Anatomy and Physiology: Chapter 20

Antigen presentation occurs when an antigen-glycoprotein complex capable of activating T cells appears in a plasma membrane. Place the steps in the correct order to outline how most body cells find and present antigens.

-Body cell becomes infected by a virus or bacterium -Abnormal peptides appear in the cytoplasm -The endoplasmic reticulum incorporates abnormal peptides as it synthesizes Class I MHC -The Golgi apparatus packages Class I MHC into secretory vesicles -Class I MHC displays abnormal peptides on the plasma membran

Which statement regarding CD4 T cells is true? -Upon activation, CD4 T cells undergo a series of divisions, and daughter cells differentiate into active cytotoxic T cells and suppressor T cells. -A CD4 T cell can recognize antigens bound to Class I MHC proteins. -Prior to differentiating into an active helper T cell, a CD4 T cell must first encounter a suppressor T cell. -Before they can initiate antibody-mediated immunity, inactive CD4 T cells must be exposed to appropriate antigens bound to Class II MHC proteins.

Before they can initiate antibody-mediated immunity, inactive CD4 T cells must be exposed to appropriate antigens bound to Class II MHC proteins.

Lymphocytes that destroy foreign cells or virus-infected cells are ________ cells. -suppressor T -helper T -plasma -B -cytotoxic T

cytotoxic T

The primary function of the lymphatic system is -the transport of hormones. -the production and distribution of plasma proteins. -defending the body against both environmental hazards and internal threats. -circulation of nutrients. -both the transport of hormones and the production and distribution of plasma proteins.

defending the body against both environmental hazards and internal threats.

Helper T cells do all of the following except -secrete cytokines to stimulate production of plasma cells. -destroy target cells using perforins. -activate sensitized B cells by costimulation. -enhance antibody-mediated immunity. -enhance cell-mediated immunity.

destroy target cells using perforins

The movement of phagocytes through the capillary wall is called -phagocytosis. -apoptosis. -chemotaxis. -diapedesis. -involution.

diapedesis.

Which class of leukocytes is particularly abundant in the red pulp of the spleen? -T lymphocytes -neutrophils -B lymphocytes -free and fixed macrophages -red blood cells

free and fixed macrophages

Cells that help regulate the antibody-mediated immune response are ________ cells. -B -NK -helper T -plasma -cytotoxic T

helper T

B cells are primarily activated by the activities of -antigens. -antibodies. -helper T cells. -macrophages. -plasma cells.

helper T cells.

Which property of immunity exists because cell divisions of activated lymphocytes produce two groups of cells? -immunologic memory -tolerance -specificity -versatility

immunologic memory

Which of the following is NOT a possible result of antigen presentation? -destruction of pathogens -antibody production -infection of body cells by antigens -T-cell activation

infection of body cells by antigens

Suppressor T cells act to -limit antigen proliferation. -suppress antigens. -inhibit T and B cell activities. -produce antibodies involved in autoimmunity. -erase memory T cells.

inhibit T and B cell activities.

The effects of activating the complement system include all of the following except -histamine release. -stimulation of inflammation. -enhanced phagocytosis. -destruction of target cell plasma membranes. -inhibition of the immune response.

inhibition of the immune response

Immunity that is genetically determined and present at birth is called ________ immunity. -active -natural passive -passive -auto -innate

innate

Which of the following are secreted by T cells and NK cells, and stimulate macrophage activity? -interferon gamma -interferon beta -complement proteins -interferon alpha

interferon gamma

The process by which the surface of a microorganism is covered with antibodies and complement, rendering it more likely to be phagocytized, is called -opsonization. -agglutination. -antigen presentation. -neutralization. -sensitization.

opsonization

In an experimental situation, a rabbit is exposed to a viral antigen to which it makes antibodies. These antibodies are then purified and injected into a human with the same viral disease. This is an example of -active immunization. -passive immunity. -innate immunity. -natural immunity. -alloimmunity.

passive immunity

The first line of cellular defense against pathogens are the -B cells. -NK cells. -T cells. -phagocytes. -plasma cells.

phagocytes

In response to tissue damage and infection, circulating proteins called pyrogens -opsonize pathogens. -cause inflammation. -activate complement. -activate antibodies. -produce a fever.

produce a fever

Lymph nodes do all of the following except -produce antibodies. -detect pathogens. -remove excess nutrients from the lymph. -remove debris and pathogens from the lymph. -monitor the contents of lymph.

remove excess nutrients from the lymph.

Lymphocytes -are all actively phagocytic. -are primarily found in red bone marrow. -respond to antigens. -destroy red blood cells. -decrease in number during infection.

respond to antigens

B cells prepare for activation by presenting an antigen bound to Class II MHC proteins in a process called -customization. -differentiation. -sensitization. -apoptosis. -opsonization.

sensitization

Defense of the body against a particular pathogen is provided by -fever. -immunological surveillance. -nonspecific immunity. -specific immunity. -skin defenses.

specific immunity

Interferons are released by some macrophages and lymphocytes, but also by cells carrying what pathogen? -viruses -bacteria -prions -spirochetes -parasites

viruses

In general, lymphocytes -have one nucleus. -have relatively long life spans. -spend most of their time in lymphoid tissue. -All of the answers are correct. -None of the answers is correct.

All of the answers are correct

Inflammation produces localized -pain. -swelling. -redness. -heat. -All of the answers are correct.

All of the answers are correct

Lymphocyte production involves -bone marrow. -thymus tissue. -peripheral lymphoid tissues. -All of the answers are correct. -None of the answers is correct.

All of the answers are correct

The role of antigen-presenting cells in immunity is to -display antigen fragments. -process antigens. -activate T cells. -All of the answers are correct. -None of the answers is correct.

All of the answers are correct

Characteristics of specific defenses include -versatility. -tolerance. -specificity. -memory. -All of the answers are correct.

All of the answers are correct.

The cells responsible for antibody-mediated immunity are the ________ cells. -NK -helper T -cytotoxic T -B -suppressor T

B

When an antigen is bound to a Class II MHC protein, it can activate a(n) ________ cell. -NK -plasma -CD4 T -suppressor T -cytotoxic T

CD4 T

Class I MHC proteins are recognized by which of the following cell types (that are destined to become T cells)? -CD4 -CD8

CD8

________ cells provide cell-mediated immunity. -Cytotoxic T -Suppressor T -CD4 T -CD8 T -Memory B

CD8 T

Which major class of lymphocytes become cytotoxic T cells? -CD8 cells -CD6 cells -CD4 cells

CD8 cells

Lymphoid organs differ from lymphoid tissues in what way? -They contain T lymphocytes and lymphoid tissues do not. -They cannot produce antibodies, whereas lymphoid tissues can. -They are surrounded by a fibrous capsule and lymphoid tissues are not. -They are found in the digestive tract and lymphoid tissues are found in the thorax. -None of the answers is correct.

They are surrounded by a fibrous capsule and lymphoid tissues are not.

Antigen-presenting cells are differentiated from other body cells by the presence of Class II MHC proteins in their plasma membranes. Which of the following correctly describes a difference between Class I and Class II MHC? -Macrophages use Class II MHC to display antigens they have phagocytized. -Class I MHC activates more types of lymphocytes than Class II MHC. -Class I MHC is produced in the Golgi apparatus, while Class II MHC is produced in the rough endoplasmic reticulum. -Cells must be infected by a pathogen before they can display its antigens on Class II MHC.

Macrophages use Class II MHC to display antigens they have phagocytized.

________ cells enable the immune system to respond quickly and robustly if the same antigen is encountered a second time. -Suppressor -Plasma -Dendritic -IgM -Memory

Memory

The cells that perform immunological surveillance are the ________ cells. -suppressor T -helper T -NK -plasma -B

NK

The cells directly responsible for cell-mediated immunity are the ________ cells. -T -plasma -interferon -B -NK

T

Adaptive immunity is the result of the actions of -T and B cells. -mast cells. -antigen-antibody complexes. -interferons. -NK cells.

T and B cells.

What is perforin? -a protein produced by NK cells -a destructive enzyme secreted by sebaceous glands -a toxin expressed by some pathogens that is capable of damaging healthy cells -a type of antibody synthesized by B cells -a type of interferon

a protein produced by NK cells

Cytotoxic T cells attack target cells by doing what? -secreting a strong acid -secreting free radicals -secreting organic solvent -activating genes that trigger apoptosis -secreting mutant proteins

activating genes that trigger apoptosis

Which of the following types of cells display protein fragments produced by the cancer within them? -macrophages -B cells -dendritic cells -all nucleated cells

all nucleated cells

The classic pathway of complement activation begins when the complement protein binds to -the cell wall of bacteria. -an antibody attached to an antigen. -the plasma membrane of bacteria. -a cell surface antigen. -a plasma protein.

an antibody attached to an antigen.

Class II MHC proteins are found on which of the following cell types? -all nucleated cells -antigen-presenting cells

antigen-presenting cells

A substance that provokes an immune response is called a(n) -thymosin. -chemotoxin. -complement. -irritant. -antigen.

antigen.

The alternative pathway for complement action: -begins when several complement proteins, notably properdin, interact in the plasma. -is the most rapid and effective activation of the complement system. -ends with the conversion of an inactive complement protein to an activated form. -begins when one of the complement proteins attaches to antibody molecules already bound to their specific antigen.

begins when several complement proteins, notably properdin, interact in the plasma

Lymphatic vessels commonly occur in association with -blood vessels. -adipose tissue. -sensory nerve endings. -hyaline cartilage. -both hyaline cartilage and adipose tissue.

blood vessels

The attraction or repulsion of certain cells to chemicals in their environment is called -diapedesis. -phagocytosis. -apoptosis. -chemotaxis. -immune surveillance.

chemotaxis

Histamine increases blood flow and vascular permeability. This would account for all of the following changes that occur during inflammation except -chemotaxis of phagocytes. -heat of the inflamed tissue. -swelling of the inflamed tissue. -movement of defense proteins and cells into the interstitial space. -redness of the inflamed tissue.

chemotaxis of phagocytes

Which class of MHC proteins presents exogenous antigens? -class II MHC proteins -class I MHC proteins

class II MHC proteins

Each of the following is a physical barrier to infection except -complement. -secretions. -epithelium. -body hair. -basement membranes.

complement

Before specific defenses are activated, most antigens must -bind to the DNA of the lymphocyte. -depolarize the lymphocyte. -be processed by a phagocyte. -infect cells. -either infect cells or be processed by a phagocyte.

either infect cells or be processed by a phagocyte.

The lymphocytes are most important in -helping maintain normal blood volume. -transporting lipids from the digestive tract. -fighting infection. -eliminating variations in the composition of interstitial fluid. -transporting gases to and away from lymph nodes.

fighting infection

Complement: -is a specific defense. -involves the destruction of abnormal cells by NK cells in peripheral tissues. -is a system of circulating proteins that assists antibodies in the destruction of pathogens. -is a chemical messenger that coordinates the defenses against viral infections.

is a system of circulating proteins that assists antibodies in the destruction of pathogens

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

lymphocytes and antigen-presenting cells

An inflammatory response is triggered when -blood flow to an area increases. -red blood cells release pyrogens. -neutrophils phagocytize bacteria. -mast cells release histamine and heparin. -T cells release interferon.

mast cells release histamine and heparin

Various types of macrophages are derived from -lymphocytes. -monocytes. -neutrophils. -basophils. -eosinophils.

monocytes

Immunity that results from exposure to an antigen in the environment is called ________ immunity. -auto -natural acquired passive -innate -naturally acquired active -passive

naturally acquired active

Immunity that results from antibodies that pass the placenta from mother to fetus is called ________ immunity. -naturally acquired active -auto -passive -naturally acquired passive -innate

naturally acquired passive

Antigen presentation is __________. -the presence of antigens or antigenic fragments on plasma membranes -the presence of antigens in body fluids -only carried out by antigen-presenting cells (APCs) -not required for the activation of specific defenses

the presence of antigens or antigenic fragments on plasma membranes

Most of the lymph returns to the venous circulation by way of the -hepatic portal vein. -thoracic duct. -cisterna chyli. -dural sinus. -right lymphatic duct.

thoracic duct

Stem cells that will form T cells develop in the -liver. -thymus. -kidneys. -spleen. -bone marrow.

thymus

T is to ________ as B is to ________. -thyroid; bowel -top; bottom -non-thymus-dependent; bottom -thymus-dependent; bone marrow-derived -None of the answers is correct.

thymus-dependent; bone marrow-derived

Areas of the spleen that contain large aggregations of lymphocytes are known as -red pulp. -lymph nodes. -white pulp. -Peyer's patches. -adenoids.

white pulp