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Immunity Overview
Test 3
73
Microbiology
Undergraduate 3
04/02/2013

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Term
What are the two main mechanisms of defenses?
Definition
Innate and Adaptive
Term
What are your innate defenses considered?
Definition
First line of defense. Non-specific and inheritied.
Term
What are examples of innate defenses?
Definition
1.)Physical barriers
2.)chemical defenses
3.)normal bacterial flora
4.)cell communicators (cytokines)
5.)sensor systems (complements)
6.)Phagocytosis
7.)Fever
Term
What are your adaptive defenses considered?
Definition
The second line of defense if pathogen overtakes innate. Specific, learned and have memory.
Term
What are the two wbc involved with adaptive defenses?
Definition
T-lymphocytes and B-lymphocytes
Term
What are the 3 types of granulocytes?
Definition
1.)Neutrophils
-most abundant
-phagocytes
2.)Basophils
-least numerous
-involved in allergic rxns
3.)Eosinophils
-combat parasitic worm infections
Term
What are the 2 types of agranulocytes?
Definition
1.)monocytes
2.)lymphocytes
Term
What are the 2 cells that a monocyte differentiates into?
Definition
1.)macrophage - phagocyte
in liver, spleen, lymph nodes...
2.)dendritic - phagocyte
APC
Term
What are the 3 cells that a lymphocyte differentiates into?
Definition
1.)t-cells
2.)b-cells
3.)NKC
Term
What is a t-cell?
Definition
Require APC's.

Four main types
-cytotoxic
-helper t
-suppressor t
-memory t
Term
What is a b-cell?
Definition
differentiates into -
1.)plasma cell
2.)memory B cell
Term
What is a natural killer cell?
Definition
NON-SPECIFIC KILLER of cells that have been bound by antibodies or have abnormal traits. use perforins and granzymes to destroy the cells.
Term
What are the 2 physical barriers of the body?
Definition
1.)Skin
2.)Mucus Membranes
Term
The ______ contains tightly woven fibrous connective tissues.
Definition
dermis
Term
The epidermis possesses a water-repelling protein called _____ which makes the skin an arid environment.
Definition
keratin
Term
What do mucus membranes line?
Definition
digestive, respiratory, and urogenital tracts
Term
How does the mucus membrane trap and wash away microbes?
Definition
Constantly bathed in fresh mucus and other body secretions.
Term
What moves microbes towards body openings where they are more easily eliminated?
Definition
Peristalsis & cilia
Term
What are 5 chemical defenses?
Definition
1.)Lyzozymes
2.)Peroxidase Enzymes
3.)Lactoferrin
4.)Defensins
5.)Changing pH
Term
What are lysozymes?
Definition
Enzymes that degrade peptidoglycan.
Term
Where are lysozymes found?
Definition
Body secretions including tears, saliva, mucus, perspiration, tissue fluids, blood, and phagocytic vesicles.
Term
What are lysozymes effective against?
Definition
Gram POSITIVE bacteria because lack of outermembrane
Term
What are peroxidase enzymes?
Definition
Break down hydrogen peroxide to produce oxidizing agents. Potent against catalase-negative organisms.
Term
Where are peroxidase enzymes found?
Definition
saliva, milk, tissue fluids, phagocytic vesicles
Term
What is lactoferrin?
Definition
an iron-binding protein found in saliva, mucus, and milk.
Term
What does lactoferrin make?
Definition
Iron
Term
What are defensins?
Definition
Antimicrobial peptides found in mucus membranes and phagocytic cells.
Term
How do defensins work?
Definition
Insert themselves into bacterial cell membranes creating pores that disrupt membranes integrity
Term
What jucies change pH?
Definition
Urine, gastric juices, and vaginal secretions lower pH

Bile RAISES pH
Term
What is your normal biota?
Definition
Normal growing bacteria on the body surfaces of healthy individuals.
Term
What are its 4 fxns?
Definition
1.)create competition
2.)some produce antimicrobial agents
3.)may block binding sites
4.)cell communication
Term
What are the 2 components of your biota that allows cellular communication?
Definition
1.)surface receptors
2.)cytokines
Term
What are the surface receptors?
Definition
The cell's "ears". Integral membrane proteins that only bind to specific chemicals.
Term
What are the cytokines?
Definition
the cell's "voice". Released by cells in response to invasion. Bind to surface receptors to initiate a change in that cell.
Term
What are 5 important cytokines?
Definition
1.)Chemokines - stimulate chemotaxis
2.)Interferons - produced by virus-infected cells
3.)Colony-stimulatiing factors - multiplication and differentiation
4.)INterleukins - function in innate defense, inflammation, adaptive immunity
5.)Tumor necrosis factor - kill tumor cells, inflammatory response, programmed cell death
Term
What is the sensor system
Definition
Detect the presence of microbial ivasion or tissue damage.
Term
What are the two types of sensor system?
Definition
1.)Toll-like
2.)Complements
Term
What is the toll-like receptor?
Definition
Located on the membranes of certain host cells. Detect specific chemicals/structures associated with microorganisms and initiate immune response.
Term
What is the complement system?
Definition
Series of normally innactive circulating proteins. Increase the activity of antibodies.
Term
How many complements are there?
Definition
9. C1-C9
Term
What are the 3 outcomes that come from the complement system?
Definition
1.)inflammation
2.)foreign cell lysis
3.)opsonization
Term
What complements cause the inflammatory response?
Definition
c3a and c5a increase permeability and act as chemoattractants
Term
What complements cause foreign cell lysis?
Definition
c5b, c6, c7, c8, c9 aggregate within the membrane creating holes. Gram - most succpetible
Term
What complements cause opsonization?
Definition
c3b coats the surface of the foreign cell making it sticky and more easily phagocytized
Term
What are the steps of phagocytosis?
Definition
1.)chemotaxis
2.)adherance
3.)engulfment
4.)phagolysosome formation
5.)destruction and digestion
6.)exocytosis of residual bodies
Term
What are residual bodies?
Definition
by-products of the destruction of the antigen
Term
What is one of the strongest indicators of infectious disease?
Definition
A fever
Term
What does a fever cause cells to sequester?
Definition
zinc
Term
What does fever decrease and increase within the pathogen and the host?
Definition
decrease bacterial metabolism - increase host's defense responses.
Term
What causes a fever?
Definition
A pyrogen that acts on the hypothalamus
Term
What are the 2 types of pyrogens?
Definition
1.)endogenous
2.)exogenous
Term
What are endogenous pyrogens?
Definition
Produced by the host. Ex: cytokines
Term
What are exogenous pyrogens?
Definition
Produced by the invading microbe. Ex: bacterial toxin
Term
What are 4 characteristics of the adaptive immune system?
Definition
1.)antigen-specific
2.)systemic
3.)is learned
4.)has memory
Term
What are the 2 types of adaptive immunity?
Definition
1.)cell-mediated
2.)antibody-mediated
Term
How does cell-mediated immunity work?
Definition
An antigen invades the innate defenses, and then that antigen is taken up by an APC and broken down. Fragments of the antigen mix with MHC proteins on the APC's surface and are recognized by the T-cell and becomes activated. Then, then t-cells divide and differentiate.
Term
What are cytotoxic t-cells?
Definition
CD8 cells. Primarily attack cells infected by viruses or other intracellular microbes, tumor cells and transplanted cells.
Term
What does activation of a cytotoxic t-cell result in?
Definition
Apoptosis of the target cell
Term
We are unaware of how apoptosis occurs but what is speculated?
Definition
1.)secretion of preforin and granzymes
2.)secretion of lymphotoxin into the target cell fragmenting its DNA
Term
What are helper-t cells?
Definition
CD4. DO NOT KILL ANYTHING. Produce a number of interleukins. Stimulate production of other t and b cells.
Term
What is the interleukin that stimulates t-cell proliferation?
Definition
IL-2
Term
What is the interleukin that promotes t-cell growth and production of IgE
Definition
IL-4
Term
What is the interleukin that promotes secretion of IgA?
Definition
IL-5
Term
What are the other two cells they divide into?
Definition
Supressor T and Memory T
Term
When does antibody-mediated immunity occur?
Definition
Only after cell-medaited immunity has failed.
Term
What happens in antibody-mediated immunity?
Definition
Helper t-cells activate the response and stimulate b cells to divide into plasma and memory b cells. The antibody then merges with the antigen and causes a chain of reactions.
Term
What happens once the antigen and antibody bind?
Definition
1.neutralization
2.immobilization
3.attraction of phagocytes
4.enhances phagocytosis
5.stimulate inflammation
6.inhibit antigen metabolism
Term
What are the 5 classes of antibodies?
Definition
1.)IgA
2.)IgD
3.)IgE
4.)IgG
5.)IgM
Term
What is IgA?
Definition
Found in blood plasma, mucus membranes, and breast milk. Prevents pathogens from adhering to epithelia and penetrating tissues.
Term
What is IgD?
Definition
Integral part of B cell membrane. Acts as an antigen presenter.
Term
What is IgE?
Definition
Found mainly in tonsils, skin, and mucus membranes. Stimulates mast cells to release contents and attracts eosinophils to parasitic worm infectiosn.
Term
What is IgG?
Definition
75-85 or circulating antibodies in plasma. Crosses placenta to confer temporary immunity to the fetus.
Term
What is IgM?
Definition
Found on the B cell membrane and circulating in plasma. Presence indicates recent infection.
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