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Toledo PT Immune System
Toledo PT Immune System
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Physiology
Professional
09/30/2009

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Term
Innate Immunity
Definition
Protects against foreign substanes or cells without having to recognize their specific identities
Term
Adaptive Immunity
Definition
It depends on specific recognition of teh substance or cell to be attacked by lymphocytes
Term
T/F.Innate immunity is mediated by cells and proteins that are always present and called into action upon infection
Definition
True
Term
Major Components of Innate Immunity
Definition
Epithelial barriers of the skin, epithelial barriers of the GI tract, epithelial barriers of teh respiratory tract, phagocytic leukocytes: neutrophils, macrophages, natural killer cells, circulating plasma proteins called complement system
Term
Adaptive Immunity
Definition
Responds to infection by becoming active and expanding and generatign power mechanisms. Major component: lymphocytes.
Term
Two types of adaptive immune response
Definition
Humoreal immunity, Cell-mediated immunity
Term
Humoral Immunity
Definition
Through antibodies produced from B lymphocytes.
Term
Cell-mediated immunity
Definition
mediated by T lymphocytes
Term
Two methods of destruction by microbes
Definition
Bacteria can damage tissue at sites of bacterial replication. Toxins released by bacteria can enter circulation and disrupt function of a certain organ.
Term
Cell Wall
Definition
rigid cell wall composed of peptidoglycan, a protein-sugar molecule. gives thte cell its shape and surrounds the cytoplasmic membrane.
Term
Cytoplasmic membrane
Definition
layer of phospholipids and proteins, caled cytoplasmic membraen, encloses the interior of the bacteria.
Term
Pili & Flagella
Definition
helps attachment to other cells
Term
Capsule
Definition
protective covering; not presenet in some bacteria
Term
Viruses
Definition
nucleic acids surrounded by protein coat. no enzymes,or ribosomes. Must exist in other cells to free load their biomechanical apparatus in order to replicate.
Term
Cells of the immune system
Definition
Macrophages, Natural Killer cells, Dendritic Cells, Complement, Lymphocyte, cytokines
Term
Major Histocompatibility Complex
Definition
set of molecules displayed on cell surfaces that are responsible for lymphocyte recognition and "antigen presentation"
Term
MHC class I
Definition
found on virtually every cell in the human body. Present to cytotoxic T-cells. Endogenous
Term
MHC class II
Definition
are only found on B-cells, macrophages and other "antigen-presenting cells". Present antigen to helper T-cells. Exogenous
Term
Macrophages
Definition
phagocytoses antigens, especially antigens coated by antibodiesd or complement proteins. Expresses class II MHC and serves as APC to CD4+ cells. Produces cytokines that activate lymphocytes or inflammatory action.
Term
Cytokines produced by macrophage.
Definition
Il-1, IL-6, IL-10, IL-12
Term
Percentage that Natural Killer cells account for peripheral blood lymphocytes.
Definition
10-15%
Term
Are Natural Killer Cells part of the innate or acquired immunity?
Definition
Innate
Term
T/F. Natural Killer cells are incapable of lysing a cell without having at least some previous sensitization
Definition
False. They are part of innate immune system and do no require previous sensitization
Term
Activating Receptor on NK cells
Definition
recognizes molecules on target cells
Term
Killer inhibitor receptor on NK cells
Definition
inhibits NK cytolysis by recognition of MHC I expression on target
Term
What cell expresses CD16 molecules and what does it do?
Definition
serves as a receptor for Fc receptor for IgG to attack antigen bound to IgG. Natural Killer cells
Term
Dendritic Cells
Definition
Main Function is to process antigen material and present it to other cells of the immune system thus functioning as APC
Term
Interdigitating Dendritic Cells
Definition
present in the epidermis, lymphoid tissues, and in the interstitum of nonlymphoid organs such as heart & lungs. Express high levels of class II MHC ideally suited for presenting antigens to CD4+
Term
Follicular Dendritic Cells
Definition
located in lymphoid follicles in the spleen and lymph nodes. Bind to antibodies via Fc receptors for IgG, resulting in trapping antigen bound to anntibodies. Present antigens to activated B lymphocytes.
Term
Are complements blood or serum proteins?
Definition
Serum
Term
What cells produce complements?
Definition
Macrophages & Hepatocytes which produce them initially as inactive molecules in circulation
Term
T/F. Complements are antigen specific and are activated only in the presence of antibodies.
Definition
False. Complements are not antigen specific and are activated immediately in the presence of pathogens(innate) or activated by antibodies(humoral immunity)
Term
Functions of Complements
Definition
stimulate inflammation, facilitate antigen phagocytosis and lyse some cells directly.
Term
Membrane Attack Complex (MAC)
Definition
formed at the end of activation of complement cascades to destroy lipid membrane of bacteria.
Term
Which complement proteins are responsible for chemotaxis?
Definition
C3a & C5a
Term
Which complement protein is responsible for enhancement of phagocytosis?
Definition
C3b
Term
Opsonization
Definition
Enhances phagocytosis. Makes the antigens "tastier" for the phagocytes.
Term
T/F. Vasoconstriction and increased permeability to proteins occurs as a result of the complement system?
Definition
False. Vasodilation occurs.
Term
Antigens or immunogens
Definition
any foreign substances that induce immune response. ex) protein coats of viruses, foreign proteins on foreign cells, cancer cells, transplanted cells, toxins
Term
3 stages of immune response
Definition
Recognition, Activation of lymphocytes, attacking on all antigens
Term
Recongnition of Antigen
Definition
lymphocyte binds with antigen, each lymphocyte specific for just one type of antigen. Progeny of this lymphocyte are clones.
Term
What is the number of distinct antigen receptors present in the lymphocyte population?
Definition
100 million
Term
Lymphocyte Activation
Definition
upon binind with antigen, lymphocyte divides many times called clonal expansion. some activated lymphocytes serve as effector lymphocytes. some serve as memory cells.
Term
Attacking on Antigens
Definition
launch an attack on all antigens of the kind that initiated the immune response. Upone successful mission, lymphocytes die through apoptosis. Memory cells however persist.
Term
Primary Lymphoid Organs
Definition
provide mature lymphocytes, bone marrow, thymus
Term
Secondary Lymphoid Organs
Definition
stores lymphocytes that are to be activated to participate immune responses. Lymph nodes, spleen, tonsils, GI, respiratory, genital, urinary tracts. Mature lymphocytes undergo additional cell divisions to produce more lymphocytes.
Term
T/F. Both B-cells and T-Cells are produced from the stem cells inthe bone marrow?
Definition
Trueskies
Term
B-Cells
Definition
produce antibodies against antigens and constitue humoral immunity
Term
Where are T-cells sensitized and what kind of immunity do they participate in?
Definition
They are sensitized at the they thymus and participate in cellular immunity.
Term
What percentage of circulating lymphocytes do T-cells represent?
Definition
60-70%
Term
What makes up a T-cell receptor?
Definition
alpha and Beta chains, which recognize and bind to antigens.
Term
What kind of MHC does CD4 bind to?
Definition
MHC class II, expressed on 60% of mature T cells.
Term
What is CD4?
Definition
T cell coreceptor that binds to MHC class II
Term
What is CD8?
Definition
T cell coreceptor that binds class I MHC and is expressed on 30% of mature T cells.
Term
CD4+ T cell
Definition
helper T cell & secretes cytokines, which activate B-cells and cytotoxic T cell.
Term
CD8+ T cell
Definition
Is cytotoxic T cell; role in directly killing virus-infected or tumor cells
Term
What percentage do B-cells represent of the circulating T-cells?
Definition
10-20%
Term
Are B-cells activated by CD4+ cells or CD8+ cells?
Definition
CD4+ cells
Term
What does an activated B-cell become?
Definition
Plasma cell which produces antibodies
Term
What is the order of Antibodies from highest concentration to least?
Definition
GAMDE
Term
T/F. B-Cell Receptors will recognize all antigens that it contacts.
Definition
False. BCR will recognize antigen with unique antigen specificity
Term
How do antibodies (Abs) inactivate antigens?
Definition
neutralizing microbes, oopsonizing microbes and facilitating phagocytosis, facilitating microbes being destroyed by NK cells, activating complements, which then destroy microbes.
Term
What are requirements for presenting antigens to a helper T cells?
Definition
Class II MHC: Macrophages, B cells, Dendritic Cells
Term
What are the requirements for presenting antigens to Cytotoxic Cells?
Definition
require class I MHC. Thus any cell can present to cytotoxic cells. Endogenous antigens from virus infected cells, cancer cells, attacked by cytotoxic T cells
Term
Activation of helper T cells
Definition
Presentation of antigen bound to APC expressing class II MHC.
Term
Which is higher in antibody production: first exposure to antigen or second exposure?
Definition
Second exposure
Term
Passive Immunity
Definition
Direct transusion of antibody from one person to another between ie)mother and child
Term
What are 3 ways cytokines induce effects?
Definition
Autocrine effect: act on cells from which a cytokine is produced. Paracrine: act on other cells in vicinity. Endocrine: systematic effect
Term
Pleiotropy
Definition
single cytokine can act on many cell types.
Term
Redundancy of cytokines
Definition
different cytokines can produce siilar effects
Term
What are the cytokines that mediate innate immunity?
Definition
Il-1, Il-12, TNF : mostly produced by activated Macrophages & Dendritic Cells
Term
Cytokines that regulate lymphocyte growth, activation and differentiation
Definition
IL-2, IL-4, IL-5, Interferon-gamma (IFN-gamma). most of these are produced by helper T cells
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