specific immunity

Question 1

what is specific immunity?

Answer 1

• target only one specific type of pathogen

- body’s third line of defense

Question 2

describe lymphocytes?

Answer 2

• B-cells + T-cells
• involved in both non-specific + specific
• produced in bone marrow
• roam through the body
• able to wander through tissue and then enter the blood or lymph to be transported to another part of the body where they enter another tissue

Question 3

describe b-cells

Answer 3

= produce antibodies that destroy pathogens

• Antibody-mediated immunity
• produced and matured in bone marrow
• works in body fluids

Question 4

describe T-cells

Answer 4

= produce chemicals that destroy cells interacting directly with their targets

• Cell-mediated immunity
• Produce killer cells
• produced in bone marrow
• matured in the thymus
• work on infected cells, cancerous cells, transplanted tissue

Question 5

what are antigens?

Answer 5

any substance capable of causing a specific immune response

- triggers both antibody-mediated and cell-mediated immunity

Question 6

what are self-antigens?

Answer 6

large molecules produced in a person’s own body that does not cause an immune response

Question 7

what are non-self antigens?

Answer 7

foreign compounds that do trigger an immune response

Question 8

what are antibodies?

Answer 8

a specialized protein produced by plasma cells in response to a non-self

Question 9

what is an antigen-antibody complex?

Answer 9

antibody produced in response to an antigen can combine with that antigen

Question 10

what are antigen-presenting cells?

Answer 10

specific cells which recognize and respond to a non-self antigen

Question 11

what cells are antigen-presenting cells?

Answer 11

• dendritic cells
• macrophages
• undifferentiated B-cells

Question 12

how do antigen-presenting cells present an antigen?

Answer 12

• detect the presence of non-self antigen
• engulf the pathogen
• digest pathogen, producing small fragments that move to the surface of the cell
• present the antigen to lymphocytes on the cell surface

Question 13

what are the 2 parts of the immune response?

Answer 13

antibody-mediated immunity

cell-mediated response

Question 14

what does antibody-mediated immunity do?

Answer 14

works against bacteria, toxins, and viruses before they enter the body’s cells

Question 15

describe the process of antibody-mediated immunity?

Answer 15

1) antigen-presenting cells recognize, engulf and digest pathogens, displaying the antigen on their surface
2) antigen-presenting cells reach lymphoid tissue and present the antigen to lymphocytes
3) helper T-cells are stimulated by antigen-presenting
4) specific B-lymphocytes are stimulated to undergo rapid cell division
5) most new B-cells develop into plasma cells, which produce antibodies and release them into blood and lymph
6) antibodies combine with specific antigen and inactivate or destroy it
7) some of the new B-cells form memory cells

Question 16

what does cell-mediated immunity do?

Answer 16

works against transplanted tissues and organs, cancer cells, and cells that have been infected by viruses or bacteria

Question 17

describe the process of cell-mediated immunity?

Answer 17

1) antigen-presenting cells reach lymphoid tissue and present the antigen to the lymphocyte
2) antigen-presenting cells reach lymphoid tissue and present the antigen to the lymphocyte
3) helper T-cells are stimulated by antigen-presenting cells, which release cytokines
4) specific T-cells are stimulated to undergo rapid cell division
5) most new T cells develop into killer T-cells or helper T-cells which migrate to the site of the infection
6) killer T-cells destroy the antigen, while helper T-cell’s promote phagocytosis by macrophages
7) some sensitized T-cells form memory cells

Question 18

describe what happens during the primary exposure to an antigen

Answer 18

= immune response resulting from first exposure to a specific antigen

• slow response
• memory cells to the specific antigens are produced

Question 19

why is the primary response fairly slow?

Answer 19

• takes time for B-cells to multiply and
  differentiate into plasma cells
  = takes time to build up large amounts
  of antibodies

Question 20

describe what happens during the secondary exposure to an antigen

Answer 20

= immune response resulting from second or subsequent exposure to a specific antigen

• faster
• antigen has little opportunity to exert any noticeable effect on the body – no symptoms, no illness result (the person is immune)

Question 21

why is the primary response much faster?

Answer 21

= due to memory cells
- Plasma cells formed quickly, in greater numbers, for longer periods of time, and in
high concentrations
- antibody levels in blood rise rapidly

Question 22

what are the two types of immunity?

Answer 22

passive

active

Question 23

what is immunity?

Answer 23

resistance to infection by invading pathogens

Question 24

how can immunity be gained?

Answer 24

natural = no medical intervention
artificial = with medical intervention

Question 25

describe passive immunity

Answer 25

- does not require exposure to antigen - person given antibodies produced by someone else - short lived immunity, lasting only until antibodies are brokem down + excreted - protection immediate but only temporary

Question 26

describe active immunity

Answer 26

- requires exposure to antigen - person makes their own antibodies - prolonged immunity, lasting for many years, often for life - protection slow to develop but permanent

Question 27

compare passive natural immunity and passive artificial immunity

Answer 27

natural - antibodies enter blood across placenta and in breast milk artificial - antibodies injected into the bloodstream - used in rapidly developing serious infections

Question 28

compare active natural immunity and active artificial immunity

Answer 28

natural - formation of memory cells resulting from attack of disease artifical - formation of memory cells resulting from given atigen by vaccination

Question 29

what are the 3 types of T cells that develop when T cells are not used as memory cells

Answer 29

1) killer T cells 2) helper T cells 3) suppressor T cells

Question 30

what are killer T cells?

Answer 30

- migrate to the site of infection and deal with invading antigen - attach to invading cells and secrete a chemical that will destroy the antigen and then go in search of more antigens

Question 31

what are helper T cells?

Answer 31

- humoral and cellular immunity | - bind to the antigen on antigen-presenting cells, stimulating the secretion of cytokines

Question 32

what are suppressor T cells?

Answer 32

- act when the immune activity becomes excessive or the infection has been dealt with successfully - release substances that inhibit T and B cell activity, slowing down the immune response

Question 33

how do antibodies work to protect the body?

Answer 33

- inactivate foreign enzymes by combining with them or inhibiting their reaction with other cells or compounds - bind to the surface of viruses and prevent them from entering cells - coat bacteria so that they are more easily consumed by phagocytes - agglutination = cause particles to clump together - dissolve organisms - react with soluble substances to make them insoluble and thus more easily consumed by phagocytes