1. Immune System

3. Skin Secretions Lysozyme Tears mucus, saliva Innate Defenses
External defenses
Skin
Secretions
pH=3-5
Lysozyme
Tears
mucus,
saliva

4. Mucus Membranes

5. Internal Innate Defense:
Phagocytosis
Phagocytic cells
Migrate OUT of the blood when the sense differences in concentration of certain chemicals engulf bacteria, dead cells, etc….

6. Natural Killer Cells
Recognize surface molecules on abnormal cells (cancerous or virus infected)

7. Inflammatory response
Pin
Skin surface
Swelling
Bacteria
Phagocytes and
fluid move
into area
Phagocytes
Chemical
signals
White
blood cell
Blood vessel 1
Tissue injury; release of
chemical signals such as
histamine 2
Dilation and increased
leakiness of local blood
vessels; migration of
phagocytes to the area 3
Phagocytes
(macrophages and
neutrophils) consume
bacteria and cell
debris; tissue heals
link

8. Pin Skin surface Bacteria
Fig. 24-2a
Pin
Skin surface
Bacteria
Chemical
signals
White
blood cell
Blood vessel 1
Tissue injury; release of
chemical signals such as
histamine

9. Dilation and increased leakiness of local blood vessels; migration of
Fig. 24-2b
Swelling
Phagocytes and
fluid move
into area 2
Dilation and increased
leakiness of local blood
vessels; migration of
phagocytes to the area

10. Phagocytes (macrophages and neutrophils) consume
Fig. 24-2c
Phagocytes 3
Phagocytes (macrophages
and neutrophils) consume
bacteria and cell debris;
tissue heals

11. Lymphatic system includes: -vessels (with valves) -fluid (lymph)
-organs
Important cells involved are T lymphocytes and B lymphocytes
These cells are responsible for specific immune responses to specific pathogens

12. Acquired Immunity (the immune response)
Is highly specific
Produces antibodies in response to specific antigens
Antigens may be molecules on bacteria, viruses, protozoa, worms, transplanted organs
Both B and T lymphocytes have receptors on membrane that recognize different antigens

13. -do not produce antibodies -cytotoxic T cells
B cells
-mature in bone
- produce antibodies
-antibodies float through the blood, recognizing and attaching to antigens
T cells
-mature in thymus
-do not produce antibodies
-cytotoxic T cells
- require cell/cell contact to destroy pathogen
Both B cells and T cells can produce memory cells

14. Humoral immune response Cell-mediated immune response
Fig. 24-5a
Humoral immune
response
Cell-mediated
immune response
Bone
marrow
Stem cell
Thymus
Via
blood
Immature
lymphocytes
Antigen
receptor
Antigen
receptor
B cell
T cell
Via
blood
Lymph nodes,
spleen, and
other lymphatic
organs
Final maturation
of B and T cells in
lymphatic organ

15. Humoral immune response Cell-mediated immune response
Fig. 24-5a
Humoral immune
response
Cell-mediated
immune response
Bone
marrow
Stem cell
Thymus
Via
blood
Immature
lymphocytes
Antigen
receptor
Antigen
receptor
B cell
T cell
Via
blood
Lymph nodes,
spleen, and
other lymphatic
organs
Final maturation
of B and T cells in
lymphatic organ

16. Primary Immune Response
T cells are selected
B cells are selected
-antibody producing plasma
cells are produced
Person feels ill while these cells are produced
Symptoms diminish as these cells do their job

17. Secondary Immune Response
Response is much faster
Memory cells are activated
-tend to have a stronger response
than the primary

18. Primary immune response Antigen receptor (antibody on cell surface)
Fig. 24-7aa-1
Primary immune
response 1
Antigen receptor
(antibody on cell
surface)
B cells with
different
antigen
receptors

19. Primary immune response Antigen receptor (antibody on cell surface)
Fig. 24-7aa-2
Primary immune
response 2 1
Antigen receptor
(antibody on cell
surface)
Antigen
molecules
B cells with
different
antigen
receptors

20. Primary immune response Antigen receptor (antibody on cell surface)
Fig. 24-7aa-3
Primary immune
response 2 1
Antigen receptor
(antibody on cell
surface)
Antigen
molecules
B cells with
different
antigen
receptors 3
First exposure
to antigen
Cell activation:
growth,
division, and
differentiation

21. Plasma (effector) cells secreting antibodies
Fig. 24-7aa-4
Primary immune
response 2 1
Antigen receptor
(antibody on cell
surface)
Antigen
molecules
B cells with
different
antigen
receptors 3
First exposure
to antigen
Cell activation:
growth,
division, and
differentiation
Antibody
molecules 4
Endoplasmic
reticulum
First clone
Plasma (effector) cells secreting antibodies

22. Plasma (effector) cells secreting antibodies Memory cells
Fig. 24-7aa-5
Primary immune
response 2 1
Antigen receptor
(antibody on cell
surface)
Antigen
molecules
B cells with
different
antigen
receptors 3
First exposure
to antigen
Cell activation:
growth,
division, and
differentiation
Antibody
molecules 4 5
Endoplasmic
reticulum
First clone
Plasma (effector) cells secreting antibodies
Memory cells

23. Plasma (effector) cells secreting antibodies Memory cells
Fig. 24-7aa-6
Antigen
molecules 6
Second exposure
to same antigen
Secondary
immune
response (May
occur long after
primary immune
response.)
Antibody
molecules
Endoplasmic
reticulum
Second clone
Plasma (effector) cells secreting antibodies
Memory cells

25. Fig
T cells work by directly binding to infected cells and then destroying them 1
Cytotoxic T cell binds
to infected cell
Self-nonself
complex
Foreign
antigen
Infected cell
Perforin
molecule
Cytotoxic
T cell

26. Perforin makes holes in infected cell’s membrane and enzyme enters
Fig 1
Cytotoxic T cell binds
to infected cell 2
Perforin makes holes in
infected cell’s membrane
and enzyme enters
Self-nonself
complex
Hole
forming
Foreign
antigen
Infected cell
Perforin
molecule
Cytotoxic
T cell

27. Perforin makes holes in infected cell’s membrane and enzyme enters
Fig 1
Cytotoxic T cell binds
to infected cell 2
Perforin makes holes in
infected cell’s membrane
and enzyme enters 3
Infected cell
is destroyed
Self-nonself
complex
Hole
forming
Foreign
antigen
Infected cell
Perforin
molecule
Cytotoxic
T cell

28. Allergies Hypersensitivity to environmental antigen (allergen)
Antibodies attach to mast cells
- later, allergen attaches to these antibodies
on mast cells
Histamine & other inflammatory agents released

29. Antigenic determinant Histamine
Fig a
B cell
(plasma cell)
Mast
cell
Antigenic determinant
Histamine 1
Allergen (pollen grain)
enters bloodstream 2
B cells make
antibodies 3
Antibodies
attach to
mast cell
Sensitization: Initial exposure to allergen

30. Later exposure to same allergen
Fig b 4
Allergen binds to
antibodies on
mast cell 5
Histamine is
released, causing
allergy symptoms
Later exposure to same allergen

31. Anaphylactic shock Acute reaction to allergen
Massive dilation of blood vessels
-drop in blood pressure
Counteracted by epinephrine

32. Active immunity Passive immunity
results from natural recovery from infections
vaccinations
Passive immunity
Receive antibodies from someone else
-IgG anitibodies cross placenta
-breast milk
-shots (rabies treatment)

33. Transfusions/transplants
ABO blood group
-IgM
doesn’t cross placenta
Antibodies produced against bacterial antigens
which are very similar
rH factor
-IgG  crosses placenta

34. Tissue graphs/ organ transplants
Give drugs that suppress cell mediated immunity
Bone marrow transplants
Risk of graft vs host reaction
Donor lymphocytes attack host cells

35. Autoimmune diseases Immune system doesn’t recognize “self” and attacksMS
Insulin dependent diabetes

36. AIDS HIV infection of cells require CD4 -found on T cells
Is a retrovirus
Antibodies are ineffective because
-provirus gives it “invisibility”
-rapid rate of mutation
-Helper T cells decrease
-secondary infections
Drug treatments slow viral replication
-AZT (reverse transcriptase inhibitors)
-protease inhibitors