Immune System
Chapter 43
By Christian, James, Mack,
and Nick
Immune System
The Major Defenses
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Skin and mucus= physical barriers that deter
invading bacteria and viruses
White Blood Cells
-Also known as leukocytes.
-Function by phagocytosing bacteria and
debris or by producing antibodies.
-Produced by hematopoietic stem cells in bone
marrow.
-Found in blood and the lymphatic system.
Immune System
Lymphatic System 1
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Components
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Lymphocytes
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Bone marrow
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Lymph nodes
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Spleen
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Thymus
Immune System
Lymphatic System 2
Major Functions
- production of lymphocytes, types of white
blood cell.
-to transport lymph and drain interstitial fluid
from cells so it can be returned to the blood.
Immune System
Lymphatic System 3
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Lymphocytes
- directly destroy tissue
and debris and produce
antibodies.
- 3 types: T cells, B
cells, and Natural Killer
cells.
Immune System
Lymphatic System 4
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T Cells
“soldier” cell = searches and destroys foreign, possible
harmful objects.
Move to the thymus gland in the neck where they mature.
Become active in response to the release of thymosin.
Produce cytokines which are signaling molecules that
work in cellular communication.
Cytoxic T Cells= able to cause the death of infected cells.
Helper T Cells= no phagocytic activity.
-activate cytoxic T cells and B cells.
Immune System
Lymphatic System 5
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T Cell Recognition
Consists of 2 polypeptide chains connected
by a disulfide bridge.
Receptor= 1 antigen binding site
Can detect antigens on the surface of
infected cells called Major Histocompatibility
Complex (MHC) molecules
Immune System
Lymphatic System 6
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B Cells
Mature into either plasma cells or memory B
cells.
Mature to produce an anti body against the
antigen which caused its production.
Mature in bone marrow
Immune System
Lymphatic System 7
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B Cell Recognition
Receptor contains 4 polypeptide chains
Trans membrane portion anchors the
receptor in the cell
Receptor= 2 antigen binding sites
B cell binds to its antigen by non-covalent
bonds
Immune System
Lymphatic System 8
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Natural Killer Cells
Have activating receptors which activate the cell
when it comes in contact with its target.
Specialize in killing cells that are cancerous or
infected with a virus.
They contain special proteins in their cytoplasm,
such as perforin and granzymes, that are meant to
enter the target cell and cause it to go through
apoptosis, or programmed cell death.
Immune System
Lymphatic System 9
Bone Marrow
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Produces blood cells
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B cells and NK cells
develop here
Immune System
Lymphatic System 10
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Lymph Nodes
These structures
contain T cells, B cells,
dendritic cells and
macrophages.
Here, B and T cells
filter antigens out of the
lymph
Drain fluid from other
tissues.
Immune System
Lymphatic System 11
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Spleen
Filters blood
Contain B cells, T cells,
macrophages, dendritic
cells, natural killer cells
and red blood cells.
Macrophages and
dendritic cells bring
antigens to lymphocytes
in the spleen to be
destroyed.
Immune System
Lymphatic System 12
Thymus
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T cells migrate to the
thymus from the bone
marrow.
Here they are
“educated” into Mature
T cells.
After they mature, they
are released into the
blood stream.
Immune System
Lymphatic System 13
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Other Types of Cells
Granulocytes or Polymorphonuclear (PMN)
Leukocytes : engulf bacteria and parasites. Then
they degrade the debris with their enzymes.
Macrophages: carry antigens to other cells ( B and T
cells) so that they can be destroyed,
Dendritic Cells: capture antigens and bring them to
the organs of the lymphatic system.
Phagocytes: Cells that chew up invading organisms
and degrade them with internal enzymes, a process
called phagocytosis.
Immune System
Lymphatic System 14
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Phagoctyic Cells
Neutrophils: 60-70% of white blood cells.
- attracted to infected tissue
- engulf and destroy microbes, foreign microorganisms, in
infected tissue
-self destruct in the process of phagocytosis.
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Eosinophils: attach themselves to a parasitic body and inject
fatal enzymes into the target.
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Macrophages: develop from monocytes, a type of white
blood cell.
-”big eaters”
Immune System
Antimicrobial Proteins
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Interferons are
produced by already
infected cells.
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provide defenses by
inhibiting viral
reproduction in
unaffected cells.
Immune System
Other Important Organs
Adenoid and Tonsils
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Lymphatic tissues
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Defend the body
against germs that we
breathe in through our
noses and mouths.
Immune System
Other Important Organs
Appendix
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House good bacteria
that may boost immune
system help and white
blood cell production.
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Directs white blood
cells to injured area.
Immune System
First Response: Inflammation
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Triggered by physical injury or the presence of
antigens.
The release of histamine by mast cells makes
capillaries in the affected area grow larger, allowing
more blood to flow to the area and the activation of
macrophages.
Chemokines signal and direct phagocytes to the
affected areas.
The capillaries leak fluid which leads to swelling.
Blood clotting helps stop the spread of microbes.
Immune System
Immune Response
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Primary Immune Response: Plasma cells and T cells
are activated.
-10-17 days after infection
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Secondary Immune Response: occurs when
the body has already been exposed to the
antigen.
-greater amount of antibodies produced.
-2- 7 days after infection
Immune System
Antibodies (Immunoglobulins)
Antibody
IgM
Function
Promotes the neutralization and
aggregation of antigens.
IgG
Marks antigens for phagocytosis
along with promoting the
aggregation and neutralization of
antigens.
IgA
Provides mucus with its defense
against antigens.
IgE
Triggers the release of histamine.
IgD
Acts as an antigen receptor.
Immune System
Immunity
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Innate Immunity: General immunity that
everyone is born with.
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Adaptive Immunity (Active Immunity): Antibodies we
develop as we are exposed to viruses.
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Passive Immunity (Passive Immunity): Immunity
borrowed from another source.
Exercise 1: Parts of the Human Immune System. Your immune
system is composed of various organs, all of which work to
defend your body against the many microorganisms that enter
into your body everyday.
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Below is a diagram of the
human immune system and
descriptions or names of
several of the main organs that
take part in defending your
body against invaders.
a.) Match their number with the
letter of the corresponding
organ on this diagram.
b.) Find the name of all of the
organs described below.
c.) Describe the function of
each organ that is already
named for you.
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1.) The organ located by your heart that is the site of T-Cell maturation. ________.
____ 2.) The organ which filters and removes foreign cells from the blood. ________.
____ 3.) Bone Marrow. ____________________________________________________
________________________________________________________________________
_______________________________________________________________________.
____ 4.) Lymphoid follicles that are found in the mucosa layer of the small intestine.
________.
____ 5.) Lymph Vessels. ___________________________________________________
________________________________________________________________________
_______________________________________________________________________.
____ 6.) Organ which swells with trapped bacteria and other microorganisms during an
infection, and eventually kills them with germ fighting cells. ________.
____ 7.) Appendix. _______________________________________________________
________________________________________________________________________
_______________________________________________________________________.
____ 8.) Tonsil. __________________________________________________________
________________________________________________________________________
_______________________________________________________________________.
____ 9.) Located near the back of the nose, it helps defend against infection by trapping
microorganisms coming in through the body. _________.
____ 10.) Provides a first line of defense against diseases, by preventing microorganisms
and other germs from entering into your body in the first place. Not can it act as a form of
early warning system through the use of Langhans cells, but it also secretes an
antibacterial substance, which causes most bacteria that lands on it to die soon afterwards.
_________.
Exercise 2: Types of White Blood Cells. White blood cells, or leukocytes, are types of
blood cells the body manufactures to fight off infection and foreign invaders.
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a.) Below is a matching column containing information relating to the five main types of
white blood cells: Neutrophils, Eosinophils, Basophils, Monocytes, and Lymphocytes. Add
the first letter of each of these types of white blood cells to the phrase that describes it; ex.
Place an “L” in front of the phrase that describes Lymphocytes. If the phrase describes all
white blood cells in general, place an “A” in front of the phrase.
1. ___Can act as Langerhan cells within the skin.
2. ___Includes the type of cells that produce antibodies.
3. ___Includes the type of cells that can detect and kill body cells infected virally.
4. ___Numbers of these cells in the blood increases with the number of parasites and
allergens.
5. ___Primarily kills parasites found in the skin and lungs.
6. ___Many of these mononuclear leukocytes come to together to form microphages.
7. ___Produced within the bone marrow.
8. ___Most common white blood cell found in the body.
9. ___Has a very short life span compared to that of the leukocytes.
10. ___Carry histamine, allowing them to start the process of inflammation.
11. ___These dead remains of these leukocytes are the primary components of pus, which
forms when an infection gets severe.
12. ___The smallest, and the most numerous types of white blood cells within the human
body.
13. ___Digests foreign microorganisms and old or dead body cells, such as pus.
14. ___Breaks down bacterial cells through the use of enzymes.
15. ___Mainly travels in the blood, but can come into contact with other tissue via the
lymphatic channel of the Lymphatic System.
16. ___Attracted to foreign material and bacteria by a process known as chematoxis, in
which cells move towards a region of higher chemical concentration.
17. ___Helps keep the body safe from foreign organisms or materials that could be harmful
to your body.
18. ___Start out in the bone marrow as stem cells, but can mature into either B Cells or T
Cells.
Exercise 2: Types of White Blood Cells. White blood cells, or
leukocytes, are types of blood cells the body manufactures to fight
off infection and foreign invaders.
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b.) Fill in each letter you obtained from the matching column
above next to their corresponding number below.
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1.___ _G_ 2.___ 3. ___ 4. ___ _U_ _K_ 5. ___ 6. ___ _I_ 7. ___ 8. ___ _O_ 9. ___ 10. ___
11. ___ 12. ___ _S_ 13. ___ 14. ___ _Y_ 15. ___ 16. ___ _F_ 17. ___ 18. ___
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c.) Hidden in the mess of letters above should be the name of a
cancer that targets the white blood cells of the human immune
system. Not only does this cancer cause the white blood cells
to come out abnormal, but because the cells do not die when
they should, they accumulate in large numbers, which could
possibly impairing the effectiveness of the normal blood cells.
What is the name of this cancer?
Exercise 3: Immune Response. Your immune response is the way your body
fights off invading bacteria, viruses, and other foreign material.
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a.) There are three different types
of immunity your body can take
advantage of to fight disease:
Innate, Acquired/Adaptive, and
Passive. Innate immunity relates to
the natural defenses of the human
body, which includes barriers that
keep harmful material out of your
body. Acquired, or adaptive relates
to our defense against diseases
that is built up throughout our
lifetime. Passive Immunity relates to
situations where your body
strengthens its immune system
using antibodies from outside
sources. Using the chart below,
give examples of each type of
immunity.
Innate
Immunity
Acquired/A
daptive
Immunity
Passive
Immunity
Online Sources:
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http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookIMMUN.html
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http://uhaweb.hartford.edu/BUGL/immune.htm
http://nobelprize.org/educational_games/medicine/immunity/immunedetail.html
http://biology.clc.uc.edu/Courses/bio105/immune.htm
http://medicalcenter.osu.edu/patientcare/healthcare_services/infectious_d
iseases/im
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http://www.niaid.nih.gov/topics/immunesystem/Pages/default.aspx
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