Immunology

Question 1

external defenses

Answer 1

skin, mucous membrane, and enzyme secetions

Question 2

internal defenses

Answer 2

phagocytes, antimicrobial proteins, inflammation, and natural killer cells

Question 3

neutrophil

Answer 3

phagocyte; 60-70% of leukocytes; life span few days; home to infected tissue

Question 4

macrophage

Answer 4

develop from monocytes; some reside in specific lymphatic tissue

Question 5

eosinophil

Answer 5

low phagocyte activity; defense against multicellular parasites with enzymes

Question 6

dendritic cell

Answer 6

phagocytic, but primary role is stimulating acquired immunity

Question 7

interferon alpha + beta

Answer 7

provide innate defense against viral infections

Question 8

complement system

Answer 8

30 serum proteins that are antimicrobial proteins

Question 9

mast cells

Answer 9

releases histamine, which triggers dilation and increased permeability of nearby capillaries

Question 10

chemokine

Answer 10

small proteins of cytokine family that attract phagocytic cells

Question 11

natural killer cells

Answer 11

innate defense; attack virus infected cells and cancer cells causing apoptosis

Question 12

hemocytes

Answer 12

insect white blood cells found in hemolymph

Question 13

cytokines

Answer 13

phagocytes secrete these proteins that help activate lymphocytes

Question 14

lymphocytes

Answer 14

B or T cells with about 100,000 identical antigen receptors on the surface

Question 15

Immunoglobulins

Answer 15

structurally similar to B cell receptors, but lack a transmembrane domain

Question 16

B cell receptors

Answer 16

noncovalent bonds with intact antigens

Question 17

T cell receptors

Answer 17

one a and b chain; recognizes small fragments of antigens that are bound to MHC molecules

Question 18

class I mhc

Answer 18

found on almost all nucleated cells; antigen display is recognized by cytotoxic T cells

Question 19

class II mhc

Answer 19

made on antigen presenting cells dendritic cells, macrophages, and b cells; display is recognized by helper T cells

Question 20

thymus

Answer 20

lymphocytes that migrate from bone marrow to here develop into T cells

Question 21

lymphocyte activation

Answer 21

binding of antigen activates lymphocyte and stimulates division into clones

Question 22

humoral immune response

Answer 22

plasma and memory b cells; secretion of antibodies

Question 23

cell mediated immune response

Answer 23

activation and clonal selection of cytotoxic t cells

Question 24

CD4

Answer 24

present on helper T cells; binds to the class II MHC molecule

Question 25

dendritic cell-T cell

Answer 25

effective in presenting antigens to naive helper T cells

Question 26

macrophage - T cell

Answer 26

initiate a secondary immune response by presenting antigens to memory helper T cells

Question 27

B cell - T cell

Answer 27

primarily present antigens to helper T cells during humoral response

Question 28

CD8

Answer 28

present on cytotoxic T cells; binds to the class I MHC molecule

Question 29

helper T cell activation

Answer 29

binds to antigen-MHC II complex with TCR and secretes cytokines for B cells and cytotoxic T cells; produces helper T clones

Question 30

cytotoxic T cell activation

Answer 30

with the help of MHC I and cytokines perforin and granzymes are released causing apoptosis

Question 31

plasma B cells

Answer 31

after activation these effector cells secrete antibodies to the antigens that this B cell is specific for

Question 32

B cell internalization

Answer 32

dendritic cell internalizes peptide fragments from variety of antigens; presents only antigen to which it specifically binds

Question 33

T dependent antigen

Answer 33

induce antibody production only with assistance from helper T cells

Question 34

T independent antigens

Answer 34

weaker response with bacteria capsules and flagella; does not generate memory B cells

Question 35

memory B cells

Answer 35

activated effector B cells with antibodies on the membrane

Question 36

polyclonal antibody

Answer 36

products of many different clones of B cells, each specific for a different epitope

Question 37

monoclonal antibody

Answer 37

identical and specific for the same epitope on an antigen

Question 38

viral neutralization

Answer 38

antibodies bind to surface of virus and blocks host binding as well as enhancing phagocytosis

Question 39

opsonization

Answer 39

binds to pathogenic bacterium and enhances macrophage phagocytosis

Question 40

antigen precipitation

Answer 40

antibodies cross link soluble antigen molecules and aggregates

Question 41

agglutination

Answer 41

clumps bacteria or virus for phagocytosis; commonly performed by IgM

Question 42

antibody-complement proteins

Answer 42

complement proteins bind to antigen-antibody complex and causes cell lysis

Question 43

IgM

Answer 43

pentamer; first Ig class produced after initial antigen exposure; agglutination

Question 44

IgG

Answer 44

confers passive immunity on fetus; most abundant Ig in blood

Question 45

IgA

Answer 45

dimer; present in secretions; confers passive immunity in milk; mucous membrane defense

Question 46

IgE

Answer 46

triggers release of histamine from mast cells and basophils that cause allergic reaction

Question 47

IgD

Answer 47

present on surface of naive B cells; antigen receptors in antigen stimulated proliferation of B cells