A&P Ch20 Flashcards
What constitutes the body's first line of defense against disease?
intact skin and mucous membranes
Which of the following is a role of interferons (IFNs)?
IFNs help the body combat viral infections.
Which defense mechanism results in redness, heat, pain, and swelling?
Which of the following is an effect of complement activation?
Cellular immunity is attributed to the action of __________.
What mobilizes the adaptive defenses and provokes an immune response?
Which of the following cells engulf antigens and present fragments of them on their own surfaces, where they can be recognized by cells that will deal with them?
__________ is the most abundant class of antibodies in plasma.
Why are children given vaccinations?
to develop antibodies against various diseases
Class II MHC proteins are found on which of the following cell types?
Which class of MHC proteins presents exogenous antigens?
class II MHC proteins
Class I MHC proteins are recognized by which of the following cell types (that are destined to become T cells)?
Which of the following types of cells display protein fragments produced by the cancer within them?
all nucleated cells
Which major class of lymphocytes become cytotoxic T cells?
What occurs if a T cell binds to an antigen and the T cell does NOT receive a co-stimulatory signal?
The T cell enters a state of anergy.
What types of antigen are recognized by T cells?
processed fragments of protein antigens displayed on surfaces of body cells
Treatment of an abscess often requires that it be surgically drained because ______.
the wall of the abscess prevents neutrophils from entering the pus and attacking the pathogens
Binding of an eosinophil to an antibody-coated parasitic worm involves binding of the antibody's stem region to a(n) ______.
plasma membrane protein on the eosinophil's surface
Tears and mucus membranes would be a part of which defense system?
innate external defenses
Phagocytotic cells such as macrophages identify a variety of enemies by recognizing markers unique to pathogens. They would be classified as which type of defense system?
innate internal defenses
What cells make antibodies?
plasma B cells
What is the name of the unique area (specific region) that a lymphocyte recognizes and binds to?
an antigenic determinant
What type of immunity can be transferred by bodily fluids from one person to another, thus conferring immunity to the recipient?
If a virus attacks a cell, which type of immunity would be activated?
cell-mediated immunity (cellular immunity)
Cancer cells would be attacked by which of the following cells?
Cytotoxic T cells
What is the role of helper T cells in the adaptive immune response?
Helper T cells activate B cells and cytotoxic T lymphocytes to kill infected host cells.
What is meant by the clonal expansion of a B cell?
An activated B cell divides into cells that give rise to memory B cells and plasma cells.
The student who caught the cold caused by this specificRhinovirus was exposed to the exact same Rhinovirus 18 months later. What component of the immune system will protect her from getting the same cold again?
Memory B cells
Correctly order the steps involved cellular immunity:
- The Tc recognizes the infected host cell
- The Tc interacts with epitope presented by MHC-I on the dendritic cell
- The Tc secretes perforin and granzyme, causing apoptosis
- The helper T cell activates the Tc cell
Which of the following is NOT a step used by cytotoxic T cells to kill infected host cells?
Recognition of infected host cell using its CD4 glycoprotein
Place the following steps of phagocytosis in the order that they occur:
- Endosome fuses with lysozome
- Dendritic cell engulfs Rhinovirus
- Epitopes are attached to MHC-II
- Digestion of theRhinovirus
- MHC-II plus the attached epitope move to the outside of the dendritic cell
Which pair of molecules do NOT directly interact with one another?
BCR and TCR
Which of the following is NOT a step that ultimately leads to antibody production?
Activation of cytotoxic T cells by helper T cells
A person who has AIDS contracts rare and often life-threatening infections because their helper T cell count is so low. Which of the following components of the immune response still respond to antigen despite the low helper T cell count?
Clonal selection of B cells
Which of the following statements is true?
Adaptive defenses include both humoral and cellular immunity.
Which of the following is NOT a characteristic of Natural Killer (NK) cells?
NK cells recognize abnormal or cancer cells by a specific antigen on their cell membrane.
Which of the following innate internal defenses work by interfering with viral replication?
How do phagocytes recognize foreign cells or bacteria?
The phagocytes recognize molecules on pathogens not normally found on body cells.
Which of the innate defense mechanisms can lyse bacteria and mark cells for phagocytosis?
Which of the following can act as opsonins on bacteria, thus enhancing phagocytosis?
antibodies and complement proteins
Which letter represents the formation of a phagolysosome resulting from the fusion of a lysosome with the phagocytic vesicle? Select from letters A-D.
What protein can be released by infected cells to help protect cells that have not yet been infected?
How do interferons protect against infection in healthy cells?
Interferons block viral reproduction in healthy cells through the production of antiviral proteins.
What is the specific target of interferons?
nearby healthy cells
With what does our immune system coat pathogens to facilitate their capture and accelerate phagocytosis?
Which letter represents the adhesion of the phagocyte to the pathogen? Select from letters A-D.
Four (or five) cardinal signs indicate inflammation. What specific sign of inflammation is the result of exudate in the tissue spaces?
Which of the following inflammatory chemicals is released by mast cells?
Which of the following is NOT one of the cardinal signs of inflammation?
When do neutrophils enter the blood from the red bone marrow, in response to leukocytosis-inducing factors?
What is the main event of chemotaxis?
Neutrophils and other WBCs migrate up the gradient of chemotactic agents to the site of injury.
Neutrophils flatten and squeeze between the endothelial cells of the capillary walls during what process?
Which of the following is (are) NOT a part of the innate immune defenses?
Proinflammatory signals include all of the following, EXCEPT __________.
__________ is the final step of phagocyte mobilization.
Pyrogens induce __________.
Which of the following is NOT a nonspecific internal defense against disease?
Which antimicrobial protein is produced by a virus-infected cell?
A physician orders Tylenol for a temperature greater than 101 degrees F. The patient's temperature is 100.4 F. What is the rationale for not medicating a fever of 100.4 F?
A mild or moderate fever is an adaptive response that seems to benefit the body. Bacteria need large amounts of zinc and iron to multiply. During fever, the liver and spleen sequester iron and zinc that bacteria need to multiply.
When the white blood cell count is depressed, the classic signs of infection such as redness, heat, and swelling are not manifested. In this case, should the nurse avoid administering aspirin?
Yes, aspirin should be avoided because aspirin would disguise a fever that would indicate infection.
The process whereby neutrophils and other white blood cells are attracted to an inflammatory site is 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 cells predominate at the sites of chronic infections?
interfere with viral replication within cells
Which of the following is a part of the second line of defense against microorganisms?
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 ________.
Innate immune system defenses include ________.
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
Natural killer (NK) cells ________.
can kill cancer cells before the immune system is activated
Which of the following is not a function of the inflammatory response?
replaces injured tissues with connective tissue
Which of the following is not a complement activation pathway?
What is the role of interferon in defense against disease?
protects cells that have not yet been infected by viruses
The redness and heat of an inflamed area are due to a local hyperemia caused by ________.
Which of the following statements regarding NK cells is a false or incorrect statement?
NK cells are a type of neutrophil.
Virus infected cells secrete complement to "warn" other cells of the presence of virus.
The classical complement pathway involves antibodies.
The respiratory burst produced by some macrophages releases free radicals.
The directional movement of cells in response to chemicals is called chemotaxis.
Fever is seldom beneficial because it speeds up the cellular metabolic rate and will not allow antigen-antibody reactions to occur.
Which of the following do NOT serve as antigen-presenting cells (APC)?
natural killer cells
Small molecules that bind with self-proteins to produce antigenic substances are called ________.
Which of the following is characteristic of complete antigens?
reactivity with an antibody
Which of the following is not characteristic of the adaptive immune system?
It is specific for a given organ.
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.
is the ability of individual cells to recognize a specific antigen by binding to it
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.
Substances capable of triggering the adaptive immune system and provoking an immune response are called antigens.
Which cells mature in the thymus?
How does a lymphocyte become immunocompetent?
Lymphocytes must be able to recognize their one specific antigen by binding to it.
What are B and T cells called that have not yet been exposed to an antigen?
Choose the true statement regarding the primary versus the secondary immune response.
A primary response results when naïve lymphocytes are activated, while a secondary response is a result of activating memory cells.
__________ immunity protects a baby who is fed breast milk.
T cells achieve self-tolerance in the __________.
Which of the following statements does NOT describe the adaptive immune response?
It occurs immediately after the body is challenged by foreign material.
Which of the following determine(s) what specific foreign substances our adaptive immune system will be able to recognize and resist?
Which of the statements below does not describe antigens?
Antigens only come from microbes.
B lymphocytes develop immunocompetence in the ________.
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.
Some immunocompetent cells will never be called to service in our lifetime.
Adaptive immunity is provided only by lymphocytes that secrete antibodies.
Somatic recombination by B cells allows each B cell to form its own unique antibody genes.
It is our genes, not antigens, that determine what specific foreign substances our immune system will be able to recognize and resist.
How would you classify the antivenom used to treat poisonous snake bites?
passive immunity, artificially acquired
Which of the following exemplifies passive immunity?
Which of the following best illustrates artificially acquired active humoral immunity?
What part of the antibody's structure determines its class?
constant (C) region
Which immunoglobulin class can cross the placenta to provide naturally acquired passive immunity to the fetus?
What is the first antibody released in the primary response and usually indicates infection?
Which mechanism occurs when antibodies block specific sites on viruses or bacterial exotoxins?
Which of the following mechanisms of antibody action occur when red blood cells clump due to a transfusion of mismatched blood?
Which mechanism of antibody action results in cell lysis?
complement fixation and activation
__________ are lymphocytes that directly kill virus- infected cells.
Cytotoxic T cells
Antigens bound to MHC II activate __________.
helper T cells
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
B cells respond to the initial antigen challenge by ________.
producing progeny cells that include plasma cells and memory cells
Monoclonal antibodies are used for the diagnosis of all of the following except ________.
Select the correct statement about active and passive immunity.
Active and passive humoral immunity are both mechanisms of adaptive immunity that use antibodies.
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.
Antibody functions include all of the following except ________.
cross-linking cell-bound antigens on red blood cells when blood types are properly matched
Which of the following is not a method by which antibodies work?
direct cell lysis
Which immunoglobulin class is attached to the external surface of B cells and acts as an antigen receptor of the B cell?
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?
Antibodies cn act both intracellularly and extracellularly.
Soluble proteins secreted by plasma cells are called antibodies.
What type of cell is the precursor to the helper T cell?
What type of cell is a precursor to the cytotoxic T cell?
What activates CD8 cells?
antigen fragments on class I MHC proteins
What type of T cell can directly attack and kill other cells, such as virus-infected cells?
cytotoxin T (TC) cells
Cytotoxic T (TC) cells check cells of the body for identity flags to see if they look they way they are supposed to. What is this process called?
Which type of T cell will recognize antigens associated with an allograft?
cytotoxin T (TC) cell
__________ are lymphocytes that coordinate cellular and humoral immune responses.
Helper T cells
Which class of tissue graft is the least likely to be accepted by a patient's body?
Which of the following are mismatched?
immediate hypersensitivity: allergic contact dermatitis
Fever is one of the cardinal signs of inflammation.
Which cell of the immune system is absolutely required for an adaptive immune response in that it helps activate both humoral and cellular immune responses?
helper T cell
Which of the following does not respond to cell-mediated immunity?
pathogens in the lumen of the stomach
Regulatory T cells ________.
may function in preventing autoimmune reactions
Select the correct definition about tissue grafts.
Isografts are between identical twins.
Activated T cells and macrophages release ________ to mobilize immune cells and attract other leukocytes into the area.
T-cell activation requires ________.
antigen binding and co-stimulation
Which of the following is not a type of T cell?
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
Which of the following cells is the most critical cell in immunity?
helper T cell
Which statement is true about T cells?
Their proliferation is enhanced by interleukins 1 and 2.
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.
The mechanism of the "lethal hit" of cytotoxic T cells and NK cells involves a protein called perforin.
A given pathogen will provoke either a cell-mediated response or an antibody-mediated response but not both.
MHC I proteins (major histocompatibility class I proteins) are found on most cells of the body.
A 36-year-old man enters the hospital in an extremely debilitated condition. He has purple-brown skin lesions (a symptom of Kaposi's sarcoma) and a persistent cough. A physical examination reveals swollen lymph nodes, and laboratory tests find a very low lymphocyte count. Information taken during the personal history reveals that he has multiple sex partners with whom he frequently engages in unprotected sex. What is likely to be the man's problem and what is his prognosis?
He is probably suffering from AIDS. His outlook is poor once the disease has progressed to this advanced stage. There is no cure, and drug therapy has had limited short-term success.
Which of the following would be classified as a delayed hypersensitivity reaction?
allergic contact dermatitis
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
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
Anaphylactic shock can result from an immediate hypersensitivity where the allergen enters the blood.
A transfusion reaction is a subacute hypersensitivity to foreign red blood cells.