Innate Defenses

1
(No Transcript)
2
Innate Defenses
External defense skin, etc..
pH3-5
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
Swelling
Skin surface
Bacteria
Phagocytes and fluid move into area
Phagocytes
Chemical signals
White blood cell
Blood vessel
Tissue injury release of chemical signals such
as histamine
Dilation and increased leakiness of local
blood vessels migration of phagocytes to the area
Phagocytes (macrophages and neutrophils)
consume bacteria and cell debris tissue heals
2
3
1
link
7
Fig. 24-2a
Pin
Skin surface
Bacteria
Chemical signals
White blood cell
Blood vessel
Tissue injury release of chemical signals such
as histamine
1
8
Fig. 24-2b
Swelling
Phagocytes and fluid move into area
Dilation and increased leakiness of local
blood vessels migration of phagocytes to the area
2
9
Fig. 24-2c
Phagocytes
Phagocytes (macrophages and neutrophils)
consume bacteria and cell debris tissue heals
3
10
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
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
Fig. 24-5a
Cell-mediated immune response
Humoral 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
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
Fig. 24-5a
Cell-mediated immune response
Humoral 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
17
(No Transcript)
18
Fig. 24-17a
B cell (plasma cell)
Mast cell
Antigenic determinant
Histamine
Antibodies attach to mast cell
2
B cells make antibodies
Allergen (pollen grain) enters bloodstream
1
3
Sensitization Initial exposure to allergen
19
Fig. 24-17b
Allergen binds to antibodies on mast cell
Histamine is released, causing allergy symptoms
4
5
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
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 doesnt 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 Counteract
ed by epinephrine
25
Autoimmune diseases
Immune system doesnt recognize self and attacks
MS
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