Inflammation, Tissue Repair, and Wound Healing (P) Flashcards
What is immunity?
It is the ability to resist harmful effects of microorganisms and other foreign substances
What are the 2 types of immunity?
1) Adaptive immunity
2) Innate immunity
What are the characteristics of adaptive immunity?
It exhibits:
1) Specificity and
2) Memory
What are the characteristics of innate immunity?
It does not show:
1) Specificity or
2) Memory
1) It responds quickly
Innate immunity consists of what?
1) Mechanical mechanisms
2) Chemical mediators and blood proteins (complement)
3) Cells
4) Inflammatory response
What are the exs of cells that are present in innate immunity?
1) Macrophages
2) Neutrophils
3) NK cells
What are the mechanical mechanisms that are present in innate immunity?
1) Skin and mucosae prevent entry of microorganisms
2) Tears, saliva, and mucus remove them
*What are the inflammation mediators (or chemical mediators) in innate immunity?
1) Histamine
2) Serotonin
3) Arachidonic acid metabolites
4) Cytokines (ILS / chemokines)
What are the diff cytokines?
1) Interferon alpha (IFNalpha[sign])
2) Interferon beta (IFNbeta[sign])
3) Interferon gamma (IFNgamma[sign])
4) Interleukin-1 (IL-1)
5) Interleukin-2 (IL-2)
6) Interleukin-4 (IL-4)
7) Interleukin-5 (IL-5)
8) Interleukin-8 (IL-8)
9) Interleukin-10 (IL-10)
10) Interleukin-15 (IL-15)
11) Lymphotoxin
12) Perforin
13) Tumor necrosis factor alpha(sign) (TNF[sign])
What are the functions of IFNalpha(sign)?
1) It prevents viral replication
2) It inhibits cell growth
What secretes IFNalpha(sign)?
It is secreted by virus-infected cells
What are the functions of IFNbeta(sign)?
1) It prevents viral replication
2) It inhibits cell growth
3) It decreases the expression of major histocompatibility complex (MHC) class I and II molecules
What secretes IFNbeta(sign)?
It is secreted by virus-infected fibroblasts
What is the characteristic of IFNgamma(sign)?
About 20 diff proteins that activate macrophages and natural killer (NK) cells
What are the functions of IFNgamma(sign)?
1) It stimulates adaptive immunity by increasing the expression of MHC class I and II molecules
2) It prevents viral replication
What secretes IFNgamma(sign)?
1) Helper T cells (Th cells)
2) Cytotoxic T cells (Tc cells)
3) NK cells
*What is IL-1?
It is the costimulation of B and T cells
What are the functions of IL-1?
1) It promotes inflammation through prostaglandin production
2) It induces fever acting through the hypothalamus (pyrogen)
What secretes IL-1?
1) Macrophages
2) B cells
3) Fibroblasts
*What is IL-2?
It is the costimulation of B and T cells
What are the functions of IL-2?
1) It activates macrophages
2) It activates NK cells
What secretes IL-2?
Helper T cells (Th cells)
What is the function IL -4?
It plays a role in allergic rxns by activation of B cells, resulting in the production of IgE
What secretes IL-4?
Helper T cells (Th cells)
What is the function of IL-5?
It is a part of the response against parasites by stimulating eosinophil production
What secretes IL-5?
Helper T cells (Th cells)
What is IL-8?
It is a chemotactic factor
What is the function of IL-8?
It promotes inflammation by attracting neutrophils and basophils
What secretes IL-8?
Macrophages
What are the functions of IL-10?
1) It inhibits the secretion of IFNgamma(sign)
2) It inhibits the secretion of ILs
What secretes IL-10?
Suppressor T cells
What are the functions of IL-15?
1) It promotes inflammation
2) It activates memory T cells
3) It activates NK cells
What is the function of lymphotoxin?
It kills target cells
What secretes lymphotoxin?
Cytotoxic T cells (Tc cells)
What is the function of perforin?
It makes a hole in the membrane of target cells
What is the result of the action done by perforin?
It results in the lysis of the cell
What secretes perforin?
Cytotoxic T cells (Tc cells)
What are the functions of TNFalpha(sign)?
1) It activates macrophages
2) It promotes fever (pyrogen)
What secretes TNFalpha(sign)?
Macrophages
Each complement pathway involves a what?
A cascade in w/c complement proteins are activated in an orderly sequence
*What are the end results when complement proteins are activated in an orderly sequence?
1) Cell lysis
2) Phagocytosis
3) Inflammation
What is complement?
It refers to a grp of 20 or so proteins that circulate in the blood in an inactive form
What are the functions of complement?
1) It provides a major mechanism for destroying foreign substances in the body
2) It amplifies all aspects of the inflammatory response
3) It kills bacteria and certain other cell types (our cells are immune to complement)
What pathways can activate complement?
Either:
1) Classical pathway or
2) Alternative pathway
Classical pathway is a part of what type of immunity?
Adaptive immunity
What is the characteristic of classical pathway?
It depends on the binding of Abs to invading organisms
What is the action present in classical pathway?
Subsequent binding of C1 to the Ag-Ab complexes (complement fixation)
Alternative pathway is a part of what type of immunity?
Innate immunity
What is the characteristic of alternative pathway?
It is triggered by the interaction among factors B, D, and P, and polysaccharide
What is the process (or steps) of classical pathway?
1) The classical pathway begins when an Ag-Ab complex binds to C1. The C1-Ag-Ab complex activates C4
2) Activated C4 forms a complex w/ C2 that activates C3
3) The alternate pathway begins when C3 is spontaneously activated
4) Foreign substances and factors B, D, and P stabilize activated C3
5) Once C3 is activated, the classical and alternate pathways are the same. C3 activates C5, C5 activates C6, C6 activates C7, C7 activates C8, and C8 activates C9
6) Activated C3-C7 promote phagocytosis, inflammation, and chemotaxis (attracts cells)
7) Activated C5-C9 combine to form a membrane attack complex (MAC), w/c forms a channel through the plasma membrane (only C9 of MAC is shown)
What are the IS cells that are present in innate immunity?
1) Neutrophil
2) Monocyte
3) Macrophage
4) Basophil
5) Mast cell
6) Eosinophil
7) NK cell
What are the primary functions of neutrophil?
1) Phagocytosis
2) Inflammation
3) Usually the first cell to leave the blood and enter infected tissues
What is the primary function of monocyte?
1) It leaves the blood and enters tissues to become a macrophage
What are the characteristics of macrophage?
1) It is the most effective phagocyte
2) It is located throughout the body to “intercept” foreign substances
What are the primary functions of macrophage?
1) It is important in later stages of infection and in tissue repair
2) It processes Ags
3) It is involved in the activation of B and T cells
What is the characteristic of basophil?
It is a motile cell
What are the functions of basophil?
It leaves the blood, enters tissues, and releases chemicals that promote inflammation
What is the characteristic of mast cell?
It is a nonmotile cell in connective tissues
What is the function of mast cell?
It promotes inflammation through the release of chemicals
What are the functions of eosinophil?
It enters tissues from the blood and releases chemicals that inhibit inflammation
What are the functions of NK cell?
1) It lyses tumor
2) It lyses virus-infected cells
What are the IS cells that are present in the adaptive immunity?
1) B cell
2) Plasma cell
3) Memory B cell
4) Cytotoxic T cell
5) Delayed hypersensitivity T cell
6) Helper T cell
7) Suppressor T cell
8) Memory T cell
9) Dendritic cell
What is the primary function of B cell?
After activation, it differentiates to become plasma cell or memory B cell
What is the primary function of plasma cell?
It produces Abs that are directly or indirectly responsible for the destruction of the Ag
What are the primary functions of memory B cell?
1) It is executes quick and effective response to an Ag against w/c the IS has previously reacted
2) It is responsible for immunity
What is the primary function of cytotoxic T cell?
It is responsible for the destruction of cells by lysis or by the production of cytokines
What is the primary function of delayed hypersensitivity T cell?
It produces cytokines that promote inflammation
What are the primary functions of helper T cell?
1) It activates B cells
2) It activates effector T cells
What are the primary functions of suppressor T cell?
1) It inhibits B cells
2) It inhibits effector T cells
What are the primary functions of memory T cell?
1) It executes quick and effective response to an Ag against w/c the IS has previously reacted
2) It is responsible for adaptive immunity
What are the primary functions of dendritic cells?
1) It processes Ag
2) It is involved in the activation of B and T cells
What are the diff ways of initiating an inflammatory response?
1) Chemical mediators cause vasodilation and increase vascular permeability, w/c allows the entry of other chemical mediators
2) Chemical mediators attract phagocytes
3) The amt of chemical mediators and phagocytes increases until the cause of the inflammation is destroyed. Then the tissue undergoes repair
What is inflammatory response?
It is a local inflammation that produces various symptoms
What are the symptoms being produced by inflammatory response?
1) Redness
2) Heat
3) Swelling
4) Pain
5) Loss of function
What are the symptoms of systemic inflammation?
1) An increase in neutrophil #s
2) Fever
3) Shock
What are the mediators of inflammation?
1) Histamines
2) Kinins
3) Prostaglandins
4) Leukotrienes
5) Others
What are the characteristics of mediators of inflammation?
1) These are produced in rapid bursts, only as long as the stimulus persists
2) They have short half-lives
3) They are degraded after their release
What is the characteristic of neutrophils?
They have short half-lives in tissues
What is the characteristic of inflammation?
It triggers a variety of stop signals that serve to actively terminate the rxn
*What are the mechanisms under inflammation in connection for it triggering a variety of stop signals that serve to actively terminate the rxn?
1) Switch in the type of arachidonic acid metabolite produced, from pro-inflammatory leukotrienes to anti-inflammatory lipoxins
2) Liberation of anti-inflammatory cytokines, including transforming growth factor-beta(sign) (TGF-beta[sign]) and IL-10, from macrophages and other cells
3) Production of anti-inflammatory lipid mediators, called resolvins and protectins, derived from polyunsaturated fatty acids
4) Neutral impulses (cholinergic discharge) that inhibit the production of TNF in macrophages
When does chronic inflammation occur?
It occurs when inflammation is prolonged or when there is interference to healing
Chronic inflammation results into what?
It results into replacement of normal tissue by a fibrous connective tissue = scarring
Provide an ex of chronic inflammation
Chronic granulomatous inflammation
What is the hallmark of chronic granulomatous inflammation?
*Presence of epitheloid cell
What is tissue repair?
It is the substitution of viable cells for dead cells
What are the mechanisms (or actions) present in tissue repair?
By regeneration or replacement
Tissue repair occurs depends on what?
1) Type of cell involved
2) Severity of the injury
3) Type of inflammation
*Cells (in tissue repair) are classified based on what?
Based on their ability to produce new cells
What are the 3 types of cells (in tissue repair) based on their ability to produce new cells?
1) Labile cells
2) Stable cells
3) Permanent cells
True or False
Generally, the more severe the injury is, the more likely replacement will take place
True
Tissue repair involves what?
1) Clot formation
2) Inflammation
3) Formation of granulation tissue
4) Regeneration or replacement of tissues
In severe wounds, what can occur?
Wound contracture
What is the simplified process (or steps) of healing and repair (of tissue)?
1) Injury
2) Hemostasis
- > PLTs
- > fibrin
- > fibronectin
- > transglutaminases
3) Inflammation
- > neutrophils
- > macrophages
- > lymphocytes
- > plasma proteins
4) Demolition
- > macrophages
- > collagenases
5) Proliferation
- > granulation tissue
- > anglogenesis
- > extracellular matrix synthesis
- > wound contraction
- > epithelial proliferation
6) Maturation
- > collagen crosslinking
- > remodeling
- > capillary resorption
What are the factors modifying the quality of the inflammatory-reparative response?
1) Adequacy of blood supply
2) Nutrition
3) Presence or absence of infection
4) Health status
5) Intake of drugs (e.g. steroids)
What are the functions of adaptive IS?
It is a functional system that:
1) Recognizes sp foreign substances
2) Acts to immobilize, neutralize, or destroy foreign substances
3) Amplifies inflammatory response and activates complement
What are the characteristics of adaptive IS?
1) It is Ag-specific
2) It is systemic
3) It has memory
What are the 2 separate but overlapping arms of adaptive IS?
1) Antibody-mediated (humoral) immunity
2) Cell-mediated immunity
Humoral immunity is provided by what?
It is provided by Abs in the blood and lymph
What are involved in cell-mediated immunity (CMI)?
Lymphocytes
What are Ags?
These are large molecules that stimulate an adaptive IS response
True or False
Foreign Ags are produced by the body
False, because foreign Ags are not produced by the body. Self-Ags are being produced by the body
What is the function of B cells?
They are responsible for Ab-mediated immunity
T cells are involved w/ what?
CMI
What are usually necessary to activate lymphocytes?
1) MHC Ag complex
2) Costimulation
Costimulation involves what?
1) Cytokines
2) Certain surface molecules
What is the action done by APCs?
They stimulate the proliferation of helper T cells
What is the action done by helper T cells?
They stimulate the proliferation of B or T effector cells
What is the characteristic of Abs?
These are proteins
*What are the actions that happen in Ab-mediated immunity?
1) The variable region of an Ab combines w/ the Ag
2) The constant region activates complement or binds to cells
What are the 5 classes of Abs?
1) IgG
2) IgM
3) IgA
4) IgE
5) IgD
What is the percentage of IgG in the total serum Ab?
80 - 85
What are the functions of IgG?
1) It activates complement
2) It promotes phagocytosis
3) It can cross the placenta and provide immune protection to the fetus and newborn
4) It is responsible for Rh rxns (such as hemolytic disease of the newborn)
What is the percentage of IgM in the total serum Ab?
5 - 10
What are the functions of IgM?
1) It activates complement
2) It acts as an Ag-binding receptor on the surface of B cells
3) It is responsible for transfusion rxns in the ABO blood system
What is the characteristic of IgM?
It is often the 1st Ab produced in response to an Ag
What is the percentage of IgA in the total serum Ab?
15
Where can IgA be found?
It can be secreted into:
1) Saliva
2) Tears
3) Mucous membranes
1) Colostrum
2) Milk
What is the function of IgA (in connection for it being secreted)?
To provide protection on body surfaces
What is the function of IgA (in connection for it being found in colostrum and milk)?
To provide immune protection to newborns
What is the percentage of IgE in the total serum Ab?
0.002
What are the functions of IgE?
1) It binds to mast cells
2) It binds to basophils
3) It stimulates the inflammatory response
What is the percentage of IgD in the total serum Ab?
0.2
What is the function of IgD?
It functions as Ag-binding receptors on B cells
True or False
Abs affect the Ag in many ways (in Ab-mediated immunity)
True
The primary response results from what (in connection to Ab production in Ab-mediated immunity)?
It results from the 1st exposure to an Ag
*In connection to primary response (in Ab-mediated immunity), B cells form what?
Plasma cells
What are the functions of plasma cells?
1) It produces Abs
2) It produces memory B cells
The secondary response results from what (in connection to Ab production in Ab-mediated immunity)?
It results from exposure to an Ag after a primary response
*In connection to secondary response (in Ab-mediated immunity), memory B cells quickly form what?
1) Plasma cells
2) Additional memory B cells
What are the actions present in CMI?
1) Cells infected w/ intracellular microorganisms process Ags that combine w/ MHC class I molecules
2) Cytotoxic T cells are stimulated to divide, producing more cytotoxic T cells and memory T cells, when MHC class I / Ag complexes are presented to T cell receptors
What is the function of cytokines in CMI?
1) Cytokines released from helper T cells also stimulate cytotoxic T cells
2) It promotes phagocytosis
3) It promotes inflammation
What are the function of cytotoxic T cells in CMI?
1) It lyses virus-infected cells
2) It lyses tumor cells
3) It lyses tissue transplants
What is the function of cytotoxic T cells in CMI?
It produces cytokines
Innate immunity, Ab-mediated immunity, and CMI can function together to what?
To eliminate an Ag
Provide the relationship (or concept diagram) of natural and artificial immunity
Natural; Artificial -> Active immunity -> Acquired adaptive immunity
Natural; Artificial -> Passive immunity -> Acquired adaptive immunity
What is natural immunity (in connection w/ active immunity)?
Ags are introduced through natural exposure
What is artificial immunity (in connection w/ active immunity)?
Ags are deliberately introduced in a vaccine
What is active immunity?
Immunity is provided by the individual’s own IS
What is natural immunity (in connection w/ passive immunity)?
Abs from the mother are transferred to her child across the placenta or in milk
What is artificial immunity (in connection w/ passive immunity)?
Abs are produced by another person or an animal are injected
What is passive immunity?
Immunity is transferred from another person or an animal
