Ch:24 Immune System

Question 1

Which WBCs are classified as

Granulocytes?

Answer 1

Mast cells, Basophils, Eosinophils & Neutrophils

Question 2

Which WBCs are classified as

Phagocytes?

Answer 2

Neutrophils, Macrophages & Monocytes

Question 3

Which WBCs are classified as

Cytotoxic cells?

Answer 3

Eosinophils, Lymphocytes & Plasma cells

Question 4

Which WBCs are classified as

Antigen-presenting cells?

Answer 4

Monocytes, Macrophages, Lymphocytes, Plasma cells & Dendritic cells

Question 5

Which WBCs are the most abundant in blood?

Answer 5

Neutrophils

Question 6

Which WBCs are the most rare?

Answer 6

Basophils and Mast cells

Question 7

Which WBCs are involved in inflammation & allergic response?

Answer 7

Basophils and Mast cells

Question 8

What are the differences between Innate immunity & acquired immunity?

Answer 8

Innate immunity recognizes pathogen-associated molecular patterns
& is mediated by phagocytes while acquired immunity recognizes specific antigens and is mediated by lymphocytes

Question 9

What 2 cells are B-lymphocytes?

Answer 9

Plasma cells & Memory cells

Question 10

What 2 cells are T-lymphocytes?

Answer 10

Cytotoxic T cells & Helper T cells

Question 11

What are the 6 functions of Antibodies?

Answer 11

1. Mark antigens for destruction
2. Enhance inflammation
3. antigen clumping
4. inactivation of bacterial toxins
5. Activate compliment & B lymphocytes
6. Trigger degranulation

Question 12

What are the 5 subclasses of antibodies?

Answer 12

IgG: activate complement (75% of plasma antibodies)

IgA: found in external secretions (saliva, tears, milk)

IgE: activate mast cells in allergic responses

IgM: activate compliment and involved in primary immune
response & blood group reactivity

IgD: surface of B-lymphocytes

Question 13

What to subclasses of antibodies activate complements (Fc end of antibody)?

Answer 13

IgG & IgM

Question 14

What happens in primary immune response?

Answer 14

exposure to an antigen triggers clonal expansion and the immune response

Question 15

What happens in secondary immune response?

Answer 15

when memory cells are reexposed to the appropriate antigen, the clone expands more rapidly to create additional effector and memory cells

Question 16

Is primary or secondary immune response faster and stronger?

Answer 16

secondary immune response

Question 17

What is the function of T lymphocytes and where do they mature?

Answer 17

to carry out cell mediated immunity by binding MHC- antigen complexes on target cells and they mature in the thymus gland

Question 18

What does the complement system do during a bacterial infection?

Answer 18

-complement proteins attract leukocytes
-cause degranulation of mast cells and basophils
-cytokines attract more immune cells
-histamine dilates blood vessels & increases permeability
-proteins & water enter extracellular fluid causing swelling
-membrane attack complex permeabilizes bacterial
membranes

Question 19

What type of cells are MHC Class l and how do they function?

Answer 19

all nucleated cells

mark cells for destruction by cytotoxic T cells

Question 20

What types of cells are MHC Class ll and what is their function?

Answer 20

macrophages, B lymphocytes & dendritic cells

stimulate helper T cells to secrete cytokines to enhance immune response

Question 21

What are the 2 subclass cells of T lymphocytes and what are their functions?

Answer 21

Cytotoxic T cells- release perforin & proteases to induce
apoptosis of target cells.

Helper T cells- release interferon Y to activate
macrophages
- release interleukins to activate antibody
production & stimulate cytotoxic T
lymphocytes, mast cells & eosinophils
-release colony stimulating factors to
enhance leukocyte production

Question 22

What do cytotoxic T cells bind to opposed to helper T cells?

Answer 22

cytotoxic T cells = MHC class l

Helper T cells = MHC class ll

Question 23

What are the steps involved in immune response to a bacterial infection?

Answer 23

1. Bacteria activates complement proteins
2. Opsonins coat bacterial cells with antigens &
   phagocytes engulf the uncoated bacteria
3. bacteria coated with antigen binds to T_H cells
4. T_H cells activate B lymphocytes to become plasma cells
5. Plasma cells secrete antibodies

Question 24

How does the immune system respond to a bacterial infection?

Answer 24

• memory cells are attracted to the area & initiate 2ndary immune response
• antigen-presenting cells activate hellper T cells
• Naive B cells are stimulated to produce plasma cells & memory cells (primary immune response)

Question 25

What are the steps involved in a viral infection?

Answer 25

1. Macrophages ingest virus 2. MHC ll on macrophage presents the virus antigen 3. macrophage secretes cytokines to induce inflammation and attract Helper T cells to bind to macrophage 4. once bound, T_H cells activate B lymphocytes to become plasma cells that secrete antibodies 5. T_H cell activate cytotoxic T cells at T-receptor and release perforin & granzymes that induce apoptosis

Question 26

How are viruses prevented from entering cells in the body?

Answer 26

Opsonins mark virus for macrophages to ingest

Question 27

What do macrophages release to prevent the virus from replicating?

Answer 27

a-interferons

Question 28

How do cytotoxic T cells recognize infected cells and what do they release to promote apoptosis

Answer 28

MHC class l (different than macrophages MHC ll) release perforin and granzymes to induce apoptosis

Question 29

What is it called when during the primary immune response, naive B lymphocytes divide to form plasma and memory cells?

Answer 29

Clonal expansion

Question 30

What occurs in the primary immune response?

Answer 30

clonal expansion (naive B lymphocytes divide to form plasma and memory cells)

Question 31

What occurs in the secondary immune response?

Answer 31

memory cells reproduce for a rapid response

Question 32

Where do all nucleated cells display the foreign antigen?

Answer 32

MHC l

Question 33

What cells is humoral immunity involved in and what is it mediated by?

Answer 33

B lymphocytes and mediated by antibody secretion

Question 34

What cells is cell-mediated immunity involved in and what is it mediated by?

Answer 34

T lymphocytes and mediated by T cell receptors binding to MHC-antigen complexes?

Question 35

What is the summary of the immune response in a bacterial infection?

Answer 35

activation of complement, phagocytosis of bacteria, primary & secondary response

Question 36

What is the summary of the immune response regarding a viral infection?

Answer 36

primary and secondary immune response against free virus, ingestion of virus by macrophage, activation of cytotoxic T cells to kill infected cells

Question 37

How do histamines cause inflammation?

Answer 37

dilating blood vessels & increasing permeability

Question 38

What is the role of helper T cells?

Answer 38

stimulate antibody production by B cells

Question 39

What 2 cells do helper T cells activate and what does the activated cell become?

Answer 39

B lymphocytes to become plasma cells & cytotoxic T cells to release perforin & granzymes

Question 40

What do cytotoxic T cells secrete and what do the secretions cause?

Answer 40

perforin & granzymes for apoptosis

Question 41

What are the 6 steps in an allergic response?

Answer 41

1. allergen ingested & processed by antigen-presenting cell 2. antigen-presenting cell activates Helper T cell 3. Helper T cell activates B lymphocyte 4. B lymphocyte becomes plasma & memory cells 5. Memory B and T cells retain memory of exposer to allergen 6. upon reexposer to allergen, B & T cells activate more quickly. The body reacts strongly by releasing histamines, cytokines, and other mediators causing allergic symptoms

Question 42

What type of antigens and antibodies are present on type O blood?

Answer 42

Antigen: NONE Antibody: A & B

Question 43

What type of antigens and antibodies are present on type A blood?

Answer 43

Antigen: A Antibody: B

Question 44

What type of antigens and antibodies are present on type B blood?

Answer 44

Antigen: B Antibody: A

Question 45

What type of antigens and antibodies are present on type AB blood?

Answer 45

Antigen: A & B Antibody: NONE

Question 46

What does a massive release of histamine cause in an allergic rxn?

Answer 46

systemic vasodilation, bronchoconstriction, and collapse of the circulatory system

Question 47

What happens during reexposer during an allergic response?

Answer 47

allergen binds to IgE on Mast cells releasing histamine and cytokines

Question 48

What happens during sensitization during an allergic response?

Answer 48

1. allergen is ingested by macrophage 2. helper T cells are activated 3. helper T cells activate B cells to become plasma cells making IgE & IgG 4. IgE binds to Mast cells and basophils

Question 49

How are foreign organs rejected by the body?

Answer 49

foreign MHC proteins activate cytotoxic T cells & helper T cells which kills foreign tissue

Question 50

How are autoimmune diseases caused?

Answer 50

T lymphocytes recognizing self HLA are eliminated by the thymus---> failure of this system results in autoimmune disease