2. Innate Defenses
External defense
skin, etc..
pH=3-5

3. Mucus Membranes

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

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

6. 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

7. 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

8. 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

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

10. -includes vessels (with valves) -fluid (lymph) -organs
Lymphatic system
-includes vessels (with valves)
-fluid (lymph)
-organs
Important cells are T lymphocytes and B lymphocytes
These cells are involved in specific immunity
“immune response”

11. Produces antibodies in response to specific antigens
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

12. 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

13. -do not produce antibodies -”killer 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
-”killer cells”
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. 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

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

18. 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

19. 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

20. Allergies Hypersensitivity to environmental antigen (allergen)
Antibodies attach to
mast cells
pollen bridges
the gap causing
degranulation
Histamine & other
Inflammatory agents
released

21. 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)

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

23. 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

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

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

26. 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