pH=3-5
Mucus Membranes
Phagocytic cells
Migrate OUT of the blood when the sense differences in concentration of certain chemicals engulf bacteria, dead cells, etc….
Recognize surface molecules on abnormal cells (cancerous or virus infected)
Pin
1 2 3
SwellingSkin surface
Bacteria
Chemicalsignals
Whiteblood cell
Blood vessel
Phagocytes andfluid moveinto area
Phagocytes
Tissue injury; release ofchemical signals such ashistamine
Dilation and increasedleakiness of local bloodvessels; migration ofphagocytes to the area
Phagocytes(macrophages andneutrophils) consumebacteria and celldebris; tissue heals
link
Fig. 24-2a
Pin
1
Skin surface
BacteriaChemicalsignals
Whiteblood cell
Blood vessel
Tissue injury; release ofchemical signals such ashistamine
Fig. 24-2b
2
Swelling
Phagocytes andfluid moveinto area
Dilation and increasedleakiness of local bloodvessels; migration ofphagocytes to the area
Fig. 24-2c
3
Phagocytes
Phagocytes (macrophagesand neutrophils) consumebacteria and cell debris;tissue heals
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”
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
Acquired Immunity (the immune response)
Fig. 24-5a
Humoral immuneresponse
Cell-mediatedimmune response
Lymph nodes,spleen, and
other lymphaticorgans
Final maturationof B and T cells inlymphatic organ
Viablood
T cellB cell
Viablood
Antigenreceptor
Thymus
Antigenreceptor
Immaturelymphocytes
Stem cell
Bonemarrow
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
Fig. 24-5a
Humoral immuneresponse
Cell-mediatedimmune response
Lymph nodes,spleen, and
other lymphaticorgans
Final maturationof B and T cells inlymphatic organ
Viablood
T cellB cell
Viablood
Antigenreceptor
Thymus
Antigenreceptor
Immaturelymphocytes
Stem cell
Bonemarrow
T cells are selected
B cells are selected-antibody producing plasma cells are produced
Person feels ill while these cells are producedSymptoms diminish as these cells do their job
Response is much faster
Memory cells are activated -tend to have a stronger response than the primary
Fig. 24-17a
B cell(plasma cell)
Mastcell
HistamineAntibodiesattach tomast cell
Antigenic determinant
B cells makeantibodies
Allergen (pollen grain)enters bloodstream
Sensitization: Initial exposure to allergen
1 2 3
Fig. 24-17b
Allergen binds toantibodies onmast cell
Histamine isreleased, causingallergy symptoms
Later exposure to same allergen
4 5
Allergies
Hypersensitivity to environmental antigen (allergen)
Antibodies attach to mast cells
pollen bridges the gap causing degranulation
Histamine & other Inflammatory agents released
Active immunityresults from natural recovery from infections
vaccinations
Passive immunityReceive antibodies from someone else
-IgG anitibodies cross placenta-breast milk-shots (rabies treatment)
Transfusions/transplantsABO blood group
-IgM doesn’t cross placenta
Antibodies produced against bacterial antigens which are very similar
rH factor-IgG crosses placenta
Tissue graphs/ organ transplants
Give drugs that suppress cell mediated immunity
Bone marrow transplants
Risk of graft vs host reactionDonor lymphocytes attack host cells
Anaphylactic shock
Acute reaction to allergen
Massive dilation of blood vessels-drop in blood pressure
Counteracted by epinephrine
Autoimmune diseasesImmune system doesn’t recognize “self” and attacks
MS
Insulin dependent diabetes
HIV infection of cells require CD4-found on T cells
Is a retrovirusAntibodies 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