Chapter 21

Lymph originates in blood capillaries that pick up tissue fluid. True False

Red bone marrow is the point of origin of all immune cells of the lymphatic system. True False

Mucous membranes prevent most pathogens from entering the body because of the stickiness of the mucus and the presence of lysozymes. True False

Interferons are secreted in response to bacterial infections. True False

Pus is made of dead neutrophils, macrophages, and other tissue debris from a damaged tissue. True False

Pyrogens act by increasing the set point for body temperature in the thalamus. True False

The antigenicity of a molecule is due to specific regions of it called haptens. True False

Interleukins are chemical signals by which immune cells communicate with each other. True False

Helper T cells respond only to epitopes attached to MHC proteins. True False

Cytotoxic T cells respond only to antigens bound to MHC-I proteins. True False

Clonal selection of T cells happens in the thymus. True False

Naive T cells can synthesize antibodies. True False

Humoral immunity takes care of intracellular viruses, whereas cellular immunity takes care of extracellular viruses. True False

Memory B cells are found circulating mainly in the lymph. True False

Some antibodies against foreign antigens can react to similar self-antigens causing an autoimmune disease. True False

Lymphatic vessels recover about ______________ of the fluid filtered by capillaries. A. 5% B. 15% C. 25% D. 50% E. 85%

Lymph is similar to blood plasma, but very low in A. protein. B. carbon dioxide. C. metabolic waste. D. electrolytes. E. sodium and potassium.

Special lymphatic vessels called lacteals absorb dietary ______________ that are not absorbed by the blood capillaries. A. water B. glucose C. vitamins D. amino acids E. lipids

The ______________ tonsils are the largest, and their surgical removal (tonsillectomy) used to be one of the most common surgical procedures performed in children. A. adenoid B. lingual C. palatine D. pharyngeal E. nasopharyngeal

All these forces help lymph to flow except A. rhythmic contractions of lymphatic vessels. B. the thoracic pump. C. the skeletal muscle pump. D. the lymphatic node pump. E. arterial pulsations squeezing lymphatic vessels.

_____________ are the largest of the lymphatic vessels and they empty into the _______________. A. Lymphatic trunks; collecting ducts B. Lymphatic trunks; subclavian arteries C. Lymphatic trunks; subclavian veins D. Collecting ducts; subclavian veins E. Collecting ducts; subclavian arteries

Immune surveillance is a process in which ____________ nonspecifically detect and destroy foreign cells and diseased host cells. A. T lymphocytes (T cells) B. reticular cells C. dendritic cells D. macrophages E. natural killer (NK) cells

This organ shows a remarkable degree of degeneration (involution) with age. A. lymph node B. thymus C. spleen D. pharyngeal tonsil E. appendix

This is the only lymphatic organ with afferent lymphatic vessels. A. lymph node B. thymus C. spleen D. red bone marrow E. tonsils

Removal of the _________________ will be the most harmful of all for a one-year-old child. A. spleen B. lymph node C. thymus D. appendix E. palatine tonsil

All these belong to the second line of defense except A. the macrophage system. B. natural killer cells. C. inflammation. D. the gastric juices. E. interferon and the complement system.

______________ are found especially in the mucous membrane, standing guard against parasites and allergens. A. Monocytes B. Lymphocytes C. Basophils D. Neutrophils E. Eosinophils

___________ employ a "respiratory burst" to produce bactericidal chemicals such as hydrogen peroxide (H2O2) and hypochlorite (HClO). A. Neutrophils B. Basophils C. Cytotoxic T cells D. Natural killer cells E. Suppressor T cells

Complement fixation can lead to any of the following effects except A. enhanced inflammation. B. opsonization. C. endogenous pyrexia. D. bacterial phagocytosis. E. cytolysis.

________________ are secreted by cells infected with viruses, alerting neighboring cells and protecting them from becoming infected. A. Complement system globulins B. Interferons C. Granzymes D. Pyrogens E. Perforins

This figure shows A. the action of interferon. B. the action of the complement system. C. the action of a natural killer cell. D. immune clearance. E. opsonization.

A pyrogen is a substance that causes A. inflammation. B. opsonization. C. complement fixation. D. cytolysis. E. fever.

This is the first of a series of neutrophil behaviors in inflammation. A. chemotaxis B. margination C. diapedesis D. phagocytosis E. opsonization

_______________ is not a cardinal sign characteristic of inflammation. A. Impaired use B. Redness C. Pain D. Heat E. Swelling

Basophils of the blood help to get defensive leukocytes to the site quickly by releasing an anticoagulant called _____ and a vasodilator called ____________. A. bradykinin; histamine B. selectin; prostaglandin C. histamine; heparin D. heparin; histamine E. prostaglandins; selectin

All these cellular agents participate in inflammation except A. cytotoxic T cells. B. helper T cells. C. eosinophils. D. neutrophils. E. endothelial cells.

These are a group of proteolytic enzymes secreted by natural killer (NK) cells. A. selectins B. cytokines C. granzymes D. perforins E. interferons

Complement C3b protein coats bacteria and stimulates phagocytosis by ___________ in a process called _____________. A. lymphocytes and monocytes; opsonization B. neutrophils and macrophages; cytolysis C. mast cells and basophils; opsonization D. mast cells and basophils; cytolysis E. neutrophils and macrophages; opsonization

_________________ are antimicrobial proteins. A. Bradykinins B. Interferons C. Cytokines D. Kinins E. Prostaglandins

One characteristic of the immune response is specificity. This means that A. immunity starts in defined organs in the body. B. immunity starts in specialized tissues in the body. C. immunity is carried on by a specific group of cells of the immune system. D. immunity is directed against a particular pathogen. E. immunity is carried on by a specific group of tissues of the immune system.

Vaccination stimulates A. natural active immunity. B. artificial active immunity. C. natural passive immunity. D. artificial passive immunity. E. artificial specific immunity.

Cellular (cell-mediated) immunity is effective against A. allergens. B. venoms. C. cancer cells. D. extracellular viruses. E. toxins.

A(n) ______________ is the region of the molecule that is recognized by antibodies. A. epitope B. antigen C. hapten D. major histocompatibility complex (MHC) E. antibody monomer

T cells achieve immunocompetence in A. the bone marrow. B. the bloodstream. C. the spleen. D. the thymus. E. the liver.

T cells undergo positive selection in the thymus, which means A. they react against self antigens. B. they develop surface antigen receptors. C. they remain alive but unresponsive. D. self-reactive T cells die and macrophages phagocytize them. E. they multiply and form clones of identical T cells.

The serum used for emergency treatment of snakebites stimulates A. artificial passive immunity. B. artificial active immunity. C. natural passive immunity. D. natural active immunity. E. artificial specific immunity.

The majority of T cells of the naive lymphocyte pool wait for the encounter with foreign antigens in A. the plasma. B. the thymus. C. the lymphatic tissues. D. the lymph. E. most body fluids.

All of the following can act as antigen-presenting cells except A. reticular cells. B. dendritic cells. C. macrophages. D. B cells. E. T cells.

Helper T (TH) cells recognize antigens when they are bound to a(n) A. hapten. B. immunoglobulin. C. natural killer cell. D. major histocompatibility complex (MHC) protein. E. basophil.

Antigen-presenting cells usually display processed antigens to T cells in A. plasma. B. lymph nodes. C. thymus. D. red bone marrow. E. liver.

Helper T (TH) cells do not A. secrete cytokines that stimulate clonal selection of B cells. B. secrete cytokines that stimulate clonal selection of cytotoxic T cells. C. secrete cytokines that stimulate macrophage activity. D. secrete inflammatory chemicals. E. secrete fever-producing chemicals.

_____________________ participate in both nonspecific resistance and immune response. A. Memory T (TM) cells B. Regulatory T (TR) cells C. Natural killer (NK) cells D. Helper T (TH) cells E. Cytotoxic T (TC) cells

Cytotoxic T (TC) cells are like natural killer (NK) cells because they both A. secrete interferons. B. secrete granzymes and perforin. C. participate in the immune response. D. participate in nonspecific resistance. E. secrete tumor necrosis factor (TNF).

Memory T cells can live up to A. weeks. B. days. C. decades. D. years. E. months.

Antibodies do not A. link antigen molecules together. B. neutralize antigens by binding to regions of an antigen that can be pathogenic. C. bind to enemy cells, thus changing their shape so their complement-binding sites are exposed. D. differentiate into memory antibodies, which upon reexposure to the same pathogen would mount a quicker attack. E. bind antigen molecules of two or more enemy cells and stick them together.

This is the correct sequence of events in the humoral immune response. A. antigen recognition → antigen presentation → differentiation → clonal selection → attack B. antigen recognition → antigen presentation → clonal selection → differentiation → attack C. antigen presentation → antigen recognition → clonal selection → differentiation → attack D. antigen presentation → antigen recognition → clonal selection → attack differentiation E. antigen recognition → differentiation → antigen presentation → clonal selection → attack

Each immunoglobulin (Ig) has ______________ antigen-bonding site(s). A. two B. four C. six D. one E. three

_________________ constitutes about 80% of circulating antibodies in plasma. A. IgD B. IgE C. IgA D. IgM E. IgG

This is the class of immunoglobulin that provides passive immunity to the newborn. A. IgD B. IgE C. IgM D. IgA E. IgG

Before B cells secrete antibodies they differentiate into A. stem cells. B. antigen-presenting cells. C. plasma cells. D. T cells. E. macrophages.

The human immunodeficiency virus (HIV) targets mainly A. helper T cells. B. B cells. C. plasma cells. D. cytotoxic T cells. E. natural killer cells.

Most common allergies are the result of A. autoimmune diseases. B. type IV (delayed) hypersensitivity. C. type III (immune complex) hypersensitivity. D. type II (antibody-dependent cytotoxic) hypersensitivity. E. type I (acute) hypersensitivity.

Beta cell destruction that causes type 1 diabetes mellitus is a(n) A. anaphylactic hypersensitivity. B. type IV (delayed) hypersensitivity. C. type III (immune complex) hypersensitivity. D. type II (antibody-dependent cytotoxic) hypersensitivity. E. type I (acute) hypersensitivity.

A person who is HIV-positive and has a helper T (TH) cells count lower than ____________ has AIDS. A. 20,000 cells/μL B. 5,000 cells/μL C. 1,000 cells/μL D. 200 cells/μL E. 50 cells/μL

Autoimmune diseases are disorders in which the immune system fails to distinguish ____________ from foreign ones. A. self-immunoglobulins B. self-antibodies C. self-antigens D. self-interleukins E. self-complement proteins