PHYSIOLOGY CHP 18 MC

B cells that differentiate during an initial immune response but remain dormant until being activated during a subsequent exposure to an antigen are called: A. T cells. B. memory cells. C. macrophages. D. monocytes. E. cytokines.

B

The killing of cancerous cells by the immune system is called: A. immune oversight. B. immune surveillance. C. tissue immunity. D. phagocytosis. E. hemostasis.

B

Which of the following is NOT normally a route of transmission of HIV/AIDS? A. unprotected sexual intercourse with an infected partner B. kissing or contact with items contaminated by the saliva of an infected individual C. across the placenta from an infected mother to her fetus during pregnancy or delivery D. via breast milk during nursing E. transfer of contaminated blood or blood products from one person to another

B

Which of the following statements regarding blood-type incompatibilities between a mother and her fetus is TRUE? A. An Rh-negative fetus may be at risk if its mother is Rh-positive. B. An Rh-positive fetus may be at risk if its mother is Rh-negative. C. A fetus with type B blood may be at risk if its mother has type O blood. D. The risk to an Rh-positive fetus of an Rh-negative mother is lessened if she has previously carried an Rh-negative fetus. E. The greatest risk to a fetus occurs when both mother and fetus are Rh-positive.

B

Which of the following statements regarding phagocytosis is TRUE? A. Macrophages are the only phagocytes in the tissues. B. The microbe engulfed by the phagocyte is killed by lysosomal enzymes and hydrogen peroxide. C. Phagocytosis is controlled by a negative feedback mechanism whereby phagocytes release chemicals that inhibit further phagocytosis. D. The microbe engulfed by the phagocyte is killed by the membrane attack complex (MAC). E. Antibodies found inside lysosomes attack and kill microbes that are engulfed by phagocytosis.

B

Which of the following statements regarding the secretions of immune system cells is TRUE? A. Type 2 interferons are only secreted by macrophages. B. Interleukin 2 is a cytokine secreted by most immune cells. C. Type 1 interferons are also called interferon-gamma. D. Colony-stimulating factors are secreted mainly by plasma cells. E. Antibodies are produced and secreted by macrophages.

B

Chemotaxis: A. refers to the chemical attraction of neutrophils to a site of inflammation. B. is important only for innate immune responses. C. is important only for adaptive immune responses. D. refers to the engulfing of microbes and foreign molecules by macrophages. E. refers to dilation of blood vessels by chemicals released by damaged tissue cells.

A

Colony-stimulating factors are produced by ________________ and target cells in the _____________________, which results in _______________. A. macrophages; bone marrow; stimulation of proliferation of neutrophils and monocytes B. B cells; thymus; conversion of B cells to T cells C. NK cells; blood vessel walls; vasodilation D. monocytes; blood vessel walls; vasoconstriction E. basophils; bone marrow; release of histamine

A

Helper T cells: A. are activated by antigen presented with MHC II proteins. B. secrete antibodies that target specific antigens. C. secrete perforin when activated. D. convert to plasma cells after they are activated. E. do not interact with MHC proteins.

A

Natural killer cells: A. are activated by IL-2 and interferon-gamma. B. only attack bacteria. C. cannot interact with antibodies. D. secrete interferon-gamma to activate helper T-cells. E. have primary responsibility for mass-manufacturing antibodies against foreign antigens.

A

Which is NOT an example of an autoimmune disease? A. AIDS B. multiple sclerosis C. myasthenia gravis D. rheumatoid arthritis E. type 1 diabetes mellitus

A

Which is NOT true about viruses? A. They consist of a nucleic acid surrounded by a carbohydrate shell. B. They require a host cell in order to reproduce themselves. C. They may reside in a host cell for years without killing it. D. They may cause a host cell to become cancerous. E. They may have genetic information in the form of RNA.

A

Which of the following statements about the immune system is TRUE? A. Neutrophils, basophils, eosinophils, and monocytes originate in bone marrow. B. Natural killer cells produce specific antibodies that kill bacteria and viruses. C. Mast cells are derived from monocytes. D. Plasma cells are derived from T lymphocytes. E. Macrophages are derived from neutrophils.

A

Which of the following statements regarding major histocompatibility proteins (MHCs) is TRUE? A. Class I MHCs are found on all cells of the body except erythrocytes. B. Class II MHCs are normally found in the cell membranes of bacteria. C. Cytotoxic T cells require class II MHCs to recognize foreign antigens. D. All humans have identical sets of MHC proteins. E. MHC proteins are the same thing as antibodies.

A

Antibodies are: A. secreted by helper T cells. B. cytokines. C. immunoglobulins. D. composed of two polypeptide chains - a heavy chain and a light chain. E. phagocytes.

C

Cytotoxic T cells: A. secrete perforin, which kills bacteria and viruses by perforating the membrane or coat that surrounds them. B. are activated by interleukin 1. C. require Class I MHC proteins to recognize foreign antigens. D. are converted to plasma cells when activated by MHC proteins. E. secrete proteins that neutralize bacterial toxins.

C

When an antigen is bound to an antibody, it binds to: A. the heavy immunoglobulin chain only. B. the light immunoglobulin chain only. C. a specific antigen-binding site formed by heavy and light chains. D. a hypervariable region of immunoglobulin DNA. E. gamma immunoglobulin only.

C

Which class of antibodies are commonly called gamma globulin? A. IgM B. IgE C. IgG D. IgA E. IgD

C

Which is TRUE regarding the immune system cells? A. Plasma cells are derived from T cells. B. Macrophages are derived from basophils. C. Macrophages are derived from monocytes. D. The immune cells found within the bloodstream are called erythrocytes. E. Neutrophils are classified as lymphoid cells.

C

Which is normally present in a subject with type O blood? A. erythrocytes carrying type A antigen B. erythrocytes carrying type B antigen C. both anti-A and anti-B antibodies in the plasma D. erythrocytes with both type A antigen and type B antigen E. plasma that has neither anti-A nor anti-B antibodies

C

Which of the following cell types binds to antigens on plasma membranes of target cells and directly destroys the cells? A. neutrophils B. NK cells C. cytotoxic T cells (CD8 cells) D. helper T cells (CD4 cells) E. B cells

C

Which of these correctly describes a systemic response to infection? A. Appetite generally increases compared to normal. B. The body's set point temperature is reset so that body temperature is maintained lower than normal. C. The liver retains iron and zinc so plasma levels are decreased from normal. D. There is reduced breakdown of triglycerides in adiopse tissue and a decrease in plasma free fatty acids compared to normal. E. Secretion of cortisol by the adrenal cortex is decreased.

C

After initial entry of bacteria into a cut in the skin, vasodilation of local blood vessels and increased capillary permeability occur. Which of the following events is NOT part of the adaptive immune response to the infection? A. antigen interaction with lymphocytes B. production of antibodies that bind to antigens C. B-cell differentiation into plasma cells D. vasodilation of local blood vessels E. activation of lymphocytes

D

Cells of the immune system capable of phagocytosis include: A. macrophages, NK cells, and basophils. B. B cells, T cells, and macrophages. C. monocytes, neutrophils, and plasma cells. D. macrophages, neutrophils, and dendritic cells. E. macrophages, mast cells, and lymphocytes.

D

Individuals who have been infected by the human immunodeficiency virus (HIV): A. always manifest symptoms early in the disease process. B. can be diagnosed only when they develop certain rare forms of cancer. C. succumb to the disease in a relatively brief period of time after infection due to massive loss of T lymphocytes. D. generally are diagnosed by detection of anti-HIV antibodies or HIV RNA in their blood. E. have normal B-cell and cytotoxic T-cell function.

D

The rationale behind the drugs used to treat HIV/AIDS is to reduce the number of viruses present in the body to infect otherwise healthy cells. Which of these is NOT a therapy that acts in this way? A. inhibition of the reverse transcriptase enzyme B. interference with the processes involved in expression of viral nucleic acid by the host cell C. blocking an alpha protease enzyme associated with the assembly of the virus D. chemical agents directed at interruption of mitosis in host cells for the virus E. blocking the attachment and fusion of the HIV viruses with T lymphocyte hos

D

What two cell types are mainly responsible for graft rejection? A. B cells and helper T cells B. natural killer cells and B cells C. marcrophages and natural killer cells D. cytotoxic T cells and helper T cells E. B cells and plasma cells

D

Which applies to the classical complement pathway, but NOT to the alternative complement pathway? A. Activation of C3 results in the formation of C3b. B. There is a cascade of proteins activated, which results in the killing of microbes. C. Complement proteins serve as opsonins that facilitate phagocyte binding to microbes. D. Antibodies activate the first complement protein (C1). E. Complement activation leads to the development of a multiunit protein called the membrane attack complex (MAC).

D

Which does NOT accurately describe interferons? A. They are proteins produced by most cells of the body in response to infection by a virus. B. They interfere with viral replication in cells. C. They play a role in the killing of tumor cells. D. They kill bacteria by forming pores in the cell membrane. E. They bind to surface receptors on cells, and trigger cellular production of antiviral proteins.

D

Which of the following statements regarding complement is FALSE? A. Certain complement proteins are always circulating in the blood in an inactive state. B. Activated complement can form a membrane attack complex, which forms pores in microbe membranes. C. Activated complement can stimulate cells to secrete inflammation-mediating chemicals. D. The complement pathway is always dependent upon activation of the first complement protein, C1. E. Some activated complement proteins activate other complement proteins.

D

Which of the following statements regarding the chemical mediators of inflammatory responses is NOT true? A. They may be secreted by cells residing in the area of injury. B. They may be secreted by cells that enter the affected area. C. They may be generated by enzymatic cleavage of proteins in plasma. D. They are all peptides. E. They may be chemotaxins.

D

Which type of allergy/hypersensitivity occurs independent of antibodies? A. immune-complex hypersensitivity B. immediate hypersensitivity C. cytotoxic hypersensitivity D. delayed hypersensitivity

D

After activation of C3 of the complement system, which of these is a role of its component part, C3b? A. It acts as an enzyme to convert nitric oxide into hydrogen peroxide. B. It causes vasodilation of local blood vessels. C. It acts as a chemotaxin for macrophages. D. It stimulates the conversion of monocytes to neutrophils. E. It acts as an opsonin that is recognized by phagocytes targeting the microbe for destruction.

E

After phagocytosis of a microbe, vesicles called phagosomes combine with intracellular organelles called ________________, resulting in destruction of the microbe. A. autosomes B. ribosomes C. nucleosomes D. mitochondria E. lysosomes

E

The immune system destroys or neutralizes: A. bacteria. B. viruses. C. nonmicrobial foreign substances. D. cancer cells that arise in the body. E. All of the choices are correct.

E

Which is NOT a function performed by activated macrophages? A. They perform phagocytosis. B. They secrete cell-killing chemicals. C. They present antigens to T-cells. D. They secrete cytokines involved in inflammation. E. They produce antibodies that bind to specific antigens.

E

Which is NOT true about AIDS? A. It is caused by a retrovirus. B. It is caused by a virus that contains RNA. C. It is transmitted by intimate contact with infected blood, sexual intercourse with an infected partner, or by an infected mother to her fetus or breast-fed infant. D. Certain unusual cancers such as Kaposi's sarcoma co-occur with relatively high frequency. E. The HIV virus preferentially enters and disables B cells.

E

Which is NOT true regarding antibodies? A. They are secreted by plasma cells. B. They protect against viruses by binding to them and presenting them to phagocytes. C. They protect against viruses by binding to them and neutralizing them. D. They activate complement. E. They are the main mediators of the innate immune response.

E

Which of the following is NOT a systemic effect of IL-1 and other cytokines in response to infection or tissue injury? A. increased plasma levels of amino acids B. increased secretion of colony-stimulating factors C. decreased appetite D. secretion of acute-phase proteins by the liver E. stimulation of helper T cells

E

Which of the following statements regarding the lymphoid organs is NOT true? A. The primary lymphoid organs are the bone marrow and thymus. B. The thymus secretes protein hormones, collectively called thymopoietins. C. Large numbers of macrophages and lymphocytes are found in the lymph nodes and spleen. D. The tonsils contain lymphocytes, macrophages, and dendritic cells that respond to microbes in food. E. Once a lymphocyte reaches a secondary lymphoid organ, it remains there for its lifetime.

E

Which of the following statements regarding phagocytes and phagocytosis is true? A. Macrophages, monocytes, and mast cells are phagocytes. B. Contact of phagocytes with microbes stimulates the phagocytes to release chemicals that mediate the inflammatory response. C. Phagocytosis is stimulated by the presence of proteins called rhodopsins. D. Phagocytosis is the process by which leukocytes exit the bloodstream. E. Phagocytosis is a process that only occurs within the bloodstream.

b