My Power Point Presentation on the Immune/Lymphatic Systems. The damn animations and emphasis' better work I have spent more time with them than adding the content.

1. WORKING TOGETHER
The Lymphatic and Immune Systems

2. WHY DO WE NEED AN IMMUNE
SYSTEM?
Yes, they do.
But: they are non-specific defenses.

3. REVIEW OF KEY TERMS

Antigen

Antibody

Primary Reaction

Secondary Reaction

Macrophage

4. WE NEED SPECIFIC DEFENSES TOO.
B cells and T cells accomplish this.
B cells are important for antibody induced
immunity in body fluids
T cells are important for cell based immunity.
(Think abnormal cells and pathogens in cells)

5. FIRST LET’S REVIEW NON-SPECIFIC
DEFENSES:

Integumentary system

Phagocytes in blood and tissues

Complement

Fever and Inflammation
But it is not enough!

6. 3 CELL TYPES OF THE IMMUNE SYSTEM
Lymphocytes
“The militia”
Phagocytes
“The janitors”
NK cells
“The ninjas”

7. PHAGOCYTES
First line of defense, often attack and remove
microorganisms before lymphocytes (T cells and B
cells) detect them.
2 Types
Microphages – patrol blood
Macrophages – patrol peripheral tissue

8. SPECIFIC DEFENSE CELL 1: T CELLS
Thymus dependent cells, recognize antigens when bound to special
proteins in a cell membrane, called MHC proteins.
4 Types of T cells

Cytotoxic- highly mobile, seek out and destroy abnormal
or infected cells
“think detective”

Helper- activate B cells so they are able to produce
antibodies
“think keys”

Suppressor- Keep the immune system from overreacting
“think bouncer”

Memory- on 2nd exposure automatically transform to cytotoxic
T cells.

9. SPECIFIC DEFENSE CELL 2: B CELLS
2 types of B cells
B cells - Bone marrow derived cells, each carries its own
specific antibody molecule that fits a corresponding
antigen. Needs the Helper T cells to activate and
stimulate their division. They will eventually divide into
plasma cells and Memory B cells.
B memory cells – on second exposure they divide into
plasma cells that secrete antibodies in massive
quantities*.
*How massive?
-When stimulated by cytokines from a T cell, plasma cells can
secrete up to 100 million antibody molecules an HOUR

10. T CELL ACTIVATION
When a macrophage (“think pac-man”)
engulfs a pathogen with an antigen on it, the
antigens are presented to the T-cell by placing
them on its cell membrane at the MHC.
The T-cell then is able to recognize and bind to the
antigen there and begin dividing.

12. B CELL ACTIVATION
On their surface B cells have specific antibodies that
bind with specific antigens.

B cells engulf the antigen and present it on their cell
membrane to be recognized by an activated Helper T cell,
which gives the B cell the “go ahead”.


The T-cell attaches to the part of the B cell membrane
where the antigen is and begins to secrete cytokines to
activate the B cell.

The B cell can now divide, accelerate plasma cell
formation, and enhance antibody production.

14. REMEMBER THE DIFFERENCE!
Primary Response
Secondary Response
-
Antibodies do not peak
until 1-2 weeks after
exposure
-
Even low antigen
concentrations will
immediately trigger
memory B cell response.
-
IgM are first to appear,
but do not create memory
cells. Immediate, but
limited defense
-
Antibodies increase rapidly
and reach much higher
concentrations than with
the primary response
-
IgG rises more slowly and
creates memory cells.
Takes over response.
-
Invading organism is often
destroyed before symptoms
appear.

15. TYPES OF ANTIBODIES

IgA – Found in secretions of the body.

IgD – Found on the cell membrane of B cells.



IgE – Found wherever IgA is. Thought to be
involved in triggering allergic reactions.
IgG – Primarily recognizes bacteria, viruses, and
toxins.
IgM – a very large antibody that binds to food
and incompatible blood cells.

16. HOW ANTIBODIES ATTACK ANTIGENS
Phagocyte recognition and destruction
Antigens clump together and are targeted by
macrophages
The toxic portion of the antigen is covered
Activate complement proteins that form holes in
antigen

18. SO, HOW DOES THE LYMPHATIC
SYSTEM FIT INTO ALL OF THIS?
It’s primary function is the
production, maintenance, and
distribution of lymphocytes!
Remember, those are the T cells and B cells essential
for specific immunity.

19. ORGANS OF THE LYMPHATIC SYSTEM
The organs of the Lymphatic System include:
Lymph
Lymphatic Vessels
Lymphoid Tissues
Lymphoid Organs
Lymphocytes

20. HOW DOES THE LYMPHATIC SYSTEM
WORK?
More fluid is delivered to tissues than can be
carried away.
 The Lymphatic System’s circulatory network
returns this fluid to the blood stream.
 On the way to the major collecting ducts,
pathogens are filtered at stops such as the spleen
and lymph nodes
 Lymphocytes, produced in the organs of the
lymphatic system, freely flow through this circuit
and patrol.


21. FORMATION OF LYMPHOCYTES



Two different types are produced in the bone
marrow
One type stays there, the other migrates to the
thymus to mature, separated from the blood.
When they have completed maturing they
return to the bone marrow and lymphoid tissues
and organs, such as the spleen.

22. LYMPHOID ORGANS
All lymphoid organs are separated from the
surrounding tissues by a fibrous connective tissue
capsule.
Lymph Nodes
Thymus
Spleen

23. WHAT IS LYMPH?
A thin, watery fluid originating in organs and
tissues of the body.
It circulates through the lymphatic vessels and is
filtered by the lymph nodes.
It enters the blood stream at the junction of the
internal jugular and subclavian veins.

24. FLOW OF LYMPH
Lymphatic capillaries
Small Lymphatic Vessels
Superficial and Deep Lymphatics
Lymph Nodes
Major Lymph Collecting Ducts

25. THE FILTERING PROCESS

Lymph nodes – Purify lymph before it returns to
the venous circulation. 99% of the antigens are
removed.
A T cell may spend 20 hours in a lymph node.
A B cell may spend 30 hours in a lymph node.

26. OTHER ORGANS OF THE LYMPHATIC
SYSTEM


Thymus – the thymus provides a place for
lymphocytes to mature, separated from the
systemic circulation.
The thymus also produces several hormones
that are important to the development and
maintenance of a normal immune system.

27. OTHER ORGANS OF THE LYMPHATIC
SYSTEM

Spleen – Has the largest collection of lymphoid
tissue in the body and does for blood what lymph
nodes do for lymph.
-removal of abnormal blood cells and
components
-storage of iron from recycled red blood
cells
-initiation of immune response by B and T
cells in response to circulating antigens.

28. DISEASES OF IMMUNITY
HIV
Human Immunodeficiency Virus

29. PATHOLOGY OF HIV
Depletes Helper T cells
Circulating antibodies also decrease, and cell
mediated immunity is reduced. (As a result
pathogens that are usually harmless create
opportunistic infections.)
The surplus in suppressor T cells as Helper T cells
die turns off the normal immune response.
Immune surveillance is also decreased, increasing
cancer risk.

30. STAGES OF HIV
Acute Infection
Clinical Latency
AIDS
Large amounts of the virus
are being reproduced in the
body.
HIV reproduces at
low levels, but is still
active
Helper T cell count
falls to dangerously
low levels
Usually occurs within 2-4
weeks of infection
It is still possible to
transmit the virus
After rapid Helper T cell
destruction, immune system
kicks in and body returns to a
viral set point.
This period may last
8 years or longer.
At this stage the
immune system is
badly damaged and
opportunistic
infections are likely.
Survival is typically 3
years with AIDS. It is
only 1 year with an
opportunistic
infection.

31. SURPRISING HIV FACTS
Virus enters the body under clever camouflage,
cloaked in sugar molecules.
 There are different strains of the virus, some
more deadly than others.
 34 million people are living with HIV today.
 Transmission to a fetus from the mother is now
considered entirely avoidable with medication.
 A quarter of AIDS deaths are from TB
