A&P 2 ch 21
First line of defense.
Intact skin and mucous membranes
Second line of defense.
Third line of defense.
Innate defense system.
Inflammatory response, skin and mucous membranes
Adaptive defense system.
Enables quick and efficient response to secondary exposure to antigen
Absence results in no immune response
Helper T cell
Forms antibody producing cells
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.
Protects mucosal barriers.
Involved in allergies.
Along with IgM, this is a B cell receptor.
First to peak during a primary immune response.
Virus infected cells secrete complement to "warn" other cells of the presence of virus.
The mechanism of the "lethal hit" of cytotoxic T cells and NK cells involves a protein called perforin.
Cellular ingestion and destruction of particulate matter is called phagocytosis.
The respiratory burst produced by some macrophages releases free radicals.
The directional movement of cells in response to chemicals is called chemotaxis.
Substances capable of triggering the adaptive immune system and provoking an immune response are called antigens.
Soluble proteins secreted by plasma cells are called antibodies.
33) A given pathogen will provoke either a cell-mediated response or an antibody-mediated response but not both.
Fever is seldom beneficial because it speeds up the cellular metabolic rate and will not allow antigen-antibody reactions to occur.
Monoclonal antibodies can be specific for several antigenic determinants.
Both T cells and B cells must accomplish double recognition: They must simultaneously recognize self and nonself to be activated.
Some immunocompetent cells will never be called to service in our lifetime.
Anaphylactic shock can result from an immediate hypersensitivity where the allergen enters the blood
Adaptive immunity is provided only by lymphocytes that secrete antibodies.
A transfusion reaction is a subacute hypersensitivity to foreign red blood cells.
Somatic recombination by B cells allows each B cell to form its own unique antibody genes.
Antibodies cn act both intracellularly and extracellularly.
It is our genes, not antigens, that determine what specific foreign substances our immune system will be able to recognize and resist.
The classical complement pathway involves antibodies.
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?
B lymphocytes develop immunocompetence in the ________.
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 ________.
51) The antibody molecule is held together by ________ bonds.
In clonal selection of B cells, which substance is responsible for determining which cells will eventually become cloned?
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 ________.
55) Small molecules that bind with self-proteins to produce antigenic substances are called ________.
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?
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?
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.
Which of the following is a part of the second line of defense against microorganisms?
Which of the following is characteristic of complete antigens?
reactivity with an antibody
68) 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 ________.
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 ________.
Which of the following would be classified as a delayed hypersensitivity reaction?
allergic contact dermatitis
Innate immune system defenses include ________.
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
production is regulated by chemicals that reset the body's thermostat to a higher setting
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.
Select the correct statement about active and passive immunity.
Active and passive humoral immunity are both mechanisms of adaptive immunity that use antibodies.
82) Cytotoxic T cells ________.
are the only T cells that can directly attack and kill other cells
83) 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.
86) 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
90) 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?
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?
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 B cell?
Suppressor factors are ________ that suppress the immune system.
Pure antibody preparations specific for a single antigenic determinant are called ________ antibodies.
The most common type of immediate hypersensitivity is ________.
Natural killer cells can lyse and kill cancer cells and virus-infected body cells ________ the immune system is activated.
Septic shock is a dangerous condition where the ________ are released unchecked, making the capillaries very leaky and thus depleting blood fluids.
Harmful or disease-causing microorganisms are called ________.
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 ________.
The antibody that becomes bound to mast cells and basophils and causes the cells to release histamine and other chemicals is ________.
A(n) ________ is a cell hybrid formed from the fusion of tumor cells and B lymphocytes.
111) Failure of developing T cells to recognize self MHC during positive selection results in
An autoimmune disease that severely impairs renal function is ________.
What is the antigen challenge, and where does it usually take place?
the first encounter between an immunocompetent lymphocyte and an invading antigen. It usually takes place in the spleen or a lymph node, but may happen in any lymphoid tissue
Why are regulatory T cells important to the immune process?
They are vital in the final stopping of an immune response after the antigen is inactivated. They may also help prevent autoimmune reactions
What is the most likely type of hypersensitivity associated with an agonizingly itchy case of poison ivy?
delayed hypersensitivity called allergic contact
What is the most likely type of hypersensitivity associated with the appearance of hives after eating shellfish?
an immediate hypersensitivity in the form of a local anaphylactic reaction.
What is the most likely type of hypersensitivity associated with a positive TB test?
a type of delayed hypersensitivity
Children born without a thymus must be kept in a germ-free environment if they are to survive. Explain why this is necessary.
If the thymus fails to develop, the T cells will not mature and
become immunocompetent. If T cell function is
disrupted, there is no resistance to disease
What are the signs of inflammation?
The four signs of inflammation are swelling, redness, heat, and pain.
The signs are caused by local vasodilation and
increased capillary permeability.
how does inflammation serve as a protective function?
the process helps to dilute harmful substances that may be present; brings in large quantities of oxygen, nutrients, and cells necessary for the repair process; and allows the entry of clotting proteins. Pain helps immobilize the injury
What are two general mechanisms by which autoimmune diseases could arise?
1) Appearance of new self-proteins in the circulation that have not
previously been exposed to the immune system. 2)
An immune response to foreign antigens resembling self-antigens
What are some of the drawbacks of passive humoral immunity?
The effects are short lived; it does not trigger memory cell production; and your body degrades the antibodies.