Advanced Pathophysiology Exam 2

Infection Process Phase 4

4. Spread (Convalescence)—in most instances, the individual's immune and inflammatory systems successfully remove the infectious agent and symptoms decline; alternatively, the disease may be fatal or may enter a latency phase with resolution of symptoms until reactivation later.

What is colonal diversity?

1. Clonal diversity is when a large population of T cells and B cells is produced before birth. These lymphocytes have the capacity to recognize almost any foreign antigen found in the environment.

Infection Process Phase 1

1. Colonization (Incubation period) —the period from initial exposure to the infectious agent and the onset of the first symptoms, during which the microorganisms have entered the individual, undergone initial colonization, and begun multiplying, but are at insufficient numbers to cause symptoms; this period may last from several hours to years.

How is passive acquired immunity obtained?

1. Passive immunity is when performed antibodies or T lymphocytes are transferred from a donor to a recipient. Artificially acquired passive immunity is a short-term immunization by the injection of antibodies, such as gamma globulin, that are not produced by the recipient's cells. Naturally acquired passive immunity occurs during pregnancy, in which certain antibodies are passed from the maternal into the fetal bloodstream.

Systemic manifestations of inflammation

1. fever - caused by exogenous (pathogen produced) & endogenous (cytokines, IL-1) pyrogens and act directly on the hypothalamus. 2. Leukocytosis - increased numbers of circulating leukocytes, esp. neutrophils and "left shift" ratio of immature to mature neutrophils (increase in band cells). 3. Increased plasma protein synthesis -Acute-phase reactants and IL-1, C-reactive protein, fibrinogen, etc.

Infection Process Phase 2

2. Invasion (prodromal stage) —the occurrence of initial symptoms, which are often very mild and include a feeling of discomfort and tiredness.

Infection Process Phase 3

3. Multiplication (Invasion period) —the pathogen is multiplying rapidly, invading farther and affecting the tissues at the site of initial colonization as well as other areas; the immune and inflammatory responses have been triggered; symptoms may be specifically related to the pathogen or to the inflammatory response.

Cytotoxic T cells

A cytotoxic T cell (also known as TC, cytotoxic T lymphocyte, CTL, T-killer cell, cytolytic T cell, CD8+ T-cell or killer T cell) is a T lymphocyte (a type of white blood cell) that kills cancer cells, cells that are infected (particularly with viruses), or cells that are damaged in other ways.

Phagocytosis cells

A key component of the innate immune system. There are three main groups of phagocytes: monocytes and macrophages, granulocytes, and dendritic cells, all of which have a slightly different function in the body.

Acute Phase Response

A reaction that occurs when pyrogenic and other cytokines are released in response to infection and inflammation. In addition to fever, other symptoms occur including anorexia, fatigue, malaise, somnolence, and loss of concentration. At the cellular level, inflammatory pyrogenic cytokines promote muscle catabolism and hyperglycemia (gluconeogenesis, glycogenolysis, and insulin resistance) by stimulating release of adrenocorticotropic hormone and glucocorticoids to support glucoseconsuming cells.

Which statement is believed to be true concerning Th2 cells? a. Th2 cells are induced by antigens derived from allergens. b. They are induced by antigens derived from cancer cells. c. Th2 cells produce IL-2, TNF-ß, and IFN-γ. d. They assist in the development of cell-mediated immunity.

A. Antigens derived from multicellular parasites and allergens are hypothesized to be involved in the production of more Th2 cells. Th1 cells are induced by antigens derived from cancer cells. Th2 cells produce IL-4, IL-5, IL-6, and IL-13.

The healthcare professional working with older adults teaches general infection-prevention measures as a priority for this age group due to which change in lymphocyte function? a. Increased production of antibodies against self-antigens b. Decreased number of circulating T cells c. Decreased production of autoantibodies d. Increased production of helper T cells

A. B-cell function is altered with age as shown by decreases in specific antibody production in response to antigenic challenge, with concomitant increases in circulating immune complexes and in circulating autoantibodies (antibodies against self-antigens).

Which component of the plasma protein system tags pathogenic microorganisms for destruction by neutrophils and macrophages? a. Complement cascade b. Coagulation system c. Kinin system d. Immune system

A. C3b (a component of the complement cascade) adheres to the surface of a pathogenic microorganism and serves as an efficient opsonin. Opsonins are molecules that tag microorganisms for destruction by cells of the inflammatory system, primarily neutrophils and macrophages.

Which cell is the body's primary defense against parasite invasion? a. Eosinophil b. Neutrophils c. T lymphocytes d. B lymphocytes

A. Eosinophils serve as the body's primary defense against parasites. T lymphocytes and B lymphocytes are involved in acquired immunity. Neutrophils are the predominant phagocytes in the early inflammatory site

When mismatched blood is administered causing an ABO incompatibility, how are the erythrocytes destroyed? a. Complement-mediated cell lysis b. Phagocytosis by macrophages c. Phagocytosis in the spleen d. Natural killer cells

A. Erythrocytes are destroyed by complement-mediated lysis in individuals with autoimmune hemolytic anemia or as a result of an alloimmune reaction to ABO-mismatched transfused blood cells

Considering the hypothalamus, what is a fever produced by? a. Endogenous pyrogens acting directly on the hypothalamus b. Exogenous pyrogens acting directly on the hypothalamus c. Immune complexes acting indirectly on the hypothalamus d. Cytokines acting indirectly on the hypothalamus

A. Exogenous pyrogens indirectly affect the hypothalamus through the release of endogenous pyrogens by cells of the host, however; a number of cytokines have been identified as endogenous pyrogens and these act directly on the hypothalamus.

The generation of clonal diversity occurs primarily during which phase of life? a. Fetal b. Neonatal c. Infancy d. Puberty

A. Generation of clonal diversity primarily occurs in the fetus and probably continues to a low degree throughout most of adult life

A patient is having an IgE-mediated hypersensitivity reaction. What action by the healthcare professional is best? a. Give the patient an antihistamine. b. Prepare to give the patient a blood transfusion. c. Ask the patient is he/she is having pain at the site. d. Apply warm, moist heat to the affected area.

A. Histamine is the most potent mediator in an IgE-mediated hypersensitivity reaction (Type 1). Histamine bound to H2 results in the degranulation of mast cells with the release of histamine. Blocking histamine receptors with antihistamines can control some type I responses.

Immunoglobulin E (IgE) is associated with which type of hypersensitivity reaction? a. I b. II c. III d. IV

A. Hypersensitivity reactions have been divided into four distinct types: type I (IgE-mediated) hypersensitivity reactions, type II (tissue-specific) hypersensitivity reactions,

Which immunoglobulin is present in blood, saliva, breast milk, and respiratory secretions? a. IgA b. IgE c. IgG d. IgM

A. IgA can be divided into two subclasses, IgA1 and IgA2. IgA1 molecules are predominantly found in the blood, whereas IgA2 is the predominant class of antibody found in normal body secretions.

Phagocytosis involves neutrophils actively attacking, engulfing, and destroying which microorganisms? a. Bacteria b. Fungi c. Viruses d. Yeasts

A. Invasion is the direct confrontation with an individual's primary defense mechanisms against only bacteria, which include the complement system, antibodies, and phagocytes, such as neutrophils and macrophages. Fungi, viruses, and yeasts are not phagocytosed.

The functions of the major histocompatibility complex (MHC) and CD1 molecules are alike because both do what? a. Are antigen-presenting molecules b. Bind antigens to antibodies c. Secrete interleukins during the immune process d. Are capable of activating cytotoxic T lymphocytes

A. MHC and CD1 molecules are both antigen presenting molecules (APCs).

What is the function of opsonization related to the complement cascade? a. To tag pathogenic microorganisms for destruction by neutrophils and macrophages b. To process pathogenic microorganisms so that activated lymphocytes can be created for acquired immunity c. To destroy glycoprotein cell membranes of pathogenic microorganisms d. To promote anaphylatoxic activity, resulting in mast cell degranulation

A. Opsonins are molecules that tag microorganisms for destruction by cells of the inflammatory system (opsonization), primarily neutrophils and macrophages.

What type of immunity is produced when an immunoglobulin crosses the placenta? a. Passive-acquired immunity b. Active-acquired immunity c. Passive-innate immunity d. Active-innate immunity

A. Passive-acquired immunity (passive immunity) does not involve the host's immune response at all. Rather, passive immunity occurs when preformed antibodies or T lymphocytes are transferred from a donor to the recipient. This transfer can occur naturally, as in the passage of maternal antibodies across the placenta to the fetus, or artificially, as in a clinic using immunotherapy for a specific disease.

What occurs during the process of repair after tissue damage? a. Nonfunctioning scar tissue replaces destroyed tissue. b. Regeneration occurs; the original tissue is replaced. c. Resolution occurs; tissue is regenerated. d. Epithelialization replaces destroyed tissue.

A. Repair is the replacement of destroyed tissue with scar tissue. Regeneration is the replacement of damaged tissue with healthy tissue with complete return to normal structure and function. Resolution is synonymous with regeneration. Epithelialization is the process by which epithelial cells grow into the wound from surrounding healthy tissue.

The common hay fever allergy is expressed through a reaction that is mediated by which class of immunoglobulins? a. IgE b. IgG c. IgM d. T cells

A. Type I reactions are mediated by antigen-specific IgE and the products of tissue mast cells. The most common allergies (e.g., pollen allergies) are type I reactions. In addition, most type I reactions occur against environmental antigens and are therefore allergic.

Which statement is true concerning IgM? a. IgM is the first antibody produced during the initial response to an antigen. b. IgM mediates many common allergic responses. c. IgM is the most abundant class of immunoglobulins. d. IgM is capable of crossing the human placenta.

A. Typically, IgM is produced first (primary immune response), followed by IgG against the same antigen. IgE mediates allergic responses and is active in the defense against parasitic infections. IgG is the most abundant immunoglobulin class and can cross the human placenta to enter into fetal circulation

What is active immunity?

Active immunity is made by an individual after natural exposure to an antigen or after an immunization.

Hypersensitivity

An altered immunologic response to an antigen that results in disease or damage to the host. Hypersensitivity reactions can be classified in two ways: by the source of the antigen that the immune system is attacking (allergy, autoimmunity, alloimmunity) and by the mechanism that causes disease (types I, II, III, and IV).

What is an antibody?

An antibody/immunoglobulin is a blood protein made by plasma cells in response to and counteracting a specific antigen/immunogen. Antibodies combine chemically with substances which the body recognizes as alien, such as bacteria, viruses, and foreign substances in the blood.

What is the cause of transfusion reactions?

Antibodies in the recipient's blood can attack the donor blood if the two are not compatible. If the recipient's immune system attacks the red blood cells of the donor, it is called a hemolytic reaction. You can have an allergic reaction to a blood transfusion as well.

What are antigen-presenting cells (APCs)?

Antigen-presenting cells (APCs) are a heterogeneous group of immune cells that mediate the cellular immune response by processing and presenting antigens for recognition by certain lymphocytes such as T cells. Classical APCs include dendritic cells, macrophages, Langerhans cells and B cells.

What is an antigen?

Antigens are a foreign molecule that can react with binding sites on antibodies or antigen receptors on B and T cells. Most, but not all, antigens are also immunogens. An antigen that is immunogenic will induce an immune response, resulting in the production of antibodies or functional T cells. Thus, a substance may be antigenic yet not be immunogenic.

What organ does B lymphocytes originate from?

B cells develop from hematopoietic stem cells (HSCs) that originate from bone marrow B lymphocytes originate from the bone marrow. They live in the spleen, lymph nodes, adenoids, tonsils and Peyer patches after the are made.

What are blood transfusion reactions an example of? a. Autoimmunity b. Alloimmunity c. Homoimmunity d. Hypersensitivity

B. Alloimmunity (also termed isoimmunity) occurs when the immune system of one individual produces an immunologic reaction against tissues of another individual. Autoimmunity is a disturbance in the immunologic tolerance of self-antigens. Homoimmunity refers to the resistance of a lysogenic bacterium that is carrying a phage to an infection by the same type of phage. Hypersensitivity is an altered immunologic response to an antigen that results in disease or damage to the host.

Type III hypersensitivity reactions are a result of which of these? a. Antibodies coating mast cells by binding to receptors that signal its degranulation, followed by the discharge of preformed mediators b. Antibodies binding to soluble antigens that were released into body fluids and the immune complexes being deposited in the tissues c. Tc cells or lymphokine-producing Th1 cells directly attacking and destroying cellular targets d. Antibodies binding to the antigen on the cell surface

B. Antigen-antibody (immune) complexes that are formed in the circulation and then deposited later in vessel walls or extravascular tissues cause most type III hypersensitivity diseases. Type III hypersensitivity reactions are not the result of antibodies coating mast cells to signal their degranulation, immune cells directly attacking and destroying targets, or antibodies binding to the antigen on the cell surface.

Which statement is believed to be true concerning Th1 cells? a. Th1 cells are induced by antigens derived from allergens. b. They are induced by antigens derived from cancer cells. c. Th1 cells produce IL-4, IL-5, IL-6, and IL-13. d. They assist in the development of humoral immunity.

B. Antigens derived from viral or bacterial pathogens and those derived from cancer cells are hypothesized to induce a greater number of Th1 cells relative to Th2 cells.

Evaluation of umbilical cord blood can confirm that which immunoglobulin level is near adult levels? a. IgA b. IgG c. IgM d. IgE

B. At birth, the total IgG level in the umbilical cord is the only immunoglobulin that is near adult levels. This is due to a system of active transport that facilitates the passage of maternal antibodies into the fetal circulation.

In regulating vascular mediators released from mast cells, the role of eosinophils is to release what? a. Arylsulfatase B, which stimulates the formation of B lymphocytes b. Histaminase, which limits the effects of histamine during acute inflammation c. Lysosomal enzymes, which activate mast cell degranulation during acute inflammation d. Immunoglobulin E, which defends the body against parasites

B. Eosinophil lysosomes contain several enzymes that degrade vasoactive molecules, thereby controlling the vascular effects of inflammation. These enzymes include histaminase, which mediates the degradation of histamine, and arylsulfatase B, which mediates the degradation of some of the lipid-derived mediators produced by mast cells.

What is a hypersensitivity reaction that produces an allergic response called? a. Hemolytic shock b. Anaphylaxis c. Necrotizing vasculitis d. Systemic erythematosus

B. Examples of systemic anaphylaxis are allergic reactions to beestings, peanuts, and fish. Hemolytic shock would be a state in which erythrocytes are destroyed by complement-mediated lysis to the point of causing a state of shock. Necrotizing vasculitis is inflammation of blood vessel walls that limits perfusion. Systemic lupus erythematosus (SLE) is a chronic, multisystem, inflammatory disease and is one of the most common, complex, and serious of the autoimmune disorders.

Which characteristic is the most important determinant of immunogenicity when considering the antigen? a. Size b. Foreignness c. Complexity d. Quantity

B. Foremost among the criteria for immunogenicity is the antigen's foreignness. A self-antigen that fulfills all of these criteria except foreignness does not normally elicit an immune response. Thus most individuals are tolerant of their own antigens. The immune system has an exquisite ability to distinguish self (self-antigens) from nonself (foreign antigens).

What is the first stage in the infectious process? a. Invasion b. Colonization c. Spread d. Multiplication

B. From the perspective of the microorganisms that cause disease, the infectious process undergoes four separate stages of progression: (1) colonization, (2) invasion, (3) multiplication, and (4) spread.

What does the student learn about HIV? a. HIV only infects T-helper (Th) cells. b. HIV is a retrovirus. c. HIV carries genetic information in its DNA. d. HIV has five identified strains.

B. HIV is a member of the retrovirus family, which carries genetic information in the form of two copies of RNA. The major immunologic finding in AIDS is the striking decrease in the number of CD4+ Th cells. The major surface receptor on the HIV virus binds to the CD4 molecule found mostly on the surface of T-helper cells. There appear to be two strains of HIV: HIV-1 and HIV-2.

What are vaccines against viruses created from? a. Killed organisms or extracts of antigens b. Live organisms weakened to produce antigens c. Purified toxins that have been chemically detoxified d. Recombinant pathogenic protein

B. Most vaccines against viral infections (e.g., measles, mumps, rubella, varicella [chickenpox], rotavirus) contain live viruses that are weakened (attenuated) to continue expressing the appropriate antigens but are unable to establish more than a limited and easily controlled infection.

Which is an example of an endogenous antigen? a. Yeast b. Cancer cells c. Bacteria d. Fungus

B. Of the options provided, endogenous antigens include only those uniquely produced by cancerous cells.

In the later stages of an inflammatory response, which phagocytic cell is predominant? a. Neutrophils b. Monocytes c. Chemokines d. Eosinophils

B. Only monocytes and macrophages perform many of the same functions as neutrophils but for a longer time and in a later stage of the inflammatory response.

What plasma protein system forms a fibrinous meshwork at an inflamed site? a. Complement b. Coagulation c. Kinin d. Fibrinolysis

B. The coagulation (clotting) system is a group of plasma proteins that form a fibrinous meshwork at an injured or inflamed site. This protein system (1) prevents the spread of infection to adjacent tissues, (2) traps microorganisms and foreign bodies at the site of inflammation for removal by infiltrating cells (e.g., neutrophils and macrophages), (3) forms a clot that stops the bleeding, and (4) provides a framework for future repair and healing.

What causes the edema that occurs during the inflammatory process? a. Vasodilation of blood vessels b. Increased capillary permeability c. Endothelial cell expansion d. Emigration of neutrophils

B. The increased flow and capillary permeability result in a leakage of plasma from the vessels, causing swelling (edema) in the surrounding tissue and is solely responsible for inflammation-induced edema. Vasodilation (increased size of the blood vessels) causes slower blood velocity and increases blood flow to the injured site. Endothelial cell contraction (not expansion) leads to increased capillary permeability. Emigration of neutrophils to the area of infection/injury leads to increased destruction of the offending agent.

What is a role of a natural killer (NK) cells? a. Initiation of the complement cascade b. Elimination of malignant cells c. Binding tightly to antigens d. Proliferation after immunization with antigen

B. The main function of NK cells is to recognize and eliminate cells infected with viruses, although they are also somewhat effective at eliminating other abnormal host cells, specifically cancer cells. The complement system is activated in one of three ways (classical, lectin, and alternative), none of which involve NK cells. Antibodies bind tightly to antigens. Immunization leads to the proliferation of antibodies.

Which manifestation of inflammation is systemic? a. Formation of exudates b. Fever and leukocytosis c. Redness and heat d. Pain and edema

B. The only three primary systemic changes associated with the acute inflammatory response are fever, leukocytosis (a transient increase in circulating leukocytes), and increased levels in circulating plasma proteins. Exudate, redness, heat, pain, and edema are local signs.

Which antibody initially indicates a typical primary immune response? a. IgG b. IgM c. IgA d. IgE

B. Typically, IgM is produced first (primary immune response), followed by IgG against the same antigen. IgA and IgE are not involved in the typical primary immune response.

Vaccinations are able to provide protection against certain microorganisms because of what? a. Strong response from IgM b. Level of protection provided by IgG c. Memory cells for IgE d. Rapid response from IgA

B. Vaccinations provide protection by a secondary response when the individual is exposed to the microorganism to which he or she was vaccinated. At that time, IgG production is considerably increased, making it the predominant antibody class of the secondary response. IgM is more active against the primary exposure. IgE is usually seen in allergies. IgA is the predominant secretory antibody and prevents the attachment and invasion of pathogens through mucosal membranes.

A keloid is the result of which dysfunctional wound healing response? a. Epithelialization b. Contraction c. Collagen matrix assembly d. Maturation

C An imbalance between collagen synthesis and collagen degradation, during which synthesis is increased relative to degradation, causes both keloids and hypertrophic scars.

Where are antibodies produced? a. Helper T lymphocytes b. Thymus gland c. Plasma cells d. Bone marrow

C. An antibody or immunoglobulin is a serum glycoprotein produced only by plasma cells in response to a challenge by an immunogen.

Which cell has the ability to recognize antigens presented by the MHC class I molecules? a. T cytotoxic b. CD 4 c. CD 8 d. T helper

C. CD8 cells recognize antigens presented by the major histocompatibility complex (MHC) class I molecules and become mediators of cell-mediated immunity and directly kill other cells (T-cytotoxic cells). CD4 cells tend to recognize antigen presented by MHC class II molecules and develop into helpers in the later clonal selection process (T-helper cells).

In a type III hypersensitivity reaction, the harmful effects after the immune complexes that are deposited in tissues are a result of what? a. Cytotoxic T cells b. Natural killer cells c. Complement activation d. Degranulation of mast cells

C. Complement activation, particularly through the generation of chemotactic factors for neutrophils, causes the harmful effects of immune complex deposition. The neutrophils bind to antibody and C3b contained in the complexes and attempt to ingest the immune complexes.

What is the role of fibroblasts during the reconstructive phase of wound healing? a. Generate new capillaries from vascular endothelial cells around the wound. b. Establish connections between neighboring cells and contract their fibers. c. Synthesize and secrete collagen and the connective tissue proteins. d. Provide enzymes that débride the wound bed of dead cells.

C. Fibroblasts are the most important cells during the reconstructive phase of wound healing because they synthesize and secrete collagen and other connective tissue proteins. Macrophage-derived transforming growth factor-beta (TGF-ß) stimulates fibroblasts. Fibroblasts do not generate new capillaries, establish connections between neighboring cells, or provide enzymes to debride the wound bed.

What is the vascular effect of histamine released from mast cells? a. Platelet adhesion b. Initiation of the clotting cascade c. Vasodilation d. Increased endothelial adhesiveness

C. Histamine, when released from mast cells, causes vasodilation.

How is hypersensitivity best defined? a. A disturbance in the immunologic tolerance of self-antigens b. An immunologic reaction of one person to the tissue of another person c. An altered immunologic response to an antigen that results in disease d. An undetectable immune response in the presence of antigens

C. Hypersensitivity is an altered immunologic response to an antigen that results in disease or damage to the host. Autoimmunity is a disturbance in the immunologic tolerance of self-antigens. Alloimmunity is the immunologic reaction of one person to the tissue of another person. An immune deficiency of some type would cause undetectable immune response in the presence of antigens.

Which action is a purpose of the inflammatory process? a. To provide specific responses toward antigens b. To lyse cell membranes of microorganisms c. To prevent infection of the injured tissue d. To create immunity against subsequent tissue injury

C. If the epithelial barrier is damaged, then a highly efficient local and systemic response (inflammation) is mobilized to limit the extent of damage, to protect against infection, and to initiate the repair of damaged tissue. The response to a specific offending agent is the function of the adaptive immune response. Lysosomes lyse cell membranes. Immunity against a subsequent tissue injury occurs through the action of B cells and T cells.

A healthcare professional is conducting community education on vaccinations. Which statement about vaccines does the professional include in the presentation? a. Most bacterial vaccines contain attenuated organisms. b. Most viral vaccines are made by using dead organisms. c. Vaccines require booster injections to maintain life-long protection. d. Vaccines provide effective protection against most infections.

C. In general, vaccine-induced protection does not persist as long as infection-induced immunity, thus booster injections may be necessary to maintain protection throughout the life. Some common bacterial vaccines are killed microorganisms, extracts of bacterial antigens, or toxoids

Some older adults have impaired inflammation and wound healing because of which problem? a. Circulatory system cannot adequately perfuse tissues. b. Complement and chemotaxis are deficient. c. Underlying chronic illness(es) exists. d. Number of mast cells is insufficient.

C. In some cases, impaired healing is not directly associated with aging, in general, but can instead be linked to a chronic illness such as cardiovascular disease or diabetes mellitus.

Once they have penetrated the first line of defense, which microorganisms do natural killer (NK) cells actively attack? a. Bacteria b. Fungi c. Viruses d. Mycoplasma

C. NK cells are the principal defenders against only tumor cells or virally infected cells

A student is preparing to irrigate a patient's wound and gathers supplies, including hydrogen peroxide. What response by the health care professional is best? a. Help the student gather the rest of the supplies. b. Instruct the student to dilute the hydrogen peroxide. c. Tell the student to get some normal saline instead. d. Ask the patient if pain medication is needed first.

C. Normal saline is the most innocuous solution that can be used to cleanse or irrigate a wound that is primarily healing by epithelialization. The professional should instruct the student to use it instead of the peroxide to avoid tissue damage. Helping to gather supplies, diluting the solution, or medicating the patient for pain will not avoid the tissue damage that will be caused by the hydrogen peroxide.

During an IgE-mediated hypersensitivity reaction, which leukocyte is activated? a. Neutrophils b. Monocytes c. Eosinophils d. T lymphocytes

C. Of the options provided, only eosinophils are activated during IgE-mediated hypersensitivity reactions.

What is the correct sequence in phagocytosis? a. Engulfment, recognition, fusion, destruction b. Fusion, engulfment, recognition, destruction c. Recognition, engulfment, fusion, destruction d. Engulfment, fusion, recognition, destruction

C. Once the phagocytic cell enters the inflammatory site, the only correct sequence of phagocytosis involves the following steps: (1) opsonization, or recognition, of the target and adherence of the phagocyte to it; (2) engulfment, or ingestion or endocytosis, and the formation of phagosome; (3) fusion with lysosomal granules within the phagocyte (phagolysosome); and (4) destruction of the target.

When considering white blood cell differentials, acute inflammatory reactions are related to elevations of which leukocyte? a. Monocytes b. Eosinophils c. Neutrophils d. Basophils

C. Only neutrophils are the predominant phagocytes in the early inflammatory site, arriving within 6 to 12 hours after the initial injury, they ingest (phagocytose) bacteria, dead cells, and cellular debris at the inflammatory site.

A student asks the healthcare professional how the aging process of the T-cell activity affects older adults. What response by the professional is best? a. Poor heat regulation abilities b. Increased risk for bone fractures c. Tendency to develop various infections d. Likelihood of experiencing benign skin lesions

C. T-cell activity is deficient in older adults, and a shift in the balance of T-cell subsets is observed. These changes may result in increased susceptibility to infection

Th2 cells produce IL-4 and suppress which cells? a. B lymphocytes b. Cytotoxic T lymphocytes c. Th1 cells d. Memory T lymphocytes

C. Th2 cells produce IL-4, which suppresses only Th1 and Th17 cells through their IL-4 receptors.

Tissue damage caused by the deposition of circulating immune complexes containing an antibody against the host DNA is the cause of which disease? a. Hemolytic anemia b. Pernicious anemia c. Systemic lupus erythematosus d. Myasthenia gravis

C. The deposition of circulating immune complexes containing an antibody against the host DNA produces tissue damage in individuals with systemic lupus erythematosus (SLE).

A student is confused about the process of the generation of clonal diversity. What description by the professor is best? a. It involves antigens that select those lymphocytes with compatible receptors. b. It allows the differentiation of cells into antibody-secreting plasma cells or mature Peyer patches. c. It takes place in the primary (central) lymphoid organs. d. It causes antigens to expand and diversify their populations.

C. This process occurs in central lymphoid organs—the thymus gland for T cells and bone marrow for B cells.

How does the chemotactic factor affect the inflammatory process? a. By causing vasodilation around the inflamed area b. By stimulating smooth muscle contraction in the inflamed area c. By directing leukocytes to the inflamed area d. By producing edema around the inflamed area

C. Two chemotactic factors, neutrophil chemotactic factor (NCF) and eosinophil chemotactic factor of anaphylaxis (ECF-A), are released during mast cell degranulation. NCF attracts neutrophils (a type of leukocytes), and ECF-A attracts eosinophils to the site of inflammation.

A type IV hypersensitivity reaction causes which result? a. Antibodies coating mast cells by binding to receptors that signal its degranulation, followed by the discharge of preformed mediators b. Antibodies binding to soluble antigens that were released into body fluids and the immune complexes being deposited in the tissues c. Lymphokine-producing Th1 cells directly attacking and destroying cellular targets d. Antibodies binding to the antigen on the cell surface

C. Type I, II, and III hypersensitivity reactions are mediated by antibody, type IV reactions are mediated by T lymphocytes and do not involve antibody. Type IV mechanisms occur through either Tc cells or lymphokine-producing Th1 cells. Tc cells directly attack and destroy cellular targets.

CD4 cells

CD4 cells are white blood cells that play an important role in the immune system. Your CD4 cell count gives you an indication of the health of your immune system - your body's natural defense system against pathogens, infections and illnesses. CD4 cells are sometimes also called T-cells, T-lymphocytes, or helper cells.

CD8+ cytotoxic T cells

CD8+ (cytotoxic) T cells, like CD4+ Helper T cells, are generated in the thymus and express the T-cell receptor. However, rather than the CD4 molecule, cytotoxic T cells express a dimeric co-receptor, CD8, usually composed of one CD8α and one CD8β chain.

What is cell-mediated immunity?

Cellular immunity is when T cells are found in the blood, tissues and organs and defend against intracellular pathogens (e.g., some viruses) and cancer cells. T cells may produce cytokines that stimulate the protective response of other leukocytes. Others develop into Tc cells that attack and kill cellular targets directly.

What are class I and class II MHC complex?

Class I MHC molecules have β2 microglobulin subunit which can only be recognised by CD8 co-receptors. Class II MHC molecules have β1 and β2 subunits and can be recognised by CD4 co-receptors.

What is colonal selection?

Clonal selection's purpose is to select, expand, and differentiate clones of T and B cells against a specific antigen. Clonal selection theory of lymphocytes: 1) A hematopoietic stem cell undergoes differentiation and genetic rearrangement to produce 2) immature lymphocytes with many different antigen receptors

When a person is exposed to most antigens, antibodies can be usually detected in their circulation within what timeframe? a. 12 hours b. 24 hours c. 3 days d. 6 days

D. After approximately 5 to 7 days is an IgM antibody specific for that antigen detected in the circulation

Antibodies that are associated with mucosal immune system, such as immunoglobulins, function to prevent which type of infections? a. Infections that attack the respiratory system b. Infections that tend to be chronic in nature c. Infections likely to be resistant to antibiotics d. Infections that focus on epithelial surfaces of the body

D. Antibodies of the systemic immune system function throughout the body, whereas antibodies of the secretory (mucosal) immune system—primarily immunoglobulins of the IgA class—are associated with bodily secretions and function to prevent pathogenic infection on epithelial surfaces.

Cytokines are vital to a cell's ability to do which function? a. Excrete b. Reproduce c. Metabolize d. Communicate

D. During their interactions, cells must communicate with each other through soluble cytokines. The other options are not so rigidly related to cytokines.

A student asks why some vaccinations are given orally and some are given by injection. What response by the professor is best? a. Different routes allow the speed of onset of the antigen to be varied, with the intravenous route being the fastest. b. Some individuals appear to be unable to respond to an antigen by a specific route, thus requiring the availability of different routes for the same antigen. c. Antigen-presenting cells are highly specialized and thus require stimulation by different routes. d. Each route stimulates a different lymphocyte-containing tissue, resulting in different types of cellular and humoral immunity.

D. Each route preferentially stimulates a different set of lymphocyte-containing (lymphoid) tissues and therefore results in the induction of different types of cell-mediated or humoral immune responses.

What is the role of reverse transcriptase in HIV infection? a. Reverse transcriptase converts single-stranded DNA into double-stranded DNA. b. It is needed to produce integrase. c. It transports the RNA into the cell nucleus. d. It converts RNA into double-stranded DNA.

D. HIV is a retrovirus and carries an enzyme, reverse transcriptase, which creates a double-stranded DNA version of the virus. HIV virus does not contain DNA. Reverse transcriptase does not transport the RNA into the cell nucleus

What is an outcome of the complement cascade? a. Activation of the clotting cascade b. Prevention of the spread of infection to adjacent tissues c. Inactivation of chemical mediators such as histamine d. Lysis of bacterial cell membranes

D. The complement cascade can be activated by at least three different means, and its products have four functions: (1) anaphylatoxic activity, resulting in mast cell degranulation, (2) leukocyte chemotaxis, (3) opsonization, and (4) cell lysis.

A student asks about the mechanism that results in type II hypersensitivity reactions. What description by the professor is best? a. Antibodies coat mast cells by binding to receptors that signal its degranulation, followed by a discharge of preformed mediators. b. Antibodies bind to soluble antigens that were released into body fluids, and the immune complexes are then deposited in the tissues. c. Cytotoxic T lymphocytes or lymphokine-producing helper T 1 cells directly attack and destroy cellular targets. d. Antibodies bind to the antigens on the cell surface.

D. The mechanism that results in a type II hypersensitivity reaction begins with antibody binding to tissue-specific antigens or antigens that have attached to particular tissues. The cell can be destroyed by antibody IgG or IgM and activation of the complement cascade through the classical pathway.

How are target cells destroyed in a type II hypersensitivity reaction? a. Tissue damage from mast cell degranulation b. Antigen-antibody complexes deposited in vessel walls c. Cytotoxic T lymphocytes attack the cell directly. d. Natural killer cells

D. The mechanism that results in a type II hypersensitivity reaction involves a subpopulation of cytotoxic cells that are not antigen specific (natural killer [NK] cells). Antibody on the target cell is recognized by Fc receptors on the NK cells, which releases toxic substances that destroy the target cell. Tissue damage from mast cell degranulation occurs in type I hypersensitivity reactions. Antigen-antibody complexes are active in type III hypersensitivity responses. Cytotoxic lymphocytes are involved in type IV hypersensitivity responses.

A person with type O blood needs a blood transfusion. What blood type does the healthcare professional prepare to administer to the patient? a. A b. B c. AB d. O

D. Type O individuals have neither A or B antigen but have both anti-A and anti-B antibodies and therefore cannot accept blood from any of the other three types. The healthcare professional would prepare to administer a transfusion of type O blood

Urticaria is a manifestation of a which type of hypersensitivity reaction? a. IV b. III c. II d. I

D. Urticaria, or hives, is a dermal (skin) manifestation of only type I allergic reactions

Dehiscence and Evisceration

Dehiscence - wound pulls apart at the suture line, excessive strain, tension, obesity are causes, increases risk of wound sepsis. Evisceration - bowel contents protruding through the abdominal wall.

What is the difference between active immunity and passive immunity?

Difference between active immunity and passive immunity is that active immunity is being produced for the contact with pathogen or the antigen, whereas passive immunity is being produced for the antibodies that are obtained from outside.

What is happening during opsonization?

During opsonization opsonin binds to a pathogen, then phagocytes are attracted, and the pathogen is opsonized (destroyed). It is bound with the antibody IgG.

Exudative fluids

Exudate varies in composition, depending on the stage of the inflammatory response and, to some extent, the injurious stimulus. In early or mild inflammation, the exudate is watery (serous) with very few plasma proteins or leukocytes. An example of serous exudate is the fluid in a blister. In more severe or advanced inflammation, the exudate may be thick and clotted (fibrinous exudate), such as in the lungs of individuals with pneumonia. If many leukocytes accumulate, as in persistent bacterial infections, the exudate consists of pus and is called a purulent (suppurative) exudate. Purulent exudate is characteristic of walled-off lesions (cysts or abscesses). If bleeding occurs, the exudate is filled with erythrocytes and is described as a hemorrhagic exudate.

How many stages of the infection process?

Four

How many types of hypersensitivities?

Four

What is humoral immunity?

Humoral immunity has antibodies and T cells. Antibody circulates in the blood and in secretions and defends against pathogens that are found. The pathogen will then be directly inactivated or activation of an inflammatory mediator (e.g., complement, phagocytes) that will destroy the pathogen. Antibody is primarily responsible for protection against many bacteria and viruses.

IgA

IgA can be divided into two subclasses, IgA1 and IgA2. IgA1 molecules are found predominantly in the blood, whereas IgA2 is the predominant class of antibody found in normal body secretions

IgD

IgD is limited. This class of immunoglobulins is found in very low concentrations in the blood. IgD functions as an antigen receptor on the surface of early B lymphocytes.

IgE

IgE is normally at low concentrations in the circulation. It functions as a mediator of many common allergic responses and in the defense against parasitic infections.

IgG

IgG is the most abundant class of immunoglobulins, constituting 80% to 85% of those circulating in the body and accounting for most of the protective activity against infections

IgM

IgM is the largest of the immunoglobulins and usually exists as a pentamer. It is the first antibody produced during the initial, or primary, response to antigen. IgM is usually synthesized early in neonatal life, but may be increased as a response to infection in utero.

Type I Hypersensitivity

In type 1, the antigen, which is usually external allergens such as pollens or certain food molecules, binds to IgE antibodies attached to the surface of mast cells or basophils. This antigen-antibody binding induces cascade of intracellular reactions resulted in release of large amount of histamine from the storage vesicles. The released histamine induces various degrees of allergic reactions.

Live viruses attenuated vaccines

Live viruses that are weakened (attenuated) to continue expressing the appropriate antigens but are unable to establish more than a limited and easily controlled infection.

What is Major histocompatibility complex (MHC)?

MHC molecules are glycoproteins found on the surface of all human cells except red blood cells. They are divided into two general classes, class I and class II, based on their molecular structure, distribution among cell populations, and function in antigen presentation.

What are neutrophils role in the inflammatory phase?

Neutrophils and macrophages clear the wound of debris (fibrin from dissolved clots, microorganisms, erythrocytes, and dead tissue cells). This cleanup of the lesion, which also involves dissolution of fibrin clots (or scabs) by fibrinolytic enzymes, is called débridement. After débridement the remaining debris is drained away by blood vessels and lymphatics, and the vascular dilation and permeability associated with inflammation are reversed, thus preparing the lesion for either regeneration or repair.

What is passive immunity?

Passive immunity is when performed antibodies or T lymphocytes are transferred from a donor to a recipient. For example, in the passage of maternal antibodies across the placenta to the fetus, or artificially, as in a clinic using immunotherapy for a specific disease. Unvaccinated people who are exposed to particular infectious agents (e.g., hepatitis A virus, rabies virus) often will be given immunoglobulins that are prepared from individuals who already have antibodies against that particular pathogen. Passive immunity is only temporary because the donor's antibodies or T cells are eventually destroyed.

Describe the differences between primary immune response and secondary immune response

Primary immune response is mainly in the lymph nodes and spleen. Secondary response appears mainly in the bone marrow, followed by the spleen and lymph nodes. Both Thymus dependent and Thymus independent antigen gives primary immune response. Antigen‐specific T cells are selected during a primary immune response and expand to produce clones of T cells with high specificity for the activating antigen. ... In a secondary response to the same antigen, memory cells are rapidly activated. This process is quicker and more effective than the primary response. Antibodies have greater affinity for antigen.

Three roles of T cells

T cells play a major role in defense against intracellular pathogens such as viruses, protozoa and intracellular bacteria, and in immunity to extracellular pathogens by providing help for the antibody response. T cell, also called T lymphocyte, type of leukocyte that is an essential part of the immune system. T cells are one of two primary types of lymphocytes—B cells being the second type—that determine the specificity of immune response to antigens (foreign substances) in the body.

The inflammatory phase

The inflammatory phase includes coagulation and the infiltration of cells that participate in wound healing, including platelets, neutrophils, and macrophages. The fibrin mesh of the blood clot acts as a scaffold for cells that participate in healing. Platelets contribute to clot formation and, as they degranulate, release growth factors that initiate proliferation of undamaged cells. Neutrophils and macrophages clear the wound of debris (fibrin from dissolved clots, microorganisms, erythrocytes, and dead tissue cells). This cleanup of the lesion, which also involves dissolution of fibrin clots (or scabs) by fibrinolytic enzymes, is called débridement. After débridement the remaining debris is drained away by blood vessels and lymphatics, and the vascular dilation and permeability associated with inflammation are reversed, thus preparing the lesion for either regeneration or repair.

What contributes to immunogenicity and how to assess what would be most immunogenic

The nature of the Immunogen. Foreignness. Molecular size. Chemical composition and heterogeneity contribute to immunogenicity. Ability to be processed and presented with an MHC molecule on the surface of Antigen Presenting Cells (APCs) or altered self-cell.

What are primary and secondary responses?

The primary immune response occurs when an antigen comes in contact to the immune system for the first time. The secondary immune response occurs when the second time (3rd, 4th, etc.) the person is exposed to the same antigen

Regulatory T cells (Treg)

The regulatory T cells, formerly known as suppressor T cells, are a subpopulation of T cells that modulate the immune system, maintain tolerance to self-antigens, and prevent autoimmune disease.

The secondary intention of wound healing

The secondary intention of wound healing is secondary closure/healing - describes the healing of a wound in which the wound edges cannot be approximated. Secondary closure requires a granulation tissue matrix to be built to fill the wound defect. o In this type of wound, there is a loss of skin, and granulation tissue fills the area left open. Healing is slow, which places the patient at risk for infection. Examples of wounds healing by secondary intention include severe lacerations or massive surgical interventions. o With proper care, this process can take anywhere from 6-8 weeks for healing to occur depending on the size of your wound. There are several important steps necessary to insure proper healing.

Th1/Th2 cells

Type 1 T helper (Th1) cells produce interferon-gamma, interleukin (IL)-2, and tumour necrosis factor (TNF)-beta, which activate macrophages and are responsible for cell-mediated immunity and phagocyte-dependent protective responses.

Type II Hypersensitivity

Type II (tissue-specific) hypersensitivity reactions are generally characterized by a specific cell or tissue being the target of an immune response. Binding of IgG or IgM antibodies stimulate cascade of immune reactions result in activations of complement system, natural killers, and macrophages. Which induce further damage to affected tissues..

Type III Hypersensitivity

Type III (immune complex-mediated) hypersensitivity reactions are caused by antigen-antibody (immune) complexes that are formed in the circulation and deposited later in vessel walls or extravascular tissues. in type III the antibody binds to soluble antigen that was released into the blood or body fluids, and the complex is then deposited in the tissues. Type III reactions are not organ specific, and symptoms have little to do with the particular antigenic target of the antibody.

Type IV Hypersensitivity

Type IV (cell-mediated) hypersensitivity reactions are mediated by T lymphocytes and do not involve antibody (Fig. 9.4). Type IV mechanisms occur through either cytotoxic T lymphocytes (Tc cells) or lymphokine-producing Th1 and Th17 cells. Tc cells attack and destroy cellular targets directly. Th1 and Th17 cells produce cytokines that recruit and activate phagocytic cells, especially macrophages. Destruction of the tissue is usually caused by direct killing by toxins from Tc cells or by the release of soluble factors, such as lysosomal enzymes and toxic reactive oxygen species (ROS), from activated macrophages

Full thickness wound healing

Wound healing involves processes that (1) fill in, (2) seal, and (3) shrink the wound. Phase I - inflammatory, phase II - Proliferative or Reconstructive, Phase III - remodeling.

Autoimmunity

a disturbance in the immunologic tolerance of self-antigens.

Macrophage

a large phagocytic cell found in stationary form in the tissues or as a mobile white blood cell, especially at sites of infection

Bradykinin

causes dilation of blood vessels, acts with prostaglandins to stimulate nerve endings and induce pain, causes smooth muscle cell contraction, increases vascular permeability, and may increase leukocyte chemotaxis. Bradykinin induces smooth muscle contraction more slowly than histamine and, along with prostaglandins of the E series, is probably responsible for endothelial cell retraction and increased vascular permeability in the later phases of inflammation.

complement cascade

causes the harmful effects of immune complex deposition. The neutrophils bind to antibody and C3b contained in the complexes and attempt to ingest the immune complexes

Antigenic drift

emergence of new flu strains so need for new flu shots each year

Inflammatory mediators

histamine and serotonin (from mast cells), bradykinin (generated by activation of the complement cascade), prostaglandins (from neutrophils) and oxidants (from activated neutrophils mast cells and macrophages), act directly on the small blood vessels (venules) (increases vascular permeability).

Antigenic shifts

major changes, gene jumping. eg. Influenza A from avian + human virus strains, responsible for pandemics

Opsonin

molecules that tag microorganisms for destruction by cells of the inflammatory system, primarily neutrophils and macrophages

How to minimize contamination and scarring to a wound

o Contraction - occurs concurrently with granulation and reduces scar tissue needed for repair o Keep the wound clean use use petroleum jelly to keep the wound moist and cover the skin with an adhesive bandage. Change the bandage daily to keep the wound clean while it heals. o Treat the wound with antibiotics: After cleaning the wound, apply a thin layer of antibiotic ointment to prevent infection. Close and dress the wound: Closing clean wounds helps promote faster healing. Waterproof bandages and gauze work well for minor wounds. Deep open wounds may require stitches or staples.

Antigenic variation

o Mutation: Antigenic drift -emergence of new flu strains so need for new flu shots each year o Recombination: Antigenic shifts - major changes, gene jumping eg. Influenza A from avian + human virus strains, responsible for pandemics o Gene switching

Mast cells

releases granules and powerful chemical mediators, such as histamine, cytokines, granulocyte macrophage colony-stimulating factor (GM-CSF), leukotrienes, heparin, and many proteases into the environment. These chemical mediators cause the characteristic symptoms of allergy.

Local manifestations of acute inflammation (i.e., swelling, pain, heat, and redness)

result from vascular changes and the subsequent leakage of circulating components into the tissue. Heat and redness are the result of vasodilation and increased blood flow through the injured site. Swelling occurs as exudate (fluid and cells) accumulates. Swelling is usually accompanied by pain caused by pressure exerted by exudate accumulation, as well as the presence of soluble biochemical mediators such as prostaglandins and bradykinin. Loss of function at the cellular, tissue, or organ level is associated with these manifestations.

Allergy

the effects of hypersensitivity to environmental antigens, and immunity means the protective responses to antigens expressed by disease-causing agents.

Alloimmunity

when the immune system of one individual produces a reaction against tissues of another individual. Alloimmunity can be observed during immunologic reactions against transfusions, transplanted tissue, or the fetus during pregnancy.