune disorders.
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Introduction
Immune system - protects the body against
 Bacteria
 Viruses
 Fungi
 Toxins
 Parasites
 Cancer
Click for Larger View
6
T and B Cell Activation
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Defenses Against Disease
Infection is the presence
of a pathogen in or on
the body
Nonspecific defenses mechanisms to
protect us against
pathogens in general
Nonspecific Defenses
 Species Resistance
 Mechanical Barriers
 Chemical Barriers
 Fever
 Inflammation
 Phagocytosis
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Specific Defenses
Against Disease
Specific defenses are
called immunities and
protect the body against
very specific pathogens
Lymphocytes and
macrophages are the
major white blood
cells involved in
specific defenses.
Antibodies and
complement are the
major proteins
involved in specific
defenses
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Inflammation
Causes:
 Injured or
infected with a
pathogen,
inflammation
can result
Signs:
 Redness
 Heat
 Swelling
 Pain
10
Apply Your Knowledge
Your 18-year-old patient states that he
thinks his right big toe is inflamed.
What symptoms would you expect to
see?
11
Apply Your Knowledge -Answer
Your 18-year-old patient states that he
thinks his right big toe is inflamed.
What symptoms would you expect to
see?
Redness, heat, swelling, and pain
12
B Cells & T Cells
Two major types of lymphocytes
B Cells and T Cells
Recognize antigens in the body
B cells
Respond to antigens
by becoming plasma
cell - make antibodies
against the specific
antigen
T Cells
Cell-mediated
bind to antigens on
cells and attack
them directly
13
Major Histocompatibility
Complex (MHC)
 Before a T cell can respond to an antigen, it must
be activated
 T cell activation begins when a macrophage
ingests and digests a pathogen that has antigens
 Macrophage then takes some of the antigens
from the pathogen and puts them on its cell
membrane next to a large protein complex
(MHC)
 T cells cannot be activated without macrophages
and MHC proteins
14
T Cells
Helper T cells
 increase antibody formation, memory cell
formation, B cell formation, and phagocytosis
Memory T cells
 memory cells “remember” the pathogen that
activated the original T cell
 person is later exposed to the same pathogen,
memory cells trigger an immune response that is
more effective than the first immune response
15
Antibodies
 IgG - recognizes bacteria, viruses, and toxins. It can
also activate complement.
 IgA - found in secretions of the body such as breast
milk, sweat, tears, saliva, and mucus-prevents
pathogens from entering the body.
 IgM - very large - primarily binds to antigens on
food, bacteria, or incompatible blood cells- activates
complement.
 IgE - found wherever IgA is located- involved in
triggering allergic reactions.
16
Antibodies Fight Infection
 Allow phagocytes to recognize and destroy
antigens.
 Cause antigens to clump together which causes
them to be destroyed by macrophages
 Cover the toxic portions of antigens to make them
harmless.
 Activate complement
 Group of proteins in serum that attack


Pathogens by forming holes in them.
Attract macrophages to pathogens and can stimulate
inflammation.
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Immune Response
 Primary immune response occurs the first time
a person is exposed to an antigen
 slow
 takes several weeks to occur
 memory cells are made
 Secondary immune response occurs the next
time a person is exposed to the same antigen
 very quick
 usually prevents a person from developing a
disease from the antigen
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Types of Immunity
 Naturally acquired active - naturally
exposed to an antigen - usually long
lasting
 Artificially acquired - active-being
injected with a pathogen (immunizations
or vaccines)
 Naturally acquired passive - immunity
through his mother - short-lived
 Artificially acquired passive immunity when he is injected with
antibodies - short-lived
19
Apply Your Knowledge
After you have give an immunization to
a 2-year-old, her mother asks you why
this will work to prevent her from
getting a disease.
20
Apply Your Knowledge -Answer
After you have give an immunization to
a 2-year-old, her mother asks you why
this will work to prevent her from
getting a disease.
Immunization is an artificially acquired
immunity because a person develops this
immunity by being injected with a pathogen
and then subsequently making antibodies and
memory cells against the pathogen.
21
Major Immune System
Disorders
Diseases and disorders that challenge the
immune system: (the following are the
most significant)
 HIV
 Infections
 AIDS
 Cancer
 Allergies
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Acquired Immune Deficiency
Syndrome (AIDS)
Caused by human
immunodeficiency
virus (HIV)
infection
Most common routes of
transmission are
through sexual
contact, blood, or
from mother to child
during pregnancy or
breast-feeding.
Can have infection for
years before
developing any
symptoms of this
disease
Less common routes of
transmission are through
accidental needle sticks,
artificial insemination, and
organ transplants.
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Acquired Immune Deficiency
Syndrome (AIDS) (cont.)
AIDS virus affects
the immune system
 Counts of CD4
cells are used to
diagnose the stage
of HIV infection. If
below 200 patient
has AIDS


CD4 cells are types
of T cells and are
important for the
functions of other
components of the
immune system.
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Acquired Immune Deficiency
Syndrome (AIDS) (cont.)
HIV Testing:
 The most sensitive test, and most expensive
is called the polymerase chain reaction (PCR)
 Determines the number of HIV particles in
a sample of blood.
 Useful in early diagnosis of HIV
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Acquired Immune Deficiency
Syndrome (AIDS) (cont.)
AIDS Testing:
 ELISA – most commonly used test
 Less expensive than PCR test but less
reliable
 Cannot detect early HIV infections
 Counts of CD4 cells are used to diagnose
the stage of HIV infection (CD4 cells are
types of T cells)
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Acquired Immune Deficiency
Syndrome (AIDS) (cont.)
Signs and Symptoms of AIDS:
 Frequent infections
 Low T cell counts
 Some rare forms of
 Fever
cancer
 Profuse sweating
 A common form of
 Weakness
cancer
is
called
 Weight loss
“Kaposi’s” sarcoma.
 Swollen glands
27
Apply Your Knowledge
How can a patient contract HIV?
28
Apply Your Knowledge -Answer
How can a patient contract HIV?
Most common routes of transmission are through
sexual contact, blood, or from mother to child
during pregnancy or breast-feeding
29
Cancer
 Uncontrolled growth of abnormal cells
 Cells often form growths called
malignant tumors
 200 different types of cancers are
known
 Carcinogen - factor that is known to
cause the formation of cancer
30
Cancer (cont.)
The three most common forms of cancer:
 Breast
 Lung
 Colon
Lung cancer is the
leading killer of all
forms of cancer
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Cancer Causes
 Mostly unknown
 Risk factors:
 Suppressed immune system
 Radiation
 Tobacco
 Prevention: Don’t smoke
 A factor that is known to cause cancer is
called a carcinogen.
32
Cancer Diagnosis
 Biopsy - removal of tissues for
examination
 CT scans
 Diagnostic tests
 Blood counts
 Analysis of blood chemistry
 X rays
33
Cancer Treatment
 Treatment differs depending on:
 Type of cancer
 Stage of cancer
 Forms of treatment:
 Surgically removing the tumor
 Chemotherapy
 Radiation therapy
34
Cancer Classifications
Stage 0 - very early
cancer. Cancer cells
are localized in a few
cell layers.
Stage I - spread to deeper
cell layers or some
may have spread to
surrounding tissues.
Stage II - spread to
surrounding tissues but
is considered contained
in the primary cancer
site.
35
Cancer Classifications
Stage III - spread beyond
the primary cancer site
to nearby areas.
Stage IV - spread to other
organs of the body.
Recurrent - Cancer cells
have reappeared after
treatment.
36
Apply Your Knowledge
Your patient has a stage III cancer.
Explain what stage III means.
37
Apply Your Knowledge -Answer
Your patient has a stage III cancer.
Explain what stage III means.
Stage III means that the cancer has spread
beyond the primary cancer site to nearby
areas.
38
Allergies
Allergic reaction is an
immune response
to a substance
Allergens - trigger of
allergic responses
Anaphylaxis - blood
vessels dilate
quickly causing
blood pressure to
drop too quickly
for organs to
adjust. This
condition is life
threatening.
39
Allergies
(cont.)
Allergic reactions involve
IgE antibodies and
mast cells.
IgE antibodies bind to
allergens, they cause
mast cells to release
histamine and
heparin
These chemicals trigger
allergic reactions.
If a person is receiving
allergy shots, he is
being injected with
tiny amounts of the
allergen and reduces
symptoms
40
Diseases and Disorders of
the Immune System (cont.)
Chronic fatigue syndrome - a condition in which
a person feels severe tiredness that cannot be
relieved by rest and cannot be related to another
illness
Signs and symptoms:





Severe fatigue
Mild fever
Sore throat
Tender lymph nodes in neck or armpit
General body aches
41
Diseases and Disorders of
the Immune System (cont.)
Lymphedema - blockage of lymphatic vessels,
which are needed to drain excess fluids from
areas of the body
Signs:
 Swelling that lasts longer than a few days
 Swelling that increases over time
42
Diseases and Disorders of
the Immune System (cont.)
Lupus - an autoimmune disorder that affects few
or many organ systems of the body
Signs:






Arthritis
“Butterfly” rash on face
Sensitivity to sunlight
Renal failure
Headaches
Mental disorders
43
Diseases and Disorders of
the Immune System (cont.)
Rheumatoid arthritis - an autoimmune disorder in
which a person’s immune system attacks joints of the
body
Signs:





Fatigue
Joint pain
Swelling of joints – especially those in hands and feet
Body aches
Cartilage destruction
44
Apply Your Knowledge
As you are taking your patient to the
exam room, you notice that she has
“Butterfly” rash on her face. What
disorder exhibits this sign?
45
Apply Your Knowledge -Answer
As you are taking your patient to the
exam room, you notice that she has
“Butterfly” rash on her face. What
disorder exhibits this sign?
Lupus
46
Summary
Medical Assistant
Knowledge of the immune system will assist you in
providing care for the patient with diseases and
disorders of the immune system.
You must have knowledge of this system when assisting the
physician during the examination of a patient who is having
problems with their immune system.
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End of Chapter
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