packet 21 chapter21
Area where B cells become immunocompetent.
bone marrow
Area where T cells become immunocompetent.
thymus
Area where activated immunocompetent B and T cells recirculate.
blood
Area seeded by immunocompetent B and T cells.
lymph node
Area where antigen challenge and clonal selection are most likely to occur.
lymph node
First line of defense.
Intact skin and mucous membranes
Second line of defense.
Inflammatory response
Third line of defense.
Immune response
Innate defense system.
Inflammatory response and skin and mucous membranes
Adaptive defense system.
Immune response
Enables quick and efficient response to secondary exposure to antigen
Memory cell
Absence results in no immune response
Helper T cell
Forms antibody producing cells
B cell
Kills cancer cells and virus infected body cells
Cytotoxic T cell
Slows or stops the immune response
Regulatory T cell
Main antibody of both primary and secondary immune response.
IgG
Protects mucosal barriers.
IgA
Involved in allergies.
IgE
Along with IgM, this is a B cell receptor.
IgD
First to peak during a primary immune response.
IgM
Which of the following is characteristic of antibodies?
composed of heavy and light polypeptide chains
Which of the following is associated with passive immunity?
passage of IgG antibodies from a pregnant mother to her fetus
Which of the following is not a type of T cell?
antigenic
B lymphocytes develop immunocompetence in the ________.
bone marrow
Which of the following is not a function of the inflammatory response?
replaces injured tissues with connective tissue
The redness and heat of an inflamed area are due to a local hyperemia caused by ________.
vasodilation
The antibody molecule is held together by ________ bonds.
disulfide
In clonal selection of B cells, which substance is responsible for determining which cells will eventually become cloned?
antigen
Which of the following statements regarding NK cells is a false or incorrect statement?
NK cells are a type of neutrophil
The process whereby neutrophils and other white blood cells are attracted to an inflammatory site is called ________.
chemotaxis
Small molecules that bind with self-proteins to produce antigenic substances are called ________.
haptens
Which of the following is the correct sequence of events in phagocytosis?
chemotaxis, adherence, ingestion, digestion, killing
Which of the following is not a role of activated complement?
prevention of immediate hypersensitivity reactions
Which of the following does not respond to cell-mediated immunity?
pathogens in the lumen of the stomach
Which of the following cells predominate at the sites of chronic infections?
Macrophages
Interferons ________.
interfere with viral replication within cells
Which of the following determine(s) what specific foreign substances our adaptive immune system will be able to recognize and resist?
Our genes
Regulatory T cells ________.
may function in preventing autoimmune reactions
Select the correct definition about tissue grafts.
Isografts are between identical twins.
Which of the statements below does not describe antigens?
Antigens only come from microbes.
Activated T cells and macrophages release ________ to mobilize immune cells and attract other leukocytes into the area.
Cytokines
Which of the following is a part of the second line of defense against microorganisms?
phagocytes
Which of the following is characteristic of complete antigens?
reactivity with an antibody
B cells respond to the initial antigen challenge by ________.
producing progeny cells that include plasma cells and memory cells
T-cell activation requires ________.
antigen binding and co-stimulation
Cancer cells and virus-infected body cells can be killed before activation of adaptive immunity by ________.
natural killer cells
Complement proteins and antibodies coat a microorganism and provide binding sites, enabling macrophages and neutrophils to phagocytize the organism. This phenomenon is termed ________.
opsonization
Which of the following is not characteristic of the adaptive immune system?
It is specific for a given organ.
Monoclonal antibodies are used for the diagnosis of all of the following except ________.
juvenile diabetes
Which of the following would be classified as a delayed hypersensitivity reaction?
allergic contact dermatitis
Innate immune system defenses include ________.
phagocytosis
Which of the following statements is INCORRECT or FALSE?
Class II MHC molecules appear only on the surface of antigen-presenting cells, thymic cells, and T cells that have been activated by exposure to antigens.
Phagocyte mobilization involves ________.
mainly neutrophil and macrophage migration into inflamed areas
Fever ________.
production is regulated by chemicals that reset the body's thermostat to a higher setting
Immunocompetence ________.
is the ability of individual cells to recognize a specific antigen by binding to it
Select the correct statement about the prevention of immune attack on "self."
Tolerance is developed during fetal life
Cytotoxic T cells ________.
are the only T cells that can directly attack and kill other cells
Helper T cells ________.
function in the adaptive immune system activation
Select the correct statement about immunodeficiency..
The causative agent in acquired immune deficiency syndrome (AIDS) is a virus that recognizes CD4 proteins.
Which of the following is true of immediate hypersensitivities?
They involve IgE antibodies and the release of histamine from mast cells and basophils.
Delayed hypersensitivities ________.
include allergic contact dermatitis
Natural killer (NK) cells ________.
can kill cancer cells before the immune system is activated
Select the correct statement about antigens.
One antigen may have many different antigenic determinants and may therefore cause the formation of more than one antibody.
Clonal selection of B cells ________.
results in the formation of plasma cells
The primary immune response ________.
has a lag period while B cells proliferate and differentiate into plasma cells
Select the correct statement about the function of antibodies.
Complement fixation is the main mechanism by which antibodies provide protection.
Which of the following cells is the most critical cell in immunity?
helper T cell
Which of the following is not an autoimmune disease?
type II diabetes
Which of the following is not a mechanism for the development of autoimmune disorders?
a second exposure to an allergen
Which of the following is not a complement activation pathway?
lactate pathway
Antibody functions include all of the following except ________.
cross-linking cell-bound antigens on red blood cells when blood types are properly matched
Which statement is true about T cells?
Their proliferation is enhanced by interleukins 1 and 2.
Which of the following is not a method by which antibodies work?
direct cell lysis
What is the role of interferon in defense against disease?
protects cells that have not yet been infected by viruses
Which of the following statements is a false or incorrect statement?
After becoming immunocompetent, the naive T cells and B cells are exported to the bone marrow where the encounters with antigens occur.
Which immunoglobulin class is attached to the external surface of B cells and acts as an antigen receptor of the B cell?
IgD
Suppressor factors are ________ that suppress the immune system.
cytokines
Pure antibody preparations specific for a single antigenic determinant are called ________ antibodies.
monoclonal
The most common type of immediate hypersensitivity is ________.
allergy
Natural killer cells can lyse and kill cancer cells and virus-infected body cells ________ the immune system is activated.
before
Septic shock is a dangerous condition where the ________ are released unchecked, making the capillaries very leaky and thus depleting blood fluids.
Cytokines
Harmful or disease-causing microorganisms are called ________.
Pathogens
A group of at least 20 plasma proteins that normally circulate in an inactive state and are a major mechanism for destroying foreign substances in the body are referred to as ________.
Complement
The antibody that becomes bound to mast cells and basophils and causes the cells to release histamine and other chemicals is ________.
Ige
A(n) ________ is a cell hybrid formed from the fusion of tumor cells and B lymphocytes.
Hybridoma
Failure of developing T cells to recognize self MHC during positive selection results in ________.
Apoptosis
An autoimmune disease that severely impairs renal function is ________.
Glomerulonephritis