Chapter 09: Inflammation and Immunity

The membrane attack complex formed by complement is similar in function to a. CD4+. b. granzymes. c. CD8. d. perforin.

d. perforin. The membrane attack complex functions in a similar manner to perforin. CD4+ do not function similar to the membrane attack complex. Granzymes do not function similar to the membrane attack complex. CD8 does not function similar to the membrane attack complex.

Which clinical finding is most indicative of an acute bacterial infection? a. Increased (band) neutrophils b. Elevated temperature c. Elevated erythrocyte sedimentation rate d. Elevated WBC count

a. Increased (band) neutrophils Neutrophils are early responders and most active in bacterial infections, and the number of neutrophil bands indicates the severity of the infection. Elevated temperature can occur in infection caused by any organism. The erythrocyte sedimentation rate is non-specific for the type of organism causing an infection. The total WBC count can increase in any infection. The specific type of WBC that is elevated indicates the type of organism involved.

Functions of antibodies include (Select all that apply.) a. antigen agglutination. b. antigen precipitation. c. opsonization. d. phagocytosis. e. complement activation.

a. antigen agglutination. b. antigen precipitation. c. opsonization. e. complement activation. Antibody functions include antigen precipitation, agglutination, neutralization, and opsonization. Antibodies also activate complement. Antibodies do not phagocytize

Passive immunity is provided by (Select all that apply.) a. transfer of preformed human antibodies. b. injection of human immune globulin. c. injection with preformed animal antibodies. d. vaccines with dead or altered organisms. e. active infections.

a. transfer of preformed human antibodies. b. injection of human immune globulin. c. injection with preformed animal antibodies. Passive immunity is provided by immunization with preformed antibodies from either humans or animals, and by injection of human immune globulin. Vaccination with dead or altered organisms provides active immunity. Active infection induces active immunity.

Immunity to a specific organism can be determined by a. active phase protein count. b. antibody titer. c. erythrocyte sedimentation rate. d. WBC count.

b. antibody titer. Specific serum antibody concentration for a particular organism can be measured by a blood antibody titer. Active phase protein count indicates level of inflammation. Erythrocyte sedimentation rate indicates degree of inflammation. WBC count helps determine if infection with any organism is present.

Leukocytosis with a "shift to the left" refers to a. elevated segmented neutrophils. b. elevated immature neutrophils. c. decreased monocytes. d. decreased immature neutrophils.

b. elevated immature neutrophils. During acute inflammation, the bone marrow releases stored neutrophils. As they are consumed, the demand exceeds the production resulting in an immature (band) neutrophil. Segmented neutrophils are mature neutrophils. Monocytes are immature macrophages and are only 5% of the total WBC. Leukocytosis with a "shift to the left" refers to increased immature leukocytes.

Activation of the complement cascade results in (Select all that apply.) a. antibody production. b. inflammation. c. immunosuppression. d. autoimmunity. e. chemotaxis.

b. inflammation. e. chemotaxis. Activation of the complement cascade result is enhanced inflammation and chemotaxis. The complement cascade does not result in antibody production or autoimmunity. It also does not result in immunosuppression; it enhances immune function.

Proteins that are increased in the bloodstream during acute inflammation are called a. membrane attack complexes. b. selectin receptors. c. acute phase proteins. d. major histocompatibility complexes.

c. acute phase proteins. Acute phase proteins are produced in the liver during acute inflammation and circulate in the bloodstream. Two of the most important acute phase proteins are C-reactive protein (CRP) and serum amyloid A. Membrane attack complexes are porelike structures that function within the complement system. Selectin receptors are receptors on neutrophils that help neutrophils stick to capillary endothelium. Major histocompatibility complexes are a cluster of genes on chromosome 6 involved in antigen presentation.

Antigen-presenting cells function to a. display foreign antigen on their cell surfaces bound to MHC. b. stimulate cytokine production by macrophages. c. phagocytose and degrade foreign antigens. d. initiate the complement cascade by way of the alternative pathway.

a. display foreign antigen on their cell surfaces bound to MHC. Antigen-presenting cells function to display foreign antigen on their cell surfaces bound to MHC for T-cell recognition. Antigen-presenting cells do not stimulate cytokine production or initiate the complement cascade. They also do not phagocytose and degrade foreign antigens, but instead present these to T cells for these functions.

The primary function of eosinophils is to a. kill parasitic helminths (worms). b. kill bacteria. c. stop viral replication. d. phagocytize fungi.

a. kill parasitic helminths (worms). The primary function of eosinophils is to kill parasitic helminths (worms); this is evident by the elevation in eosinophil level in parasitic infections. Neutrophils, not eosinophils, function to kill bacteria. Eosinophils have no role in stopping viral replication. The primary role of eosinophils does not involve phagocytizing fungi.

The mononuclear phagocyte system consists of (Select all that apply.) a. monocytes and tissue macrophages. b. dendritic cells. c. bone marrow stem cells. d. antibody-secreting plasma cells. e. basophils.

a. monocytes and tissue macrophages. b. dendritic cells. The mononuclear phagocyte system is composed of monocytes and macrophages, and dendritic cells that are widely distributed throughout body tissues. Monocytes from the circulating blood migrate to organs and tissues to become macrophages. The mononuclear phagocyte system does not include the bone marrow stem cells, antibody-secreting plasma cells, or basophils.

Characteristics of complement include (Select all that apply.) a. stimulating chemotaxis. b. lysing target cells. c. having multiple plasma proteins. d. being synthesized in the bone marrow. e. enhancing phagocytosis.

a. stimulating chemotaxis. b. lysing target cells. c. having multiple plasma proteins. e. enhancing phagocytosis. Complement functions to stimulate chemotaxis and thereby enhance phagocytosis. Complement consists of 20 plasma proteins that can lyse target cells. Complement proteins are synthesized in the liver and by macrophages and neutrophils, not in the bone marrow.

Functions of B cells include a. synthesizing antibodies. b. secreting cytokines. c. killing antigen-presenting cells. d. stimulating B cells. e. killing virally infected cells.

a. synthesizing antibodies. B lymphocytes mature into plasma cells and synthesize antibodies. B cells do not secrete cytokines, kill antigen-presenting cells, or kill virally infected cells; T cells do these.

Functions of T cells include (Select all that apply.) a. synthesizing antibodies. b. secreting cytokines. c. killing antigen-presenting cells. d. stimulating of B cells. e. killing virally infected cells.

b. secreting cytokines. c. killing antigen-presenting cells. d. stimulating of B cells. e. killing virally infected cells. Certain types of T cells (T helper 2) secrete cytokines that stimulate B-cell proliferation. Other T cells (cytotoxic T cells) kill antigen-presenting cells and recognize and destroy virally infected cells. T cells do not synthesize antibodies.

The "classical pathway" for activation of the complement cascade is triggered by a. activation of C3. b. inflammation. c. first recognition of an antigen. d. antigen-antibody complexes.

d. antigen-antibody complexes. The classical pathway for activation of the complement cascade is triggered by the presence of IgG or IgM antigen-antibody complexes. Activation of C3 initiates the alternative pathway. Inflammation does not initiate the classical pathway, but instead inflammation is enhanced by the complement cascade. First recognition of an antigen initiates the lectin pathway or the alternative pathway.

The spleen is an important defense against infection, because it a. activates the complement cascade. b. initiates inflammation. c. controls phagocytosis. d. filters the blood.

d. filters the blood. The spleen filters the blood; macrophages in the spleen filter out foreign substances. Lymphocytes activated in the spleen can be transported to other lymphoid tissue to fight infection. The spleen does not activate the complement cascade, initiate inflammation, or have a role in controlling phagocytosis.

Interleukin-1, interleukin-6, and tumor necrosis factor- are inflammatory cytokines secreted by a. plasma cells. b. neutrophils. c. lymphocytes. d. macrophages.

d. macrophages. Macrophages secrete cytokines, including IL-1, IL-6, IL-12, and tumor necrosis factor- that promote inflammation. Plasma cells, neutrophils, and lymphocytes do not secrete inflammatory cytokines.

Active immunity involves (Select all that apply.) a. injection of preformed human antibodies. b. injection of human immune globulin. c. injection with preformed animal antibodies. d. vaccines with dead or altered organisms. e. active infections.

d. vaccines with dead or altered organisms. e. active infections. Active immunity is provided by vaccination with dead or altered organisms and by active infections. Injection of preformed antibodies from either humans or animals produces passive immunity. Injection of human immune globulin produces passive immunity.

The primary function of kinins is a. phagocytosis of antigens. b. production of antibodies. c. to limit immune reactions. d. vasodilation to enhance inflammation.

d. vasodilation to enhance inflammation. Kinins are especially active in inflammation via powerful vasodilation to bring immune cells to the site of infection. Kinins are not phagocytic, but bring phagocytes to an area of infection via vasodilation. B cells produce antibodies. Kinins do not limit immune reactions.