Exam 2 (Ch. 21)

Question 1

first line of defense

Answer 1

external body membranes (skin & mucosa)

Question 2

second line of defense

Answer 2

antimicrobial proteins, phagocytes and other cells
-phagocytes, NK cells, inflammatory response, antimicrobial proteins & fever

Question 3

third line of defense

Answer 3

B and T cells; attacks specific foreign substances

Question 4

what are the 3 stages of an inflammatory response

Answer 4

stage 1: inflammatory and chemical release
stage 2: vasodilation and increase vascular permeability
stage 3: phagocyte mobilization

Question 5

what occurs during stage 1 of the immune response

Answer 5

chemicals are released into ECF by injured tissues or immune cells

Question 6

what occurs during stage 2 of the immune response

Answer 6

-vasodilation causes hyperemia (congestion with blood) that leads to redness and heat
-increased capillary permeability causes exudate (fluid containing clotting factors and antibodies) to leak into tissues and cause swelling

Question 7

what occurs during stage 3 of the immune response

Answer 7

neutrophils flood the area first, followed by macrophages

Question 8

four cardinal signs of inflammation

Answer 8

(1) redness
(2) heat
(3) swelling
(4) pain

Question 9

what are the benefits of inflammation

Answer 9

-prevents the spread of damaging agents to nearby tissues
-disposes of cell debris & pathogens
-alerts the adaptive immune system
-sets the stage for repair

Question 10

Molecules that make up the complement system and where would you find these molecules

Answer 10

consists of 20 blood proteins that circulate in blood in their inactive form
-includes proteins C1-C9, regulatory proteins and factors B, D & P

Question 11

Different pathways that activate the complement system

Answer 11

(1) classical pathway
(2) lectin pathway
(3) alternative pathway

Question 12

three different outcomes once the complement system is activated

Answer 12

(1) enhances inflammation
(2) promotes phagocytosis
(3) causes cell lysis

Question 13

Characteristics of adaptive immunity

Answer 13

specificity- recognizes and targets specific antigens
systemic- not restricted to the initial state
memory- mounts an even stronger attack to known antigens upon repeated exposure

Question 14

which lymphocyte activates humoral immunity

Answer 14

B cells

Question 15

which lymphocyte activates cellular immunity

Answer 15

T cells

Question 16

what occurs during humoral immunity

Answer 16

antibodies produced by B lymphocytes circulate freely in body fluids and temporarily bind & inactivate an extracellular target, marks them for destruction

Question 17

what occurs during cellular immunity

Answer 17

T cells directly (kill infected cells) or indirectly (release chemicals to enhance inflammation or activate lymphocytes/macrophages) kill cancer cells or cells infected by a microbe

Question 18

2 major population of T cells

Answer 18

(1) CD4 cells (helper/regulatory)
(2) CD8 cells (cytotoxic)

Question 19

Cell surface markers that define each T cell population

Answer 19

CD4 glycoproteins- helper and regulatory T cells
CD8 glycoproteins- cytotoxic T cells

Question 20

which T cells activate B cells or other T cells and macrophages; direct the adaptive immune response

Answer 20

Helper T cells

Question 21

which T cells destroy cells with foreign antigens

Answer 21

Cytotoxic T cells

Question 22

which T cells respond to class I MHC proteins

Answer 22

CD8

Question 23

which T cells respond to class II MHC proteins

Answer 23

CD4

Question 24

which T cells slows or stops activity of the immune system by secreting inhibitory cytokines and transforming factor growth beta

Answer 24

regulatory T cells

Question 25

which T cells control autoimmune diseases; suppress self-reactive lymphocytes

Answer 25

regulatory T cells

Question 26

helper t cell that mediates most aspects of cell immunity

Answer 26

TH1

Question 27

helper t cell that defends against parasitic worms, mobilizes eosinophils, activates responses dependent on humoral immunity and promotes allergies

Answer 27

TH2

Question 28

helper t cell that links adaptive and innate immunity by releasing IL-17

Answer 28

TH17

Question 29

substances that can mobilize adaptive defenses and provoke an immune response

Answer 29

antigens

Question 30

what are antigens

Answer 30

mostly large, complex molecules not normally found in the body (foreign intruders/ non-self)

Question 31

two important functions of complete antigens

Answer 31

(1) immunogenicity - the ability to stimulate specific lymphocytes to proliferate (2) reactivity - the ability to react with the activated lymphocytes and the antibodies released by immunogenic reactions

Question 32

antigenic determinants

Answer 32

parts of the antigen that antibodies or lymphocyte receptors bind to

Question 33

what are the two processes associated with lymphocyte education

Answer 33

(1)positive selection - selects T cells capable of recognizing self MHC proteins (2) negative selection- t cells that bind to self-antigens displayed by self MHC undergo apoptosis

Question 34

what is the purpose of positive and negative selection

Answer 34

immunocompetence and self-tolerance

Question 35

proteins released from virus infected cells & certain lymphocytes that acts as chemical messengers to protect uninfected cells from viral infection and mobilize the immune system

Answer 35

interferons

Question 36

IFN- alpha and IFN-beta

Answer 36

enter neighboring cells to stimulate production of proteins that block viral production and degrade viral RNA; activate NK cells

Question 37

IFN-gamma

Answer 37

secreted by lymphocytes and activates macrophages

Question 38

cell proliferation after the first exposure to an antigen

Answer 38

primary immune response

Question 39

re-exposure to the same antigen that gives faster, more prolonged and more effective response

Answer 39

secondary immune response

Question 40

which immune response; -has a lag period of 3-6 days for antibody production to begin -peak levels of plasma antibody are reached in 10 days -antibody levels then decline

Answer 40

primary

Question 41

which immune response; -has sensitized memory cells -antibody production is immediate with peak levels in 2-3 days at much higher levels and with greater affinity -high antibody levels for weeks to months

Answer 41

secondary

Question 42

humoral immunity that occurs when B cells naturally encounter antigens and produce specific antibodies against them

Answer 42

Active humoral immunity

Question 43

humoral immunity that occurs when ready made antibodies are introduced into the body, B cells are not activated by the antigen and immunological memory does not occur

Answer 43

passive humoral response

Question 44

how do humans acquire naturally acquired active immunity

Answer 44

formed in response to bacterial or viral infection

Question 45

how do humans acquire artificially acquired active immunity

Answer 45

vaccines

Question 46

how do humans acquire naturally acquired passive immunity

Answer 46

antibodies delivered to fetus via placenta, or to infant via milk

Question 47

how do humans acquire artificially acquired passive immunity

Answer 47

injection of serum such as gamma globulin

Question 48

what are the two benefits of vaccines

Answer 48

(1) weakend antigens provide functional antigenic determinants that are both immunogenic and reactive (2) spare us from symptoms

Question 49

what is in a vaccine

Answer 49

pathogens that are dead or attenuated or their components; mRNA that codes for a viral protein

Question 50

how are antibodies produced

Answer 50

secreted in response to an antigen by plasma cells

Question 51

4 mechanisms of antibody action

Answer 51

(1) Neutralization (2) agglutination (3) precipitation (4) component fixation