ch 22

All of the following are true of the primary response of humoral immunity, except that it A) is delayed by the memory cell stage. B) depends on antigen triggering the appropriate B cell. C) requires B cell differentiation into plasma cells. D) peaks 1 to 2 weeks after the initial exposure. E) circulating antibodies undergo a gradual, sustained rise.

A

Class II MHC proteins are present in the plasma membrane only A) when NK cells are activated. B) in antigen-presenting cells and lymphocytes. C) when cytotoxic T cells are inhibited. D) when plasma cells are releasing antibodies. E) during infections.

B

Compared to blood capillaries, lymph capillaries exhibit all of the following, except that they A) have no basement membrane. B) are smaller in diameter. C) are frequently irregular in shape. D) are larger in diameter. E) have walls of endothelial cells that overlap like shingles.

B

During a primary humoral response to antigens all of the following occur, except A) B cells may differentiate into plasma cells immediately. B) neutrophils invade the surrounding areas, releasing chemotactic substances. C) the first immunoglobulins to appear in circulation are of the IgM type. D) antibody levels do not peak until 1 to 2 weeks after the initial exposure. E) B cells may undergo several rounds of mitosis before producing plasma cells and memory cells.

B

Each IgG has ________ binding sites for attachment to antigenic determinants. A) 1 B) 2 C) 4 D) up to 8 E) as many as a 1000

B

If the thymus shrank and stopped making thymosins, we would expect to see an immediate decrease in the number of A) B lymphocytes. B) T cells. C) neutrophils. D) NK cells. E) both B and C

B

Lymphatic vessels are located in almost all portions of the body, except the A) renal arteries. B) CNS. C) groin. D) periphery. E) throat.

B

Lymphocytes A) are primarily found in red bone marrow. B) respond to antigens. C) are actively phagocytic. D) destroy red blood cells. E) decrease in number during infection.

B

Lymphoid tissue is found in the greatest quantity in A) the tonsils. B) the adult spleen. C) bone marrow. D) Peyer patches. E) the adult thymus.

B

Most of the lymph returns to the venous circulation by way of the A) right lymphatic duct. B) thoracic duct. C) cisterna chyli. D) dural sinus. E) hepatic portal vein.

B

T cells and B cells can be activated only by A) interleukins, interferons, and colony-stimulating factors. B) exposure to a specific antigen at a specific site in a plasma membrane. C) disease-causing agents. D) pathogens. E) cells infected with viruses, bacteria, or cancer cells.

B

T is to ________ as B is to ________. A) non-thymus-dependent; bottom B) thymus-dependent; bone marrow-derived C) thyroid; bowel D) top; bottom E) none of the above

B

The cells directly responsible for cellular immunity are the ________ cells. A) helper T B) cytotoxic T C) B D) plasma E) suppressor T

B

The effects of activating the complement system include all of the following, except A) stimulation of inflammation. B) inhibition of the immune response. C) opsonization. D) destruction of target cell plasma membranes. E) chemotaxis.

B

The first line of cellular defense against pathogens are the A) B cells. B) phagocytes. C) T cells. D) plasma cells. E) NK cells.

B

The largest single collection of lymphoid tissue in the adult body is located in the A) tonsils. B) spleen. C) lymph nodes. D) thymus. E) liver.

B

The lymphoid system is composed of all of the following, except A) lymph nodes. B) the venae cavae. C) the spleen. D) lymphatic vessels. E) lymph.

B

The only antibodies that normally cross the placenta are A) IgE. B) IgG. C) IgA. D) IgM. E) IgD.

B

The primary function of the lymphoid system is A) the transport of hormones. B) defending the body against both environmental hazards and internal threats. C) the production and distribution of plasma proteins. D) circulation of nutrients. E) both B and D

B

When an antigen is bound to a Class I MHC molecule, it can stimulate a ________ cell. A) B B) cytotoxic T C) helper T D) plasma E) NK

B

Which class of leucocytes is particularly abundant in the red pulp of the spleen? A) T lymphocytes. B) free and fixed macrophages. C) B lymphocytes. D) red blood cells. E) neutrophils.

B

Which of these statements about lymph flow in a node is false? A) lymph first enters the subcapsular space B) the afferent lymphatics enters at the hilum C) the efferent lymphatic exits at the hilum D) lymph flows past dendritic cells E) lymph enters in an afferent lymphatic

B

________ is the class of antibody first secreted in response to a new antigen. A) IgG B) IgM C) IgE D) IgD E) IgA

B

An inflammatory response is triggered when A) blood flow to an area increases. B) T cells release interferon. C) mast cells release histamine and heparin. D) neutrophils phagocytize bacteria. E) red blood cells release pyrogens.

C

Cells that help regulate the immune response are ________ cells. A) plasma B) NK C) helper T D) cytotoxic T E) B

C

Class II MHC molecules are found only on which of the following? A) red blood cells B) all body cells with a nucleus C) lymphocytes and antigen-presenting cells D) granulocytes and microphages E) liver cells and macrophages in the spleen

C

Immunity that results from antibodies that pass the placenta from mother to fetus is called ________ immunity. A) active B) passive C) naturally acquired passive D) innate E) auto

C

Immunoglobulins that are primarily found in glandular secretions such as saliva and tears are A) IgG. B) IgD. C) IgA. D) IgE. E) IgM.

C

Inappropriate or excessive immune responses to antigens are A) signs of a weak system. B) autoimmune diseases. C) allergies. D) the result of stress. E) immunodeficiency diseases.

C

Interleukins do all of the following, except A) elevate body temperature. B) stimulate B-cell activity, plasma cell formation, and antibody production. C) stimulate collagen synthesis. D) stimulate inflammation. E) increase T-cell sensitivity to antigens exposed on macrophage membranes.

C

Lymphatic vessels commonly occur in association with A) adipose tissue. B) hyaline cartilage. C) blood vessels. D) sensory nerve endings. E) both A and C

C

Lymphoid organs differ from lymphoid tissues in what way? A) They cannot produce antibodies, whereas lymphoid tissues can. B) They are found in the digestive tract and lymphoid tissues are found in the thorax. C) They are surrounded by a fibrous capsule and lymphoid tissues are not. D) They contain T lymphocytes and lymphoid tissues do not. E) both A and B

C

Suppressor T cells act to A) erase memory T cells. B) limit antigen proliferation. C) inhibit T and B cell activities. D) produce antibodies involved in autoimmunity. E) suppress antigens.

C

The body's nonspecific defenses include all of the following, except A) complement. B) inflammation. C) antibodies. D) interferon. E) the skin.

C

The merging of ________ forms the right lymphatic duct. A) the thoracic and mediastinal ducts B) superior and inferior lymphatic ducts C) the right jugular, right subclavian, and right bronchomediastinal trunks D) two great vessels E) the left jugular, right subclavian, and right bronchomediastinal trunks

C

The term lymphadenopathy refers to A) increased numbers of circulating lymphocytes. B) a congenital lack of lymph nodes. C) a chronic or excessive enlargement of lymph nodes. D) the lack of lymphocytes in peripheral circulation. E) accumulations of lymph in the tissue space.

C

The thoracic duct drains lymph from all of the following regions, except the A) left breast. B) left side of neck. C) right breast. D) pelvic viscera. E) left arm and shoulder.

C

Which of the following interleukins stimulates T cells to produce IL-2, promotes inflammation, and causes fever? A) IL-3 B) IL-8 C) IL-1 D) IL-4 E) both A and D

C

Which of these is not a property of an IgG heavy chain? A) binds complement in the constant region B) has one variable segment C) binds antigen at both ends D) binds one light chain E) has one constant segment

C

The lymphoid system does all of the following, except that it A) fights infection. B) eliminates variations in the composition of interstitial fluid. C) transports lipids from the digestive tract. D) helps maintain normal blood volume. E) transports gases to and away from lymph nodes.

E

The role of antigen-presenting cells in immunity is to A) process antigens. B) activate T cells. C) display antigen fragments. D) produce antibodies. E) A, B, and C

E

When an antigen is bound to a Class II MHC protein, it can activate a ________ cell. A) NK B) plasma C) suppressor T D) cytotoxic T E) helper T

E

Which of the following statements about MHC proteins is not true? A) are found on all nucleated cells B) fall into two major classes C) function in antigen presentation D) allow the body to differentiate its own cells from foreign cells E) bind complement

E

The cells responsible for the production of circulating immunoglobulins are ________ cells. A) NK B) liver C) thymus D) plasma E) helper T

D

The cells that perform immunological surveillance are the ________ cells. A) suppressor T B) B C) plasma D) NK E) helper T

D

The classic pathway of complement activation begins when the protein C1 binds to A) the cell wall of bacteria. B) a plasma protein. C) the plasma membrane of bacteria. D) an antibody attached to an antigen. E) a cell surface antigen.

D

The release of endogenous pyrogen (or interleukin-1) by active macrophages would A) opsonize pathogens. B) cause inflammation. C) activate antibodies. D) produce a fever. E) activate complement.

D

________ are clusters of lymphoid nodules deep to the epithelial lining of the small intestine. A) Tonsils B) Lymph glands C) Immune complexes D) Peyer patches E) Adenoids

D

The largest collection of lymphoid tissue in the body is found in the A) pancreas. B) kidney. C) liver. D) thyroid gland. E) spleen.

E

All of the following are true of the secondary response of humoral immunity, except that it A) weakens quickly because memory B cells only survive for a year or two. B) produces more effective antibodies. C) results in much higher antibody titers than in the primary response. D) depends on memory B cells. E) results in much quicker rise in antibody titers.

A

Helper T cells do all of the following, except A) provide a rapid response to a future exposure to the antigen. B) trigger B-cell division, plasma cell maturation, and antibody production. C) attract and stimulate the activity of NK cells. D) enhance production of memory and cytotoxic T cells. E) enhance nonspecific defenses.

A

Hormones of the immune system include all of the following, except A) tumor necrosis factor. B) interferons. C) interleukins. D) natriuretic factor. E) thymosins.

A

If the disulfide bonds in IgG were broken, how many protein chains would be set free? A) 4 B) 8 C) 2 D) 6 E) dozens

A

Immunity that is genetically determined and present at birth is called ________ immunity. A) innate B) natural passive C) passive D) auto E) active

A

Immunity that results from exposure to an antigen in the environment is called ________ immunity. A) naturally acquired active B) natural passive C) auto D) innate E) passive

A

Lymph nodes do all of the following, except that they A) remove excess nutrients from the lymph. B) accumulate cancer cells. C) produce antibodies. D) remove debris and pathogens from the lymph. E) monitor the contents of lymph.

A

Lymphocytes that destroy foreign cells or virus-infected cells are ________ cells. A) cytotoxic T B) plasma C) helper T D) B E) suppressor T

A

Stem cells that will form B cells or NK cells are found only in the A) bone marrow. B) liver. C) spleen. D) kidneys. E) thymus.

A

Stress can affect the immune response in all of the following ways, except by A) inhibiting glucocorticoid release. B) reducing the number of phagocytes. C) depressing the inflammatory response. D) inhibiting interleukin secretion. E) increasing the level of glucocorticoids.

A

The cells responsible for humoral immunity are the ________ cells. A) B B) suppressor T C) cytotoxic T D) NK E) helper T

A

The following are steps in the cell-mediated immune response. 1. Several cycles of mitosis occur. 2. Antigen is engulfed and presented by a macrophage. 3. Cytotoxic T cells migrate to focus of infection. 4. T cells with specific receptors recognize the antigen. 5. T cells differentiate into cytotoxic T cells or T memory cells. 6. Cytotoxic T cells release perforin and/or lymphotoxin. The correct sequence for these steps is A) 2, 4, 1, 5, 3, 6. B) 3, 6, 4, 5, 1, 2. C) 3, 2, 4, 1, 5, 6. D) 1, 2, 4, 5, 3, 6. E) 4, 1, 5, 3, 6, 2.

A

The medullary cords of a lymph node contain ________ lymphocytes and plasma cells. A) B B) NK C) cordal D) cytotoxic T E) medullary

A

The various classes of immunoglobulins are differentiated on the basis of their A) heavy-chain constant segments. B) light-chain variable segments. C) asymmetry. D) antigen specificity. E) both C and D

A

The white pulp of the spleen is populated by A) lymphocytes. B) veins. C) fibrous connective tissue. D) trabeculae. E) arteries.

A

Various types of macrophages are derived from A) monocytes. B) eosinophils. C) neutrophils. D) lymphocytes. E) basophils.

A

________ are large lymphoid nodules that are located in the walls of the pharynx. A) Tonsils B) Lymph nodes C) Immune complexes D) Peyer patches E) Spleens

A

All of the following are true of the thymus gland, except that it A) involutes after puberty. B) lies in the anterior mediastinum. C) produces T cells. D) activates B cells. E) reaches its greatest relative size during the second year of life.

D

B cells are primarily activated by the activities of A) antibodies. B) antigens. C) macrophages. D) helper T cells. E) plasma cells.

D

Defense of the body against a particular pathogen is provided by A) immunological surveillance. B) nonspecific immunity. C) fever. D) specific immunity. E) skin defenses.

D

Dividing lymphocytes can be found in the ________ of the lymphoid nodule. A) central zone B) germinal center C) cortex D) both A and B E) A, B, and C

D

Each of the following is a physical barrier to infection, except A) basement membranes. B) secretions. C) body hair. D) complement. E) epithelium.

D

Immunoglobulins that attach to and sensitize mast cells and basophils are A) IgA. B) IgD. C) IgG. D) IgE. E) IgM.

D

Immunoglobulins, formed of five subunits, that are the first antibodies to be produced in response to infection, are A) IgD. B) IgG. C) IgE. D) IgM. E) IgA.

D

In IgG, the antigen binding site is formed by A) the variable segment of the light chain B) the constant segment of the heavy chain C) the variable segment of the heavy chain D) A + B E) A + C

D

In order for a lymphocyte to respond to an antigen, the antigen must A) be phagocytized by the lymphocyte. B) bind to the DNA of the lymphocyte. C) enter the cytoplasm of the lymphocyte. D) bind to specific receptors on the lymphocyte surface. E) depolarize the lymphocyte.

D

Lymph nodes range in diameter from A) 1 cm to 1 inch. B) 1 nm to 10 nm. C) 1 inch to 2 inches. D) 1 mm to 25 mm. E) 1 cm to 25 cm.

D

Lymphocyte production involves A) bone marrow. B) peripheral lymphoid tissues. C) thymus tissue. D) all of the above E) A and B only

D

Plasma contains ________ special complement proteins that form the complement system. A) 3 B) 9 C) 5 D) 11 E) 7

D

Specific defenses depend on the activities of A) monocytes. B) leukocytes. C) agranulocytes. D) lymphocytes. E) erythrocytes.

D

Stem cells that can form all types of lymphocytes are concentrated in the A) spleen. B) circulation. C) thymus. D) red marrow. E) yellow marrow.

D

Stem cells that will form T cells develop in the A) spleen. B) liver. C) kidneys. D) thymus. E) bone marrow.

D

The binding of an antigen to an antibody can result in A) complement activation and opsonization. B) agglutination or precipitation. C) neutralization of the antigen. D) all of the above E) A and B only

D

Areas of the spleen that contain large aggregations of lymphocytes are known as A) red pulp. B) lymph nodes. C) adenoids. D) Peyer patches. E) white pulp.

E

Autoantibodies A) are the first step in immunological competence. B) are produced by activated T cells. C) are produced during an allergic reaction. D) are important in tissue rejection reactions. E) are directed against the body's own antigens.

E

Changes in the immune system that accompany aging include A) B cells less responsive. B) decreased numbers of T helper cells. C) fewer cytotoxic T cells responding to infections. D) T cells becoming less responsive to antigens. E) all of the above

E

Characteristics of specific defenses include A) specificity. B) tolerance. C) versatility. D) memory. E) all of the above

E

Examples of physical barriers against pathogens include A) epithelia. B) sebaceous glands. C) mucus. D) epidermal layers. E) all of the above

E

Fever is the maintenance of body temperature greater than A) 37.2ÅãC. B) 99ÅãF. C) 98.6ÅãF. D) A or C E) A or B

E

Immunoglobulins that are found on the surface of B cells and may activate antibody production are A) IgM. B) IgE. C) IgA. D) IgG. E) IgD.

E

Immunoglobulins that are most abundant and are responsible for resistance against many viruses, bacteria, and bacterial toxins are A) IgA. B) IgD. C) IgM. D) IgE. E) IgG.

E

In general, lymphocytes A) spend most of their time in lymphoid tissue. B) have relatively long life spans. C) have two nuclei. D) all of the above E) A and B only

E

In passive immunization, the A) immune system attacks normal body cells. B) body is deliberately exposed to an antigen. C) body receives antibodies produced by other humans. D) body receives antibodies produced by an animal. E) either C or D

E

Inflammation produces localized A) pain. B) heat. C) redness. D) swelling. E) all of the above

E

Lymphatic capillaries are known for A) being the starting point of the lymphatic circulation. B) being the smallest lymphatic vessels. C) shingle-like endothelial cells. D) having larger diameters and looser walls than blood capillaries. E) all of the above

E

Lymphocytes are produced and stored in all of the following, except A) the spleen. B) lymph node organs. C) lymphoid nodules. D) the thymus. E) the brain.

E

Lymphocytes may be found in which of the following tissues or organs? A) lymph nodes B) tonsils C) spleen D) thymus E) all of the above

E

Microphages include A) Kupffer cells. B) monocytes. C) neutrophils. D) eosinophils. E) both C and D

E

Newborns gain their immunity initially from A) contact with viruses and bacteria. B) contact with siblings. C) early immunizations. D) breast milk. E) antibodies passed across the placenta from the mother.

E

Nonspecific defenses include A) phagocytic cells. B) interferons. C) inflammation. D) physical barriers. E) all of the above

E

The cell that dominates the deep cortical region of a lymph node is the ________ cell. A) NK B) plasma C) B D) nodule E) T

E