Microbiology Homework 4
Which event happens first during cytotoxic T-cell activation? Production of IL-2 and gamma-interferon receptors CD8 binds to MHC molecules of infected cells Secretion of granzymes and perforin Clonal proliferation
CD8 binds to MHC molecules of infected cells
Which of the following is not a proposed explanation for the development of autoimmunity? Certain antigens in a person's diet could trigger the production of antibodies that cross-react with host tissues. If a pathogen has antigens that resemble host factors, it could trigger the production of antibodies that cross-react with host tissues. Cytopathic effects generated by a pathogen could encourage host antigen-presenting cells to process and present self-antigens to T cells. GeneticsCertain pathogens may release superantigens that inappropriately activate certain T cells against self-factors.
Certain antigens in a person's diet could trigger the production of antibodies that cross-react with host tissues.
Which of the following describes the classical pathway of complement activation? Complement proteins activate by coming into contact with certain blood-clotting proteins. Complement proteins activate by directly interacting with the pathogen. Complement proteins activate when triggered by macrophages or neutrophils. Complement proteins activate when mannose-binding lectin binds to the pathogen. Complement proteins activate when antibodies bind to a pathogen.
Complement proteins activate when antibodies bind to a pathogen.
Antipyretics such as ibuprofen and acetaminophen work in which of the following manners? Increase production of eicosanoids Decrease production of prostaglandins Prevent release of histamines Increase production of kinins
Decrease production of prostaglandins
The hygiene hypothesis proposes which of the following? Newborns and young children should be exposed to as many disease-causing microorganisms as possible to train their immune system to attack pathogens. Reducing the number of resident flora on our skin through degermination techniques decreases the likelihood of infection. Decreased handwashing in clinical settings may help to combat the rise in exogenous, antimicrobial-resistant bacterial infections. Decreasing diversity of our normal flora from increased antibiotic usage and changes in diet and lifestyle may lead to increased allergies and autoimmune disorders.
Decreasing diversity of our normal flora from increased antibiotic usage and changes in diet and lifestyle may lead to increased allergies and autoimmune disorders.
Which of the following statements concerning desensitization therapy is true? Desensitization therapy encourages plasma cells to produce IgG antibodies against the allergen. Desensitization therapy provokes a TH2 cell response. Desensitization therapy involves exposing patients to decreasing concentrations of an allergen over time (beginning with a concentrated dose of the allergen) in hopes of decreasing the allergic response. Desensitization therapy is most effective for food allergies.
Desensitization therapy encourages plasma cells to produce IgG antibodies against the allergen.
When does MHC-II loading occur? During the fusion of vesicles containing MHC-II proteins with vesicles containing digested pathogens During phagocytosis of an invading pathogen After passing through the endoplasmic reticulum During viral infection
During the fusion of vesicles containing MHC-II proteins with vesicles containing digested pathogens
Which of the following scenarios would be most likely to lead to graft-versus-host disease? A bone marrow is transplanted from an older, unaffected sibling to a younger sibling affected with severe combined immunodeficiency. Skin is moved from the patient's hip to a deep burn site on the patient's face. A kidney is transplanted from an identical twin to a twin sibling suffering from end-stage renal disease. A baboon heart is transplanted into a human with hypoplastic left heart syndrome.
A bone marrow is transplanted from an older, unaffected sibling to a younger sibling affected with severe combined immunodeficiency.
Which branch of the immune system produces antibodies? Innate cellular response Adaptive humoral response Adaptive cellular response Innate molecular response
Adaptive humoral response
Choose the false statement about immune responses. Adaptive immunity takes longer to respond than innate immunity. Adaptive immunity is specific to a particular antigen, while innate immunity is not. Adaptive immune responses are always the same, regardless of the threat encountered, while innate immune responses are not. Adaptive immunity has a memory component, while innate immunity does not.
Adaptive immune responses are always the same, regardless of the threat encountered, while innate immune responses are not.
When do helper T-cells develop into TH1 or TH2 cells? Before autostimulation After proliferation into a clonal population Immediately after the binding of the CD4 receptor After B cell activation
After proliferation into a clonal population
Which of the following scenarios is most concerning for development of hemolytic disease of the newborn? An Rh- mother pregnant with an Rh- fetus An Rh- mother pregnant with an Rh+ fetus An Rh+ mother carrying an Rh+ fetus An Rh+ mother carrying an Rh- fetus
An Rh- mother pregnant with an Rh+ fetus
What is the primary benefit of vaccination? Vaccines provide antibodies against the pathogen that persist forever in the body. Unvaccinated persons can never mount an immune response to a pathogen. Vaccinated persons get used to the symptoms of a disease. An immune response will occur quicker upon future exposure to the pathogen.
An immune response will occur quicker upon future exposure to the pathogen.
What makes agglutination by antibodies possible? Each antibody has at least two antigen-binding sites. Antibodies can recognize bacteria as well as viruses. Antibodies can inactivate toxins. Antibodies are produced by plasma cells.
Each antibody has at least two antigen-binding sites.
How can a sufficient humoral immune response occur if a plasma cell only lives for a few days? T cells can also produce antibodies. Each plasma cell can produce up to 2000 antibodies every second. Each plasma cell can proliferate into more plasma cells. Memory B cells can also produce antibodies.
Each plasma cell can produce up to 2000 antibodies every second.
What is an antigen? Any molecule that, when presented in the right context, will stimulate an immune response A cell that remains in the lymphatic tissues to rapidly recognize pathogens in a subsequent exposure A cell that organizes the cellular and humoral branches of adaptive immunity A molecule made by plasma cells
Any molecule that, when presented in the right context, will stimulate an immune response
Which of the following statements best describes the hygiene hypothesis as it relates to allergies? As a result of increased handwashing and improved universal healthcare precautions, the incidence of allergies and autoimmune disorders has decreased in developed countries. As a result of poorer, unsanitary living conditions, the number of allergies and autoimmune disorders has increased in developed countries. The decreased incidence of hypersensitivities seen in developed countries is attributable to the decreased number of microbial infections. As a result of increased antibiotic usage and cleaner foods and beverages, our normal gut microbiota has shifted, resulting in increased hypersensitivities in developed countries.
As a result of increased antibiotic usage and cleaner foods and beverages, our normal gut microbiota has shifted, resulting in increased hypersensitivities in developed countries.
Which type of vaccine could possibly cause a person to develop the disease? Inactivated killed vaccine Attenuated live vaccine Toxoid vaccine Toxoid vaccine and inactivated killed vaccine
Attenuated live vaccine
Which type of cell directly binds an antigen, rather than requiring an antigen-presenting cell to first process the antigen? T cytotoxic cells T helper cells Dendritic cells B cells
B cells
TH2 cells produce cytokines that activate natural killer cells. B cells. cytotoxic T-cells. macrophages.
B cells.
A patient with the antigens A and RH+ would not be able to receive blood from which of the following? B+ O- A+ A- O+
B+
What is the function of the CD8 receptor? Produce gamma interferon Produce IL-2 Activate cytokines Bind to MHC molecules
Bind to MHC molecules
What is the function of boosters? Boosters are the highly antigenic portions of the conjugated vaccines. Boosters are vaccines containing no pathogenic portions of the pathogen. Boosters help to kill the pathogens used in inactivated killed vaccines. Boosters are injections that are given periodically to maintain immunity.
Boosters are injections that are given periodically to maintain immunity.
Which of the following does not describe adaptive immunity? only in vertebrate animals evolved more recently generalized responses that don't vary based on the pathogen being fought matures over time recognizes pathogens it previously fought, allowing for quicker and more aggressive defense mobilization upon later exposures to the same agent
generalized responses that don't vary based on the pathogen being fought
Which of the following is NOT an autoimmune type IV hypersensitivity? multiple sclerosis graft-versus-host disease celiac disease Guillain-Barré syndrome, Hashimoto thyroiditis, multiple sclerosis, and celiac disease Hashimoto thyroiditis
graft-versus-host disease
In a recombinant vector vaccine, genetic material from a pathogen is placed into a ________ and introduced to human cells. pathogenic virus or bacteria harmless virus or bacteria human B or T cell human dendritic cell plasmid vector
harmless virus or bacteria
The influenza vaccine is an example of a(n) inactivated killed vaccine. DNA vaccine. conjugated vaccine. toxoid vaccine.
inactivated killed vaccine.
Which of the following allergies and treatments is mismatched? atopic dermatitis: usually treated topically with ointments that may contain steroid anti-inflammatory drugs food allergy: managed on a contact basis using antihistamines like Benadryl allergic asthma: inhaled drugs that open up the bronchi insect bite/sting allergy: continued preemptive treatment with an injected antibody preparation that ties up the patient's IgE antibodies anaphylaxis: epinephrine may be administered and emergency medical care must be sought
insect bite/sting allergy: continued preemptive treatment with an injected antibody preparation that ties up the patient's IgE antibodies
Antigen processing and presentation is a way for viruses to infect cells. is the way foreign cells engulf macrophages. is a way for a cell to give information about its activities. is only accomplished by bacterial cells.
is a way for a cell to give information about its activities.
Chronic inflammation is not useful or protective and promotes atherosclerosis, cancers, and neurodegenerative disorders. can take years to go away but will go away eventually. works to protect host tissues until all pathogens have been eradicated. can lead to muscle aches and fatigue as the body struggles to heal itself. is only of concern if the chronic inflammation is occurring in or next to the brain.
is not useful or protective and promotes atherosclerosis, cancers, and neurodegenerative disorders.
The cellular branch of adaptive immunity is organized by T helper cells and carried out by T cytotoxic cells. is based on the activity of both T and B cells. does not involve a memory function. is organized by T cytotoxic cells and carried out by T helper cells. is based on antibody production.
is organized by T helper cells and carried out by T cytotoxic cells.
A patient that experiences a tuberculin skin test reaction is experiencing which class of hypersensitivity reactions? type I type II type III type IV type V
type IV
Which cell type is the most numerous white blood cell in circulation, is the first leukocyte recruited from the bloodstream to injured tissues, and releases potent antimicrobial peptides? monocytes neutrophils basophils dendritic cells eosinophils
neutrophils
Which of the following hypersensitivities are T cell-mediated responses against self-antigens or otherwise harmless antigens? type I hypersensitivities and type II hypersensitivities type II hypersensitivities type III hypersensitivities type I hypersensitivities type IV hypersensitivities
type IV hypersensitivities
Although antivenom can save lives, it can also cause what type of reaction in certain patients? type I hypersensitivity type IV hypersensitivity nonautoimmune type III hypersensitivity autoimmune type III hypersensitivity type II hypersensitivity
nonautoimmune type III hypersensitivity
Which of the following is an outcome of complement activation? opsonization and cytolysis cytolysis opsonization cytolysis and inflammation opsonization, cytolysis, and inflammation
opsonization, cytolysis, and inflammation
All the following apply to B cells except reside in the lymphoid tissue. coordinate the humoral response by making antibodies. play a critical role in both the cellular and humoral responses. originate in the bone marrow.mature in the bone marrow.
play a critical role in both the cellular and humoral responses.
The general goal of first-line defenses is to prevent pathogen entry. tag intruders with a signaling molecule to identify them as foreign. weaken pathogens. isolate pathogens. destroy pathogens.
prevent pathogen entry.
Which of the following is not a main goal of inflammation? recruit immune defenses to the injured tissue deliver oxygen and nutrients transport chemical factors essential for tissue recovery produce localized heat and swelling in an effort to denature key bacterial proteins limit the spread of infectious agents
produce localized heat and swelling in an effort to denature key bacterial proteins
The aspect of the immune response that vaccines are based on is inflammation and fever.protection of the normal microbiota. stimulation of phagocytosis.stimulation of cellular, as opposed to humoral, immunity. production of memory cells and high antibody titers from pathogen exposure.
production of memory cells and high antibody titers from pathogen exposure.
In contrast to a primary immune response, immunological memory generates higher antibody titers. provides a rapid reactivation of both cellular and humoral responses. generates antibodies with enhanced affinity for its antigen. provides a rapid reactivation of both cellular and humoral responses including generating higher antibody titers and antibodies with increased affinity for its antigen. provides a rapid reactivation of humoral responses only by generating higher antibody titers and antibodies with increased affinity for its antigen.
provides a rapid reactivation of both cellular and humoral responses including generating higher antibody titers and antibodies with increased affinity for its antigen.
Which of the following features are shared between both innate and adaptive immunity? recognize diverse pathogens, eliminate identified invaders, and discriminate between self and foreign antigens respond immediately, remember antigens, and exist in all eukaryotic organisms recognize diverse pathogens and eliminate identified invaders discriminate between self and foreign antigens respond immediately and remember antigens
recognize diverse pathogens, eliminate identified invaders, and discriminate between self and foreign antigens
Antimicrobial peptides can do all of the following except insert themselves into target cell membranes. target intracellular components. disrupt plasma membrane and/or cell wall. regulate body temperature.stimulate leukocytes.
regulate body temperature.
What is the role of memory cells? remain in the lymphoid tissue to rapidly proliferate and differentiate upon subsequent exposure to the same pathogen circulate in the body at elevated levels to maintain an active attack against any possible pathogen prevent an immune response against members of the normal microbiota suppress the cellular response once the infection has passed provide immune protection specifically for central nervous system
remain in the lymphoid tissue to rapidly proliferate and differentiate upon subsequent exposure to the same pathogen
What are cytokines? enzymes that promote the replication and gathering of leukocytes carbohydrates which reduce inflammation in the body signaling proteins that help cells communicate with each other, initiating and coordinating immune actions alert hormones that trigger the body to prepare for injury by shrinking capillaries and increasing platelet production organic chemicals which stimulate fever via an increase in metabolism
signaling proteins that help cells communicate with each other, initiating and coordinating immune actions
Allografts are similar to the host, but not genetically identical. transplants from self, like a self-skin graft from one part of the body to another location. interspecies transplants. transplanted tissue from an identical twin. transplants that are made in an immune-privileged site in the body are the least likely to be rejected.
similar to the host, but not genetically identical.
Adjuvants appear to work by stimulating cytokine release. encouraging the uptake and processing of antigens by dendritic cells. stimulating isotype-switching in B cells and cytokine release. stimulating cytokine release and encouraging the uptake and processing of antigens by dendritic cells. stimulating isotype-switching in B cells.
stimulating cytokine release and encouraging the uptake and processing of antigens by dendritic cells.
Which of the following statements describes the purpose of gene shuffling? Gene shuffling eliminates lymphocyte clones that respond to autoantigens. Gene shuffling allows an individual to switch from producing IgM antibody to IgG antibody. Gene shuffling allows for propagation of a specific lymphocyte whose receptor corresponds to the invading antigen. Gene shuffling generates an enormous repertoire of antigen receptors during lymphocyte development.
Gene shuffling generates an enormous repertoire of antigen receptors during lymphocyte development.
Which of the following is not a type I hypersensitivity reaction? Goodpasture syndrome seasonal allergies food allergy eczema allergy-based asthma
Goodpasture syndrome
Which molecule triggers apoptosis? Granzyme IL-2MHC Gamma-interferon Perforin
Granzyme
Which of the following acts as a pro-inflammatory factor? Histamine Epinephrine Histidine Antihistamine
Histamine
________ reactions are inappropriate responses against a threat that lead to immune-based pathologies such as allergy and autoimmunity. Aversion Autopathic Hypersensitivity Endopathic Sensitivity
Hypersensitivity
Place the stages of adaptive immunity in order from first to last. I. Antigen elimination and memory II. Lymphocyte activation III. Antigen presentation IV. Lymphocyte proliferation and differentiation
III, II, IV, I
The branches of adaptive immunity are the cellular response and the memory response. the cellular response, the humoral response, and the memory response. the humoral response and the memory response. the cellular response and the humoral response. the antigen response and the memory response.
the cellular response and the humoral response.
Choose the false statement. IgG binds to the surface of mast cells and basophils. During sensitization, allergens trigger IgE production. Degranulation occurs when allergens bind IgE that is on the surface of mast cells or basophils. In desensitization immune therapy, TH1 cells encourage specific B cells to make IgG against the allergen.
IgG binds to the surface of mast cells and basophils.
What is graft-versus-host disease? Immune system cells in transplanted bone marrow attack the body of its new host. It occurs when tissue from an allograft is rejected. It occurs when tissue from a xenograft is rejected. It occurs when tissue from an isograft is rejected. Immune system cells of the host attack the newly transplanted bone marrow and reject it.
Immune system cells in transplanted bone marrow attack the body of its new host.
Which of the following statements is true concerning the alternative complement cascade? The alternative complement system was the first complement cascade discovered. The alternative complement pathway is activated when host mannose-binding lectin associates with certain sugars on a microbe's surface. The alternative complement cascade is triggered by antibodies bound to an invading agent. In the alternative complement cascade, complement proteins directly interact with the invading agent.
In the alternative complement cascade, complement proteins directly interact with the invading agent. Submit
Which of the following mechanisms occurs in a patient suffering from systemic lupus erythematosus? Insoluble antigen-antibody complexes form and deposit in tissues, attracting complement, which in turn activates inflammation cascades and recruits inflammation-promoting leukocytes. Complement is recruited by antigen-antibody complexes and ultimately lyses host cells. IgE antibodies with antigen bound will trigger degranulation of mast cells. Cytotoxic T cells lyse target host cells after activation by TH1 helper cells.
Insoluble antigen-antibody complexes form and deposit in tissues, attracting complement, which in turn activates inflammation cascades and recruits inflammation-promoting leukocytes.
What is the difference between an intolerance and an allergy? Intolerances tend to have a delayed onset of symptoms, while allergic reactions occur rapidly. Intolerances can change over a patient's lifetime, but allergic reactions do not change throughout a patient's life. Intolerances have mild symptoms, while allergic reactions can be life threatening. Intolerances produce symptoms that last several days, while patients having an allergic reaction recover in less than 24 hours. Intolerances occur due to a patient's exposure to the environment, while allergic reactions are genetically determined.
Intolerances tend to have a delayed onset of symptoms, while allergic reactions occur rapidly.
What type of antigen typically binds to MHC I to present an MCH I-antigen complex? Intracellular antigen Exogenous antigen Phagocytized bacterial proteins Extracellular antigen
Intracellular antigen
Why are leukocytes so central to second-line molecular defenses? Leukocytes remove second-line molecular defenses to inhibit damage to healthy tissues in the surrounding area. Leukocytes respond to the production of second-line molecular defenses. Leukocytes have nothing to do with second-line molecular defenses. Leukocytes trigger other cells of the immune system to produce second-line molecular defenses. Leukocytes produce second-line molecular defenses.
Leukocytes produce second-line molecular defenses.
Based on the animation, T cells recognized the antigen displayed by what protein of the B cell? BCR Antigen CD4 TCR MHC
MHC
What is the role of MHC I in the immune response? MHC I is found on all body cells except red blood cells. MHC I is found on all body cells except red blood cells and presents a sample of cellular proteins, including those of any intracellular pathogens, to T cells. MHC I is found only on antigen-presenting cells. MHC I is found only on antigen-presenting cells and presents a sample of cellular proteins, including those of any intracellular pathogens, to T cells. MHC I presents a sample of cellular proteins, including those of any intracellular pathogens, to T cells.
MHC I is found on all body cells except red blood cells and presents a sample of cellular proteins, including those of any intracellular pathogens, to T cells.
Which statement is not true about MHC II? MHC II interacts with the CD4 receptor on T helper cells. MHC II is present only on antigen-presenting cells. When bound to antigen, MHC II serves a key role in activation of the appropriate T cells. MHC II primarily displays extracellular antigens which have been phagocytized. MHC II interacts with both the CD4 and CD8 receptors on T helper and T cytotoxic cells.
MHC II interacts with both the CD4 and CD8 receptors on T helper and T cytotoxic cells.
Which proteins on the antigen-presenting cell are recognized by the helper T-cell? IL-1 receptors MHC proteins IL-2 receptors CD8 receptors
MHC proteins
Which of the cells listed below can present antigens on Class II MHC proteins? Virus infected epithelial cells Healthy epithelial cells Tumor cells Macrophages
Macrophages
When a person has previously been vaccinated against a viral pathogen, which cells are activated if that same pathogen re-enters the host's cells months or years later? Memory B cells Memory cytotoxic T cells Bacterial pathogens Helper T cells
Memory cytotoxic T cells
Which of the following statements concerning natural killer cells is true? Natural killer cells provide protection against viruses, bacteria, parasites, and tumors. Natural killer cells are classified as granulocytes. Natural killer cells are part of the adaptive immune system. Natural killer cells are created as monocytes cross from the circulatory system into tissues.
Natural killer cells provide protection against viruses, bacteria, parasites, and tumors.
Why would a body cell that is not a phagocyte need to present antigens? All cells of the body can engulf invading cells. Non-phagocytic body cells can become infected with a virus. Antigens are infectious and can spread to normal cells. Antigens are required for cell-to-cell attachment.
Non-phagocytic body cells can become infected with a virus.
Where are MHC molecules located on a cell? Inside the cell cytoplasmIn the nucleus They are not associated with any one location on the cell On the surface of the cell
On the surface of the cell
Antibodies are secreted from which type of cell? Dendritic cells T helper cells T cytotoxic cells Plasma cells
Plasma cells
What is produced by the process of clonal expansion? Plasma cells, T cells, and memory B cells Plasma cells Plasma cells and memory B cells Memory B cells
Plasma cells and memory B cells
What is the role of plasma cells in humoral immunity? Plasma cells are phagocytes. Plasma cells engulf viruses. Plasma cells produce antibodies. Plasma cells activate the complement system. Plasma cells neutralize toxins.
Plasma cells produce antibodies
Herd immunity describes the process of immunizing animals so that people do not acquire zoonotic diseases. the social phenomenon of vaccine refusal reinforced by internet memes and social media the protection conferred to non-immunized people when a sizable portion of the rest of the population is immunized. the process of spacing out vaccinations in infants to just one per doctor's visit. the temporary immunity an infant receives from its mother during gestation and from breastfeeding.
the protection conferred to non-immunized people when a sizable portion of the rest of the population is immunized.
A drawback of all inactivated vaccines is that they may cause secondary transmission from the immunized person to another host. they are quickly cleared from the body, limiting antigen exposure. they require complex genetic engineering techniques to produce. they may mutate to a more virulent form. they are likely to cause disease in immunocompromised hosts.
they are quickly cleared from the body, limiting antigen exposure.
Which of the following are primary lymphoid tissues? thymus and lymph nodes spleen and mucosa-associated lymphoid tissue thymus and bone marrow lymph nodes and spleen bone marrow and mucosa-associated lymphatic lymphoid tissue
thymus and bone marrow
Conjugate vaccines which link the target antigen to a more immunogenic antigen are usually for vaccines against bacterial exotoxins. vaccines against Gram-negative endotoxin. vaccines against viral envelopes. vaccines against viral nucleic acid. vaccines against bacterial polysaccharide antigens.
vaccines against bacterial polysaccharide antigens.
The Hepatitis B vaccine is which type of vaccine? Subunit vaccine Inactivated killed vaccine DNA vaccine Toxoid vaccine
Subunit vaccine
Choose the false statement. T helper cells directly combat antigens. T cytotoxic cells directly combat antigens. Antibodies activate classical complement cascades. B cells usually require T cells for full activation.
T helper cells directly combat antigens.
An antigen that is potent enough to activate a B cell on its own is known as antibodies. T-independent antigens. T-dependent antigens. BCR.
T-independent antigens.
Which T cell class is incorrectly matched with its description? TH: identified by the CD4 proteins on the cell surface TH2: stimulate B cells to make antibodies TH1: stimulate TC cells Treg: ensures that immune responses subside once a threat subsides TC: attack other T cells during self-tolerance screening
TC: attack other T cells during self-tolerance screening
Which receptor on the helper T-cell recognizes the specific antigen from an antigen-presenting cell? CD4 IL-2 Receptors IL-1 Receptors TCR
TCR
Natural killer cells are activated by TH2 cells. TH1 cells. bacterial cells. antigen-presenting cells.
TH1 cells.
Which of the following most accurately describes how a pathogenic bacterium might be affected by antibodies? The antibodies may coat the surface of the bacteria (opsonization), allowing for it to be tagged for phagocytosis. The antibodies may stick to multiple bacteria, causing agglutination. The antibodies may block proteins necessary for binding the pathogen to the host. The antibodies may block proteins necessary for binding the pathogen to the host, may opsonize the bacterium, or may agglutinate bacteria.
The antibodies may block proteins necessary for binding the pathogen to the host, may opsonize the bacterium, or may agglutinate bacteria.
Which organelle assists directly with the presentation of MHC-I antigens? The endoplasmic reticulum The Golgi apparatus The mitochondria The nucleusThe phagosome
The endoplasmic reticulum
Which of the following is an example of a mechanical barrier? Lysozyme found in breast milk breaks down bacterial cell walls. Antimicrobial peptides made by leukocytes are used to destroy pathogens throughout the body. The mucociliary escalator sweeps mucus away from the lungs and toward the mouth. Epithelial cells block pathogen entry into the skin.
The mucociliary escalator sweeps mucus away from the lungs and toward the mouth.
What is apoptosis? A protein molecule that forms a pore in the membranes of infected cells. The process of programmed cell death. The receptor on a cytotoxic T-cell that recognizes MHC molecules. The proliferation of cytotoxic T-cells.
The process of programmed cell death.
Which statement provides the best explanation of the need for self-tolerance screening of lymphocytes? Self-tolerance involves "self" lymphocytes which bind to and form a protective layer over all body tissues. Lymphocytes which would attack the body's own tissues are never generated. The process which generates the vast array of diverse antigen receptors is a highly-controlled process, so the generation of receptors which can bind to the body's own tissues is a rare occurrence due to a genetic mutation. It is necessary to have some lymphocytes with receptors that are self-tolerant to respond to intracellular infections by viruses. The process which generates the vast array of diverse antigen receptors is a random process that could produce receptors which will bind to the body's own tissues.
The process which generates the vast array of diverse antigen receptors is a random process that could produce receptors which will bind to the body's own tissues.
Which of the following best characterizes clonal selection? The production of identical T cells producing the same antibody The production of different antigens by the same B cell The production of identical B cells producing different antibodies The production of identical B cells producing the same antibody
The production of identical B cells producing the same antibody
Which of the following statements concerning the secondary response is true? In order to stimulate an immune reaction, the secondary immune response requires a higher concentration of antigen than the primary immune response. The secondary immune response is slower than the primary immune response. The secondary response results in production of antibodies with a higher affinity for the antigen. The secondary immune response is stronger than the primary immune response due to the increased production of IgM antibody from plasma cells.
The secondary response results in production of antibodies with a higher affinity for the antigen.
What is the hallmark of a conjugated vaccine? They contain the DNA from a pathogenic virus. These vaccines contain weakly antigenic elements plus a more potent antigenic protein. They contain only the non-pathogenic elements of a pathogen, not the entire cell.
These vaccines contain weakly antigenic elements plus a more potent antigenic protein
What is a feature of the small fragments presented by MHC-I proteins? They are derived from bacteria. They are small peptides, roughly 8-10 amino acids long. They are small fragments of nucleic acids, 8-10 nucleotides in length. They are large proteins from the host.
They are small peptides, roughly 8-10 amino acids long.
Which of the following statements about type III hypersensitivities is false? Insoluble complexes are deposited in tissues. They develop when IgD or IgE antibodies bind to insoluble targets. Relatively large antigen-antibody aggregates form. Antibodies involved in type III reactions can be made as part of an autoimmune response or formed as a normal response to foreign antigens. Massive inflammation is triggered by the antibody aggregates activating complement cascades.
They develop when IgD or IgE antibodies bind to insoluble targets.
How do phagocytes communicate to other cells what they have captured? They present antigens from engulfed foreign cells. They engulf virally infected cells. They spread viruses to other cells.
They present antigens from engulfed foreign cells.
What is the fate of activated cytotoxic T-cells? They can mature and attack infected cells. They are infected by viruses. They are destroyed via apoptosis. They can differentiate into long-lived memory T-cells. Each activated cytotoxic T-cell proliferates, forming a clone of cells specific to the same antigen. They proliferate into a clone of cells specific to the same antigen; some of these cells then differentiate into long-lived memory T-cells, while others mature to attack infected cells.
They proliferate into a clone of cells specific to the same antigen; some of these cells then differentiate into long-lived memory T-cells, while others mature to attack infected cells.
What is edema? the hardening of infected lymph nodes the spreading of a pathogen from the circulatory system to the lymphatic system irregular heart palpitations tissue swelling when a capillary bursts and is releasing fluid under the skin
tissue swelling
Allergies are classified as: Type I hypersensitivities Type II hypersensitivities Type III hypersensitivities Type IV hypersensitivities
Type I hypersensitivities
The amount of antibody present in the blood is termed the antibody ________. titer isotype specificity effector affinity
titer
Which of the following hypersensitivity classes is properly listed with its description? Type II, allergies Type I, delayed hypersensitivity Type III, immune complex Type IV, cytotoxic
Type III, immune complex
Which of the following statements regarding type IV hypersensitivities is true? Type IV hypersensitivities are delayed and typically manifest slowly over 12--72 hours after the stimulating antigen is encountered. Type IV hypersensitivities consist of only nonautoimmune hypersensitivities, as autoimmune hypersensitivities are exclusively classified as type III hypersensitivities. Type IV hypersensitivities are antibody-mediated. An example of a nonautoimmune type IV hypersensitivity is serum sickness.
Type IV hypersensitivities are delayed and typically manifest slowly over 12--72 hours after the stimulating antigen is encountered.
Why are type IV hypersensitivities called delayed hypersensitivity reactions? Although type IV reactions can cause skin lesions, watery eyes, and a runny nose, treatment for those symptoms needs to be delayed due to the rapid drop in blood pressure which soon follows and needs to be dealt with first. Type IV reactions manifest slowly over 12-72 hours after the stimulating antigen is encountered. Type IV reactions affect nerve cells and cause nerve impulses to slow resulting in visibly slower movements from the patient. Type IV reactions only occur in underdeveloped countries and medical attention often needs to be delayed until the patient can be brought to a hospital. Drugs to counteract type IV reactions are large and slow to be absorbed by the affected cells causing the patient to tolerate a lengthy symptomatic phase before recovery is complete.
Type IV reactions manifest slowly over 12-72 hours after the stimulating antigen is encountered.
What does a vaccine contain? T cells against a pathogen Live active pathogens Weakened or killed pathogen or parts of a pathogen B cells against a pathogen
Weakened or killed pathogen or parts of a pathogen
What is the role of B cell receptors (BCRs) and T cell receptors (TCRs) in the immune response? to combine with haptens so they can stimulate an immune response to release chemicals which destroy pathogens to communicate with lymphocytes and other white blood cells to release the cytokines needs for immune cell stimulation to recognize specific epitopes of an antigen
to recognize specific epitopes of an antigen
How is the immune system able to recognize a limitless number of different antigens and epitopes? While each lymphocyte carries receptors that recognize only one type of epitope, the immune system produces a wide variety of lymphocytes each of which carries unique receptors. A genetic "memory" of the pathogens your parents encountered (and their parents and so on) is passed on to each generation, increasing the number of possible responses over time. If a lymphocyte encounters an antigen it does not recognize, it immediately switches receptors until it finds one that is a match. Each lymphocyte is coated with many different receptors, each of which recognizes a different epitope. Each lymphocyte is coated with many different receptors, each of which recognizes a different epitope AND the immune system produces a wide variety of lymphocytes.
While each lymphocyte carries receptors that recognize only one type of epitope, the immune system produces a wide variety of lymphocytes each of which carries unique receptors.
In 1984, in one of the most famous cross-species transplantations, a baboon heart was transplanted into an infant (Baby Fae). This surgery is an example of which of the following types of grafts? Xenograft Allograft Autograft Isograft
Xenograft
Which of the following scenarios is an example of a primary immunodeficiency? An individual is given cyclosporine to prevent host-versus-graft disease during a kidney transplantation. A patient has an atopic response to penicillin and is given hydrocortisone cream to relieve inflammation. Your patient acquires HIV-AIDS later in life and has a resulting low CD4 T cell count. Your patient is born with agammaglobulinemia, a genetic condition that leads to decreased antibody production.
Your patient is born with agammaglobulinemia, a genetic condition that leads to decreased antibody production.
A major factor in the re-emergence of vaccine-preventable diseases in the early 21st century has been fears of biological weapons after the September 11, 2001 terrorist attacks turned public sentiment against vaccines. a flawed research study incorrectly linking vaccination to breast cancer was published in the late 1990s. microbes can develop resistance to vaccines just as they to do antibiotics.a flawed research study incorrectly linking vaccination to autism was published in the late 1990s. concerns about animal rights have led people to avoid pharmaceuticals and other products that might have been tested on animals.
a flawed research study incorrectly linking vaccination to autism was published in the late 1990s.
A DNA vaccine involves placing genes into a plasmid and introducing the plasmid into human cells. Human cells then transcribe and translate the genes to produce antigen which immunize the recipient. What is the source of the genes being introduced? a harmless virus a member of the patient's microbiome human B or T cells a pathogen a laboratory animal (such as a mouse)
a pathogen
Antibodies do all the following except increase phagocytosis by agglutination of antigens. neutralize antigens to prevent binding to host cells. increase phagocytosis by opsonization. activate killing by T cytotoxic cells. activate the complement cascade.
activate killing by T cytotoxic cells.
Which of the following is not a hallmark sign of primary immunodeficiencies? recurring uncommon severe acute persistent
acute
A vaccine additive which enhances the body's natural immune response is called a(n) toxoid. attenuant. recombinant. adjuvant. booster.
adjuvant.
Which of the following class of hypersensitivity reactions is not associated with autoimmunity? allergies immune complex delayed hypersensitivity cytotoxic autoimmune
allergies
Which of the following would not cause serum sickness? anti-inflammatory drugs antivenom sulfa drugs penicillin antitoxin
anti-inflammatory drugs
Which of the following are used to treat serum sickness? antihistamines anti-inflammatory drugs anti-inflammatory drugs, antihistamines, and sulfa drugs anti-inflammatory drugs and antihistamines sulfa drugs
anti-inflammatory drugs and antihistamines
Which of the following are the three phases of inflammation? vascular changes, leukocyte recruitment, and resolution cytokine production, vasodilation, and phagocytosis chemoattractant production, exudate release, and healing vasoactive release, diapedesis, and angiogenesis margination, histamine release, and apoptosis
vascular changes, leukocyte recruitment, and resolution
A substance that may trigger an immune response, if presented in the right context is termed a(n) antibody. effector. cytokine. antigen. hapten.
antigen.
Which of the following is an example of a chemical barrier? skin antimicrobial peptides urine mucus tears
antimicrobial peptides
The difference between T cell activation by normal antigens and T cell activation by superantigens is that superantigens are not processed and presented by APCs. suppress cytokine release.cause nonspecific activation of many T cells at once, including those that would not normally recognize the antigen. cause nonspecific activation of many T cells at once, including those that would not normally recognize the antigen and suppress cytokine release. are not processed and presented by APCs and cause nonspecific activation of many T cells at once, including those that would not normally recognize the antigen.
are not processed and presented by APCs and cause nonspecific activation of many T cells at once, including those that would not normally recognize the antigen.
What two types of patients help demonstrate that cancer can be considered a failure of the immune system? nervous system complication patients and pulmonary system complication patients migraine patients and digestive issue patients hepatitis C infected patients and human papilloma viruses infected patients rheumatoid arthritis patients and multiple sclerosis patients transplant patients and HIV/AIDS patients
transplant patients and HIV/AIDS patients
Live attenuated vaccines are the closest to the actual infectious agent encountered in nature and stimulate potent immune responses to multiple antigens on the pathogen. require the use of an adjuvant.stimulate potent immune responses to multiple antigens on the pathogen. are closest to the actual infectious agent encountered in nature and require the use of an adjuvant. are the closest to the actual infectious agent encountered in nature.
are the closest to the actual infectious agent encountered in nature and stimulate potent immune responses to multiple antigens on the pathogen.
T-independent antigens are usually polysaccharides and able to bind multiple B cell receptors on a given B cell. are usually polysaccharides. are usually proteins. are able to bind multiple B cell receptors on a given B cell. may be polysaccharides or proteins, and are not able to bind multiple B cell receptors on a given B cell.
are usually polysaccharides and able to bind multiple B cell receptors on a given B cell.
What are the two categories of second-line defenses? antibodies and platelets platelets and red blood cells assorted molecular factors and leukocytes mucus and lysozyme red blood cells and antibodies
assorted molecular factors and leukocytes
Which is not a step in the process of B cell activation by a T-dependent antigen? release of cytokines by the T helper cell provide the second activation signal for the B cell interaction between co-stimulatory proteins on the B and T cells processing and displaying the antigen with MHC II on the B cell binding of the antigen to the B cell receptor binding of the antigen to a T helper cell receptor
binding of the antigen to a T helper cell receptor
Autoimmune disorders are acute infections that target the immune system. chronic conditions that develop from the immune system attacking healthy self-tissues that should normally be left alone. genetic conditions present from birth that continually degrade over time. short-term mistakes made by the immune system that are quickly recognized and self-limited. caused by the immune system not being stimulated enough in adolescence and as a result is over reactive and can cross-react with host tissues.
chronic conditions that develop from the immune system attacking healthy self-tissues that should normally be left alone.
Which of the following can cause primary immunodeficiencies? congenital immunodeficiency infectious agents aging medical interventions systemic disorders
congenital immunodeficiency
All the following apply to T cells except reside in the lymphoid tissue. coordinate the humoral response by making antibodies. originate in the bone marrow.have the capacity to recognize virtually any type of antigen. mature in the thymus.
coordinate the humoral response by making antibodies.
T helper cells release _____ to activate B cells. MHC II cytokines antibodies MHC I
cytokines
Which cell type works to prevent our immune system from attacking self and from over-reacting to nonthreatening substances, is abundant in tissues next to body openings, and phagocytizes a broad range of antigens? lymphocytes natural killer cells monocytes dendritic cells macrophages
dendritic cells
Which of the following pairs is not an example of a cytokine and its function? chemokines: recruit white blood cells to areas of injury or infection eicosanoids: promote the replication and gathering of leukocytes interferons: produced by virus-infected cells to signal neighboring cells to mount antiviral defenses interleukins: regulate inflammation, fever, T cell development, and innate and adaptive immune responses tumor necrosis factors: induce inflammation and kills tumor cells
eicosanoids: promote the replication and gathering of leukocytes
Which of the following is not a cardinal sign of inflammation? pain loss of function redness fever swelling
fever
Secondary lymphoid tissues are monocytes and dendritic cells. are neutrophils and eosinophils. filter lymph and sample surrounding body sites for antigens which are brought into contact with the leukocytes that reside in secondary lymphoid tissues to stimulate an immune response. are where leukocytes mature.are where formed elements in blood are produced.
filter lymph and sample surrounding body sites for antigens which are brought into contact with the leukocytes that reside in secondary lymphoid tissues to stimulate an immune response.
Localized anaphylaxis tends to feature isolated symptoms such as anxiety, nausea, or swelling. decreased blood pressure, shortness of breath, or abdominal pain. fainting, chest pain, or vomiting.confusion, hives, or hoarseness. watery eyes, a runny nose, or a confined rash.
watery eyes, a runny nose, or a confined rash.
In what situation is hemolytic disease of the newborn a life and death situation? when an RH- women and an RH+ male have intercourse when an RH- mom is pregnant for the first time with an RH+ fetus when an RH- mom is pregnant for the second time with an RH+ fetus when an RH+ women and an RH- male have intercourse when an RH+ mom is pregnant for the second time with an RH- fetus
when an RH- mom is pregnant for the second time with an RH+ fetus
What is the general classification used to categorize leukocytes? It depends on the age of the cell, as all agranulocytes start off as a granulocyte and later change their function and structure over the life of the cell. whether or not the cells contain a nucleus whether the cells originate from primary or secondary lymphoid tissues whether or not leukocytes have granules in their cytoplasm that are visible when stained and then viewed by light microscopy whether they function as part of the innate or adaptive immune system
whether or not leukocytes have granules in their cytoplasm that are visible when stained and then viewed by light microscopy
