chapter 21 immune system Flashcards

The innate external defense system includes

A. cells and chemicals (for example, phagocytes).

B. skin and mucus membranes.

C. B and T cells.

Which of the following innate internal defenses could be described as "cells that kill body cells that have become infected or are cancerous?"

Which of the following innate internal defenses could be described as "cells that kill body cells that have become infected or are cancerous?"

A. Cytotoxic T cells

B. Phagocytes

C. Interferons

D. Natural killer cells

Which cell phagocytizes more pathogens?

A. Neutrophils

B. Monocytes that become macrophages once inside the tissue

C. Interferons

How do phagocytes recognize foreign cells or bacteria?

A. The foreign cells or bacteria secrete chemicals that the phagocytes recognize.

B. The phagocytes recognize molecules on pathogens not normally found on body cells.

C. It looks for the absence of normally occurring self-proteins.

Which of the following can act as opsonins on bacteria, thus enhancing phagocytosis?

A. Interferons

B. Natural killer cells

C. Antibodies and compliment proteins

Natural killer cells are a type of lymphocyte that recognizes abnormal cells. How does it "know" that a cell is an abnormal cell?

A. It looks for the absence of normally occurring self-proteins.

B. It recognizes a specific antigen on the cell surface

C. The phagocytes recognize molecules on pathogens not normally found on body cells.

Which of the antimicrobial proteins do the following three things: (1) interfere with viral replication, (2) modulate inflammation, and (3) activate immune cells.

A. Interferons

B. Compliment proteins

C. Cytokines

D. Natural killer cells

Which of the following is a group of proteins that enhance both the innate and specific defense mechanisms and can even kill some bacteria by themselves?

A. Cytokines

B. Compliment proteins

C. Interferons

Which of the following is NOT a cardinal sign of inflammation?

A. Pain

B. Redness

C. Numbness

D. Swelling

Which of the following is NOT an inflammatory mediator?

A. Prostaglandins

B. Components of the compliment system

C. Histamine

D. Antibodies

Pathogens are classified according to size. Which of the following is the smallest?

A.Bacteria

B. Viruses

C. Parasitic worms

D. Fungi

The skin would be classified as which type of defense?

A. Adaptive defense

B. Innate internal defense

C. Innate external defense

Which of the following defenses identify enemies by recognizing a limited number of markers unique to pathogens?

A. Innate internal defenses

B. Adaptive defenses

C. Innate external defenses

Which of the following defenses identify just one specific bacterium, virus, etc.?

A. Innate external defenses

B. Adaptive defenses

C. Innate internal defenses

Which of the following defenses use memory in order to recognize a specific invader?

A. Innate internal defenses

B. Innate external defenses

C. Adaptive defenses

The special shape that a lymphocyte identifies is called the:

A. antibody.

B. antigen.

C. antigenic determinant.

What cells make antibodies?

A. Memory T cells

B. Memory B cells

C. Plasma B cells

D. Cytotoxic T cells

The adaptive defense system includes:

A. tears and mucous membranes.

B. B and T cells.

C. cells and chemicals in body fluids.

A cell that has been invaded by a virus would be attacked by which of the following cells?

A. T cells

B. B cells

C. Cytotoxic T cells

D. Plasma B cells

If a pathogen is located in the extracellular fluid, which type of immunity would be activated?

A. Cellular

B. Humoral

C. antibody.

D. antigen.

To avoid an autoimmune disease, lymphoctes must avoid attacking:

A. self-antigens.

B. antigenic determinants.

C. antigens on pathogens.

The surface of a B cell is studded with 10,000-100,000 lymphatic antigen receptors that can bind optimally with:

A. a class of antigenic determinants.

B. many antigenic determinants.

C. only one antigenic determinant.

T-cell receptors:

A. are Y shaped and basically a membrane-bound antibody.

B. recognize antigen fragments housed in cell MHC proteins

C. A class of antigenic determinants

Anchoring the receptor in the membrane and signaling the cell when the receptor is bound is a function of which part of the antigen receptor?

A. The constant region

B. The variable region

C. The cortex

D. The medulla

Immature T cells migrate from the bone marrow to the thymus to become immunocompetent. Where in the thymus do they form new antigen receptors?

A. The cortex

B. The medulla

C. The constant region

D. The variable region

T cells are tested to determine whether they can recognize self-antigens. This process is known as:

A. positive selection.

B. negative selection.

C. the cortex

What is the immune system attacking in Grave's disease?

A. Myelin in the nervous system

B. TSH receptors

C. Red blood cells

D. Insulin-secreting cells in the pancreas

What is the best method for a naive lymphocyte to encounter its specific antigen?

A. Wait for the antigen to come to it

B. Hunt for the antigen

When B cells undergo clonal expansion, the effector cells are:

A. plasma B cells.

B. memory B cells.

C. secondary

D. primary

Vaccinations allow our bodies to generate a __________ immune response when we encounter the antigen.

A. secondary

B. primary

Antibodies that are free in the extracellular fluid are known as:

A. immunoglobulins or gamma globulins.

B. antigen receptors.

C. The stem (constant region)

D. The variable region

What portion of the antibody determines whether an antibody can activate complement proteins or act as an opsonin?

A. The stem (constant region)

B. The variable region

C. antigen receptors

Which of the following is NOT one of the five classes of antibodies?

A. IgM

B. IgA

C. IgD

D. IgT

Which of the following classes constitutes the largest fraction of circulating antibodies?

A. IgG

B. IgA

C. IgM

D. IgD

Antibodies in breast milk allow the passive transfer of immunity from mother to baby. Which class of antibody is transferred in breast milk?

A. IgG

B. IgM

C. IgD

D. IgA

When exposed to an allergen such as pollen, the body makes what class of antibodies?

A. IgE

B. IgA

C. IgM

D. IgD

Which class of antibodies is located on the surface of naive B cells (along with IgM antibodies), acts as antigen receptors, and participates in activating the B cell?

A. IgD

B. IgE

C. IgG

D. IgA

B cells usually encounter their specific antigens in the outer cortex of the lymph node. What happens when the B cell encounters the antigen?

A. The B cell releases perforins, which cause the antigen to lyse.

B. The antigen is brought into the B cell and the peptide segment is displayed on the surface bound to MHC proteins.

C. The activated B cell releases antibodies that destroy the antigen.

As the B cells begin dividing during the primary immune response, they begin secreting IgM or form germinal centers in the follicle. Which of the following events results in the cells producing IgG, IgA, or IgE antibodies?

A. Antibody maturation

B. Differentiation

C. Antibody class switching

Injection of antibodies for rabies is an example of which type of immunity?

A. Passive, naturally acquired

B. Passive, artificially acquired

C. Active, naturally acquired

D. Active, artificially acquired

A nonself substance that can provoke an immune response is called a(n) __________.

A. immunoglobulin

B. colony-stimulating factor

C. interferon

D. antigen

E. antibody

Active artificially acquired immunity is a result of __________.

A. contact with a pathogen

B. vaccination

C. antibodies passed on from mother to fetus through the placenta

D. antibodies passed on from mother to baby through breast milk

E. contact with toxins secreted by pathogen

Complement proteins work by __________.

A. producing antibodies

B. forming pores in the membranes of target cells

C. phagocytosis of target cells

D. neutralization of antigens

E. creating an impermeable barrier

Cytotoxic T cells kill target cells __________.

A. through injection of tumor necrosis factor

B. by releasing oxidizing agents

C. by phagocytosis

D. by secreting antibodies

E. through insertion of perforins into the target’s membrane

Lymphocytes that develop immunocompetence in the thymus are __________.

A. NK cells

B. T lymphocytes

C. macrophages

D. B lymphocytes

Saliva and lacrimal fluids contain which enzyme that destroys bacteria?

A. lysozyme

B. amylase

C. pepsin

D. reverse transcriptase

E. trypsin

Which immune cell is able to respond quickly after any subsequent encounter with the same antigen?

A. plasma cell

B. memory cell

C. helper T cell

D. antigen-presenting cell

E. basophil

Which of the following is/are secreted by leukocytes and macrophages and result(s) in a fever?

A. antibodies

B. pyrogens

C. histamine

D. heparin

E. keratin

Which type of disease results from the inability of the immune system to distinguish self- from nonself-antigens?

A. autoimmune disease

B. SCID

C. anaphylaxis

D. immunodeficiency

E. allergy

When a localized area exhibits increased capillary filtration, hyperemia, and swelling, it is an indication that __________.

A. antibodies are phagocytizing target cells

B. antigens are present

C. fever is developing

D. an immune response is underway

E. inflammation is occurring

Which cells do NOT have a direct role in phagocytosis?

A. macrophages

B. dendritic cells

C. NK cells

D. neutrophils

Which cells stimulate both arms of the immune response?

A. plasma cells

B. killer T cells

C. complement cells

D. basophils

E. helper T cells

Which nonspecific defense cells specialize in attacking cancer cells and virus-infected cells?

A. natural killer cells

B. helper T lymphocytes

C. basophils

D. macrophages

E. plasma cells

Which of the following is/are a nonspecific barrier defense?

A. complements

B. mucous membranes

C. macrophages

D. antibodies

E. natural killer cells

Which of the following statements is characteristic of a secondary humoral response?

A. It results in less antibody secretion.

B. It results in less memory-cell circulation.

C. It occurs much more rapidly than a primary response.

D. It triggers fever.

E. It occurs only in the spleen.

Which type of molecule is produced by virus-infected cells to communicate to noninfected cells the presence of a virus?

A. pyrogen

B. interleukin

C. interferon

D. complement

E. antigen

Which of the following is/are NOT a surface barrier to pathogen influx?

A. complement cascade

B. skin secretions

C. saliva and tears

D. mucous membranes

Which of the following is NOT one of the cardinal signs of inflammation?

A. redness

B. pain

C. swelling

D. opsonization

The process that begins when a helper T cell binds to a class II MHC protein on a displaying cell is known as __________.

A. costimulation

B. T cell proliferation

C. self-antigen recognition

D. antigen proliferation

All of the following are examples of autoimmune disorders EXCEPT __________.

A. systemic lupus erythematosus (SLE)

B. rheumatoid arthritis

C. sickle-cell anemia

D. Graves’ disease

E. myasthenia gravis

Which of the following is/are NOT an innate defense mechanism of the body?

A. fever

B. skin

C. B lymphocytes

D. inflammation

Which of the following is the first step in an inflammatory response?

A. release of leukocytosis-inducing factor

B. positive chemotaxis

C. diapedesis

D. adhesion of the neutrophil’s cell-adhesion molecules to antigen

In the respiratory burst, __________ are released; these have a potent cell-killing ability.

A. free radicals

B. neutrophils

C. platelet-derived growth factors

D. histamines

Which of the following is NOT a key characteristic of adaptive immunity?

A. It is specific.

B. Its primary response is fast.

C. It is systemic.

D. It has memory.

Toll-like receptors are found on __________.

A. neutrophils

B. macrophages

C. lymphocytes

D. mast cells

Interferons can be used to treat all of the following EXCEPT __________.

A. muscular dystrophy

B. cancer

C. viral infections

D. hepatitis C

Which of the following is NOT a function of interferons?

A. They mobilize natural killer cells.

B. They are not virus-specific.

C. They cannot be synthesized in a laboratory.

D. They interfere with viral replication in affected cells.

Which of the following minerals needed for bacterial reproduction do the liver and spleen sequester during a fever?

A. phosphorous and silica

B. iron and zinc

C. copper and gold

D. magnesium and calcium

Which hypersensitivity is caused by T lymphocytes?

A. chronic

B. delayed

C. subacute

D. acute

Which of the following is NOT a mechanism of antibody action?

A. precipitation

B. agglutination

C. B cell synthesis

D. neutralization

1) Which of the following is characteristic of antibodies?
A) carbohydrate structure
B) composed of heavy and light polypeptide chains
C) three binding sites per antibody monomer
D) incapable of being transferred from one person to another

2) Which of the following is associated with passive immunity?
A) exposure to an antigen
B) infusion of weakened viruses
C) passage of IgG antibodies from a pregnant mother to her fetus
D) booster shot of vaccine

3) Which of the following is not a type of T cell?
A) cytotoxic
B) antigenic
C) helper
D) regulatory

4) B lymphocytes develop immunocompetence in the ________.
A) thymus
B) spleen
C) bone marrow
D) lymph nodes

5) Which of the following is not a function of the inflammatory response?
A) prevents the spread of the injurious agent to nearby tissue
B) replaces injured tissues with connective tissue
C) disposes of cellular debris and pathogens
D) sets the stage for repair processes

6) The redness and heat of an inflamed area are due to a local hyperemia caused by ________.
A) vasodilation
B) vasoconstriction
C) phagocyte mobilization
D) production of complement and interferon

7) The antibody molecule is held together by ________ bonds.
A) disulfide
B) hydrogen
C) amino acid
D) sodium

8) In clonal selection of B cells, which substance is responsible for determining which cells will eventually become cloned?
A) antigen
B) interferon
C) antibody
D) complement

9) Which of the following statements regarding NK cells is a false or incorrect statement?
A) NK cells are a type of neutrophil.
B) NK cells are present in the blood, spleen, lymph nodes, and red bone marrow.
C) NK cells attack cells that display abnormal MHC antigens.
D) NK cells attack cancer cells and virus-infected body cells.

10) The process whereby neutrophils and other white blood cells are attracted to an inflammatory site is called ________.
A) diapedesis
B) chemotaxis
C) margination
D) phagocytosis

11) Small molecules that bind with self-proteins to produce antigenic substances are called ________.
A) haptens
B) antibodies
C) ions
D) reagins

12) Which of the following is the correct sequence of events in phagocytosis?
A) adherence, digestion, killing, ingestion, chemotaxis
B) chemotaxis, ingestion, digestion, adherence, killing
C) chemotaxis, adherence, ingestion, digestion, killing
D) ingestion, adherence, chemotaxis, digestion, killing

13) The only T cells that can directly attack and kill other cells are the ________.
A) regulatory cells
B) helper cells
C) cytotoxic cells
D) plasma cells

14) Which of the following does not respond to cell-mediated immunity?
A) intracellular pathogens that reside within host cells
B) some cancer cells
C) foreign tissue transplants
D) pathogens in the CNS

15) ________ predominate at the sites of chronic infections.
A) Basophils
B) Eosinophils
C) Macrophages
D) B cells

16) Interferons ________.
A) are virus-specific, so that an interferon produced against one virus could not protect cells against another virus
B) act by increasing the rate of cell division
C) interfere with viral replication within cells
D) are routinely used in nasal sprays for the common cold

17) ________ determine(s) what specific foreign substances our adaptive immune system will be able to recognize and resist.
A) The type of antigen
B) Memory cell production
C) Enzymes present at the time of the invasion
D) Our genes

18) Regulatory T cells ________.
A) release cytokines that increase the activity of cytotoxic T cells and activated B cells
B) decrease their activity as antigenic stimulus decreases
C) may function in preventing autoimmune reactions
D) are the most thoroughly understood T cells

19) Select the correct definition about tissue grafts.
A) Isografts are between identical twins.
B) Allografts are between different species.
C) Xenografts are between individuals of the same species.
D) Autografts are between two genetically identical individuals.

20) Which of the statements below does not describe antigens?
A) Antigens exhibit immunogenicity and reactivity.
B) Antigens only come from microbes.
C) The parts of antigen molecules that initiate immune responses are called epitopes or antigenic determinants.
D) Antigens can include proteins, nucleic acids, lipoproteins, glycoproteins, and certain large polysaccharides.

21) ________ are released by activated T cells and macrophages to mobilize immune cells and attract other leukocytes into the area.
A) Cytokines
B) Perforins
C) Interleukin 1 proteins
D) Interleukin 2 proteins

22) Which of the following is a part of the second line of defense against microorganisms?
A) keratin
B) cilia
C) gastric juice
D) phagocytes

23) Which of the following is characteristic of complete antigens?
A) small molecules
B) reactivity with an antibody
C) contain many repeating chemical units
D) inhibit production of antibodies

24) B cells respond to the initial antigen challenge by ________.
A) reducing its size
B) immediately producing antigen-specific antibodies
C) forming of a large number of cells that are unlike the original B cell
D) producing progeny cells that include plasma cells and memory cells

25) Graft rejection may be caused by ________.
A) using a xenograft
B) use of immunosuppressive drugs
C) treatment with antilymphocyte serum
D) total body irradiation

26) Cancer cells and virus-infected body cells can be killed before activation of adaptive immunity by ________.
A) natural killer cells
B) T lymphocytes
C) B lymphocytes
D) pinocytosis

27) Complement proteins and antibodies coat a microorganism and provide binding sites, enabling macrophages and neutrophils to phagocytize the organism. This phenomenon is termed ________.
A) diapedesis
B) agglutination
C) opsonization
D) chemotaxis

28) Which of the following is not characteristic of the adaptive immune system?
A) It is antigen-specific.
B) It is systemic.
C) It has memory.
D) It is specific for a given organ

29
29) Monoclonal antibodies are used for the diagnosis of all of the following except ________.
A) juvenile diabetes
B) hepatitis
C) rabies
D) pregnancy

30) Which of the following would be classified as a delayed hypersensitivity reaction?
A) immune complex hypersensitivity
B) anaphylaxis
C) cytotoxic hypersensitivity
D) allergic contact dermatitis

31) Innate immune system defenses include ________.
A) B cells
B) T cells
C) plasma cells
D) phagocytosis

32) Which of the following statements is incorrect or false?
A) Haptens lack immunogenicity unless attached to protein carriers.
B) Class 1 MHC molecules are built into the plasma membranes of all body cells.
C) 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.
D) MHC proteins are the cell’s identity markers.

33) Phagocyte mobilization involves ________.
A) diapedesis, during which cells line up against the capillary wall
B) margination, which is the process of white cell movement through the walls of capillaries into injured tissues
C) mainly neutrophil and macrophage migration into inflamed areas
D) monocytes as the most active phagocyte

33) Phagocyte mobilization involves ________.
A) diapedesis, during which cells line up against the capillary wall
B) margination, which is the process of white cell movement through the walls of capillaries into injured tissues
C) mainly neutrophil and macrophage migration into inflamed areas
D) monocytes as the most active phagocyte

35) Immunocompetence ________.
A) occurs in one specific organ of the adaptive immune system
B) is the ability of individual cells to recognize a specific antigen by binding to it
C) prevents intercellular communication so that only specific cell types respond to the invader
D) requires exposure to an antigen

36) Select the correct statement about the prevention of immune attack on "self."
A) The development of tolerance is specific to B cells only.
B) Neutrophils capable of binding to self-antigens are chemically inactivated.
C) Tolerance to self is due to the action of foreign antigens that inactivate the immune response to one's own tissues.
D) Tolerance is developed during fetal life.

37) Select the correct statement about active and passive immunity.
A) Immunological memory is established by passive immunization.
B) A vaccination is an example of the introduction of passive immunity into the body.
C) The antibodies utilized in active immunity are acquired from another organism.
D) Active and passive humoral immunity are both mechanisms of adaptive immunity that use antibodies.

) Cytotoxic T cells ________.
A) are the only T cells that can directly attack and kill other cells
B) require the double recognition signal of I MHC plus II MHC on the target cell in order to function
C) function mainly to stimulate the proliferation of other T cell populations
D) self-destruct once the antigen has been neutralized

39) Helper T cells ________.
A) bind tightly to target cells and release a lymphotoxin called perforin
B) often function to decrease the immune response
C) release B7 proteins
D) function in the adaptive immune system activation

40) Select the correct statement about immunodeficiency.
A) Severe combined immunodeficiency (SCID) disease is an acquired condition.
B) The causative agent in acquired immune deficiency syndrome (AIDS) is a virus that recognizes CD4 proteins.
C) Hodgkin's disease is a hereditary immunodeficiency found in children.
D) The most common form of immunodeficiency is graft-versus-host (GVH) disease.

41) Which of the following is true of immediate hypersensitivities?
A) They are also called type IV hypersensitivities.
B) They are are adaptive immune responses to disease organisms.
C) They include allergic contact dermatitis.
D) They involve IgE antibodies and the release of histamine from mast cells and basophils

42) Delayed hypersensitivities ________.
A) are mediated by B cells
B) include allergic contact dermatitis
C) include anaphylactic shock, a systemic vasodilation that results in inadequate blood delivery to all tissues
D) do not involve T cells

43) Natural killer (NK) cells ________.
A) are also called cytotoxic T cells
B) are a type of phagocyte
C) are cells of the adaptive immune system
D) can kill cancer cells before the immune system is activated

44) Select the correct statement about antigens.
A) "Self-antigens" is another name for incomplete antigens.
B) The largest type of antigen is called a hapten.
C) Only small antigens exhibit reactivity.
D) One antigen may have many different antigenic determinants and may therefore cause the formation of more than one antibody.

45) Clonal selection of B cells ________.
A) occurs during fetal development
B) results in the formation of plasma cells
C) cannot occur in the presence of antigens
D) only occurs in the secondary immune response

46) The primary immune response ________.
A) occurs more rapidly and is stronger than the secondary response
B) occurs when memory cells are stimulated
C) is another name for immunological memory
D) has a lag period while B cells proliferate and differentiate into plasma cells

47) Select the correct statement about the function of antibodies.
A) Antibodies may directly destroy "invaders."
B) Neutralization is the process by which antibodies cause invading cells to clump together.
C) Complement fixation is the main mechanism by which antibodies provide protection.
D) The most potent agglutinating agent is IgG.

48) Which of the following cells is the most critical cell in immunity?
A) B cell
B) helper T cell
C) cytotoxic T cell
D) APC

49) Which of the following is not an autoimmune disease?
A) multiple sclerosis
B) type II diabetes
C) systemic lupus erythematosus
D) glomerulonephritis

50) Which of the following is not a mechanism for the development of autoimmune disorders?
A) exposure of previously "hidden" self-antigens to the adaptive immune system
B) a second exposure to an allergen
C) mutation followed by the appearance of membrane proteins not previously present
D) cross-reaction of antibodies formed against foreign antigens with self-antigens

51) Select the correct statement about complement.
A) An adaptive immune mechanism is often involved in directing complement to its target.
B) Complement can be activated through three pathways: classical, secondary, and alternate.
C) The membrane attack complex consists of complement proteins C3a through C5.
D) Complement proteins C1 through C9 act exclusively in the classical pathway.

52) Which of the following is true about the number of binding sites per functional antibody unit?
A) IgD contains 4 binding sites.
B) IgA contains 6 binding sites.
C) IgG contains 6 binding sites.
D) IgM contains 10 binding sites

53) Antibody functions include all of the following except ________.
A) binding and inactivating chemical toxins released by bacteria or other microorganisms
B) cross-linking cell-bound antigens on red blood cells when blood types are properly matched
C) linking soluble antigens together so that they fall out of solution
D) targeting foreign cells so that complement proteins can cause cellular lysis

54) Which statement is true about T cells?
A) They usually directly recognize antigens, which then activates a subpopulation of killer cells.
B) Their proliferation is enhanced by interleukins 1 and 2.
C) Once activated, they cannot secrete cytokines.
D) They will develop into cytotoxic T cells if antigen is complexed with class II MHC proteins.

55) Toll-like receptors (TLRs) trigger the release of ________ to attract white blood cells to the scene.
A) cytokines
B) histamine
C) prostaglandins
D) complement

56) Which of the following is not a method by which antibodies work?
A) neutralizing antigen
B) activating cytokines
C) enhancing phagocytosis
D) agglutinating and precipitating antigen

57) What is the role of interferon in defense against disease?
A) protects cells that have not yet been infected by viruses
B) protects cells that have not yet been infected by bacteria
C) activates the complement mechanism
D) activates the inflammatory process

58) Which of the following statements is a false or incorrect statement?
A) The lymphoid organs where lymphocytes become immunocompetent are called primary lymph organs. All other lymphoid organs are referred to as secondary lymphoid organs.
B) It is our genes, not antigens, that determine what specific foreign substances our immune system will be able to recognize and resist.
C) After becoming immunocompetent, the naive T cells and B cells are exported to the bone marrow where the encounters with antigens occur.
D) T cells and B cells become fully immunocompetent when they bind with recognized antigens.