Ch 43 pt 2

Question 1

Describe activation of B cells (6)

Answer 1

1) Helper T cells activated by macrophage antigen-presenting cells (via cytokines)
2) antigen binds to receptors on surface of b cell
3) B cell takes some antigens in by receptor-mediated endocytosis
4) Class II MCH protein of B cell presents antigen to helper T cells
5) activated helper T cells recognize the antigen and release cytokines that activate B cells
6) activated B cells divide to produce plasma cells and memory B cells

Question 2

Every ________ has multiple _______

Answer 2

antibody; epitopes

Question 3

How do antibodies deal with pathogens?

Answer 3

they mark pathogens for inactivation or destruction, they don’t kill them

Question 4

explain the antibody function of neutralization (2)

Answer 4

1) Antibodies bind to viral surface proteins which prevent infection of a host cell
2) Antibodies can also bind to toxins preventing them from entering body cells

Question 5

explain the antibody function of opsonization (2)

Answer 5

1) antibodies bind to antigens on bacteria, which leads to phagocytosis
2) enhances antigen presentation and humoral immunity (positive feedback)

Question 6

Explain antigen-antibody complexes (2)

Answer 6

1) The complex binds to complement proteins which triggers activation cascade of complement proteins
2) ultimately forms a membrane attack complex

Question 7

Explain the antibody function of agglutination (3)

Answer 7

1) Antibodies bind to antigen
2) 2 binding sites allow clumping of multiple antigens
3) phagocytosis

Question 8

explain the antibody function of precipitation (3)

Answer 8

1) Antibodies bind to DISSOLVED antigen
2) 2 binding sites allow clumping of multiple
3) phagocytosis

Question 9

What are the 5 different types of Ig in B cells?

Answer 9

1) IgD (membrane bound)
2) IgA
3) IgE
4) IgG
5) IgM
2-5 soluble

Question 10

Explain cytotoxic T cell activation (8)

Answer 10

1) infected cell picks up part of virus
2) antigen presented on class I MHC in an endosome via exocytosis
3) CD8 on cytotoxic T cell helps it recognize the class I MHC
4) cytokines from helper T cell confirms foreign
5) Interleukin 2 from helper T cell activates cytotoxic T cell stimulating proliferation
6) army of specialized helper T cells and cytotoxic T cells go out and eliminate threats
7) vesicles contain perforins that create channels in infected cell allowing water to rush in
8) infected cell bursts (lysis)

Question 11

What is the basis for immunization?

Answer 11

projection by the second immune response

Question 12

What is immunization carried out by?

Answer 12

vaccines

Question 13

What are the 2 types of immunity in immunization?

Answer 13

1) active immunity
2) passive immunity

Question 14

When does active immunity develop?

Answer 14

it develops naturally when a pathogen invades

Question 15

What are 2 examples of passive immunity?

Answer 15

1) IgG from mother to fetus via placenta
2) IgA from mother to infant via breast milk

Question 16

What is artificial passive immunity?

Answer 16

antibodies from immune animal injected into nonimmune animal

Question 17

What are monoclonal antibodies?

Answer 17

Antibodies prepared from a single clone grown in culture
- These antibodies are specific for one epitope

Question 18

Explain the complications of immune rejection

Answer 18

complicates blood transfusions and tissue/organ transplants

Question 19

What are the 2 ways to work around immune rejection in transplants?

Answer 19

1) surgeons use donor with similar MHC molecules to the patient to minimize rejection
2) patients take medicine to reduce immune response

Question 20

What are the 4 blood groups?

Answer 20

A: A-antigen
B: B-antigen
AB: both antigens
O: neither antigens

Question 21

What are allergies?

Answer 21

Allergies are exagerated (hypersensitive) responses to antigens called allergens

Question 22

Explain allergies (6)

Answer 22

1) IgE antibodies produced to an allergen attach to receptors on mast cells
2) the next time allergen enters the body it’ll bind to mast-cell-associated IgE molecules
3) Mast cells release histamine and other inflammatory chemicals
4) allergy symptoms stimulated
5) acute allergic reaction may lead to anaphylactic shock
6) injection of epinephrine can counteract allergic response

Question 23

What happens when one gets an autoimmune disease?

Answer 23

Immune system loses self tolerance

Question 24

What are the 4 types of autoimmune diseases?

Answer 24

1) lupus erythematosus
2) rheumatoid arthritis
3) insulin dependent diabetes milletus
4) multiple sclerosis

Question 25

What are the 3 physicals that affect the immune system?

Answer 25

1) exercise
2) physiological stress
3) sufficient rest

Question 26

What are the 2 ways antigens variate?

Answer 26

1) change epitope expression
ex) human infuenza virus
2) Human viruses may exchange genes with virus of domestic animals
ex) corona virus

Question 27

What is latency?

Answer 27

When a virus remains in host in inactive state
ex) herpes simplex virus

Question 28

What is HIV?

Answer 28

Human Immunodeficiency virus
1) infects T cells
2) able to persist in host because of mutations
3) able to abolish adaptive immune response
4) leads to acquired immunodeficiency syndrome (AIDS)

Question 29

What does AIDS do?

Answer 29

Makes people highly susceptible to infections and cancer

Question 30

What are the characteristics of cancer?

Answer 30

Frequency increases when adaptive immunity is inactivated
Immune system can defend against viruses that cause cancer and cancer cells that have viruses

Question 31

Which virus has a vaccine?

Answer 31

HPV (papillomavirus); causes cervical cancer