Unit 3 Immune

Question 1

immunity

Answer 1

ability of an organism to respond to and repel invasion by forming substances

Question 2

innate (nonspecific) immunity

Answer 2

physical barriers

secretions with antimicrobial activity

Question 3

acquired (adaptive, specific) immunity

Answer 3

specific, directed toward specific agent

Question 4

cells required for acquired immunity

Answer 4

1. presenters of foreign substance to responders
2. responders that produce antibodies
3. responders that destroy infected cells

Question 5

innate surface barriers

Answer 5

skin

mucous membranes

Question 6

innate internal defenses

Answer 6

phagocytes
fever
NK cells
antimicrobial proteins
inflammation

Question 7

humoral immunity

Answer 7

adaptive

B cells

Question 8

cellular immunity

Answer 8

adaptive

T cells

Question 9

antigens

Answer 9

a. substances that can mobilize immune response
b. may be soluble or attached to cell
c. may be proteins, polysaccharides, or lipids
d. contain epitopes
e. can be self-antigen

Question 10

types of antigens

Answer 10

complete

hapten (incomplete, must be bound to body’s self protein)

Question 11

epitope

Answer 11

antigenic determinants

specific portion of antigen recognized

Question 12

antibody characteristics

Answer 12

a. produced by plasma cells
b. glycoproteins of immunoglobulin family
c. soluble or attached to surface of lymphocytes
d. recognized bind to specific epitope

Question 13

antibody structure

Answer 13

1. multimeric protein (2 light/heavy proteins)
2. Fc region
3. Fab region

Question 14

Fab region

Answer 14

a. antigen binding
b. hypervariable
c. two per molecule

Question 15

IgM

Answer 15

1. first antibody produced in initial immune response
2. bound to B lymphocytes
3. stimulates clonal expansion and differentiation of plasma cells

Question 16

IgG

Answer 16

1. most abundant antibody in blood
2. produce in late primary and secondary response
3. facilitates destruction of bacteria and viruses

Question 17

IgE

Answer 17

1. Fc region binds to receptors on mast cells and basophils
2. low levels in blood
3. antibody-mast cell complex stimulates release of histamine and other molecules

Question 18

IgA

Answer 18

1. in secretions (saliva, tears, etc.)
2. enzyme resistant
3. active against bacteria and viruses

Question 19

IgD

Answer 19

very low concentration, mostly bound to B lymphocytes

Question 20

lymphocyte characteristics

Answer 20

1. multiple subpopulations

2. distinguished by membrane proteins; cluster differentiation markers, receptors

Question 21

T lymphocytes

Answer 21

a. T cell receptor (TCR) on cell surface
b. only recognize epitopes bound to receptors (MHC) molecules on other cells
c. subpopulations distinguished by CD markers

Question 22

CD 4

Answer 22

helper T cells; central to immune response; coordinate response of other lymphocytes

Question 23

CD 8

Answer 23

cytotoxic T cells

T supressor cells

Question 24

cytotoxic T cells

Answer 24

involved in cell-mediated response

Question 25

T supressor cells

Answer 25

turn off response

Question 26

B lymphocytes

Answer 26

1. IgM bound to surface with Fab fragment exposed 2. recognized epitope becomes activated 3. clonal expansion 4. differentiate into plasma cells and memory B cells 5. anamnestic response

Question 27

clonal expansion

Answer 27

proliferation of activated B cells

Question 28

anamnestic response

Answer 28

powerful response to second exposure

Question 29

MHC characteristics

Answer 29

a. integral membrane proteins b. combine with peptides derived from viruses or other foreign substances c. display forming antigens on cell surface

Question 30

MHCI

Answer 30

a. found on cell surfaces | b. present antigent to cytotoxic T cells

Question 31

MHCII

Answer 31

1. found on antigen presenting cells – macrophages, dendritic cells, activated T cell, etc. 2. presentation to helper T cell is central to coordinating immune response

Question 32

antigen presenting cells (APC)

Answer 32

macrophage | T helper cell (CD4)

Question 33

macrophage

Answer 33

1. ingestion and partial digestion of foreign substance | 2. presentation of foreign material on surface by MCHII

Question 34

T helper cell (CD4)

Answer 34

1. recognizes MHCII-antigen complex 2. binds to macrophage 3. activates cytotoxic T cells 4. activates B cells to create plasma cells generating antibodies

Question 35

primary response

Answer 35

1. takes 
about two weeks to develop peak 
antibody levels and activities 
(titers). 2. IgM and IgG antibody
concentrations do not remain
elevated.

Question 36

secondary response

Answer 36

1. characterized by a very rapid increase
in IgG antibody concentration and titer, 
rises to levels much higher than those
of the primary response. 2. Antibody 
activity remains elevated for an
extended period after the second
exposure to the antigen.

Question 37

roles of helper T cells

Answer 37

1. Activate both humoral and cellular arms 2. Once primed by APC presentation of antigen, helper T cells: a. Help activate B cells and other T cells b. Induce T and B cell proliferation c. Secrete cytokines that recruit other immune cells 3 Without TH, there is no immune response

Question 38

phagocytic cells

Answer 38

neutrophils macrophages Langerhan’s cells dendritic cells

Question 39

removal of bacteria

Answer 39

by neutrophils: margination diapedesis

Question 40

margination

Answer 40

attraction of circulating neutrophils: a. endothelial cells secrete attractant molecules b. neutrophils slow and briefly adhere to endothelium

Question 41

diapedesis

Answer 41

movement of neutrophils between endothelial cells into connective tissue