Immune System

Question 1

Antigen:

Answer 1

substance foreign to the host that can stimulate the immune response (aka immunogens)

Question 2

Epitope:

Answer 2

• Discrete, immunologically active sites on antigens.
• Interacts with the antibody
• Each one can activate a distinct clone of T/B cells

Question 3

Major Histocompatibility Complex (MHC) molecules:

Answer 3

self recognition molecules located on the surface of ALL nucleated cells

Question 4

Class I MHC molecules:

Answer 4

found on ALL nucleated cells

Question 5

Class II MHC molecules:

Answer 5

found only on macrophages and B-lymphocytes

Question 6

Cytokines:

Answer 6

small proteins produced during an immune response that regulate leukocytes

Question 7

What creates cytokines?

Answer 7

Helper T cells, macrophages, and fibroblasts

Question 8

Examples of cytokines:

Answer 8

• interleukins
• interferons
• TNF
• colony stimulating factor

Question 9

What is the first line of defense for Non-specific defense mechanisms?

Answer 9

• skin

- mucus membranes

Question 10

What is the second line of defense for Non-specific defense mechanisms?

Answer 10

• portion of inflammatory response initiated by tissue injury
  
  • vasodilation
  • capillary leakiness
  • chemotaxis
  • phagocytosis
  • opsonins
  • activation of compliment

Question 11

What are opsonins?

Answer 11

antibodies that can bind to bacteria and enhance phagocytic activity

Question 12

What 3 things does compliment do?

Answer 12

1. ) Membrane attack complex (poke holes in cell to kill)
2. ) Enhances inflammatory response
3. ) Act as opsonizing agent

Question 13

When is compliment more likely to be activated? (keep in mind it is always in blood in inactive form)

Answer 13

When bacteria is present!

Question 14

What are the other 2 non-specific mechanisms?

Answer 14

1. ) IFN-a and IFN-B release by leukocytes and fibroblasts

2. ) NK that kills non-specifically

Question 15

What happens when NK has a component of the specific immune response?

Answer 15

It can proliferate to significant numbers

Question 16

Specific immune defense mechanism is “specific” because it:

Answer 16

requires the recognition of a specific antigen

Question 17

What are the two types of Specific immune response?

Answer 17

1. ) Antibody-mediated (humoral) immunity

2. ) Cell-mediated immunity

Question 18

What is antibody-mediated immunity in response to?

Answer 18

bacteria and extracellular viruses

Question 19

What is cell-mediated immunity in response to?

Answer 19

cancer cells and intracellular viruses (self cells gone bad)

Question 20

Which is faster: specific or non-specific immunity?

Answer 20

non-specific (inflammation)

Question 21

Where are the two places that antibodies can be found?

Answer 21

1. ) the surface of B lymphocytes (as receptors)

2. ) as soluble antibodies produced by plasma cells

Question 22

Where can IgA antibodies be found?

Answer 22

breast milk and other secretions

Question 23

Where can IgD antibodies be found?

Answer 23

surface of immature B lymphocytes (maybe needed for maturation?)

Question 24

What do IgE antibodies do?

Answer 24

• rarest one! (0.004%)
• triggers most powerful immune reactions
• binds to mast cells and basophils
• allergic reactions!

Question 25

What do IgG antibodies do?

Answer 25

• most abundant! (75%)
• can cross placenta to help developing fetus
• binds to macrophages and activates compliment

Question 26

What do IgM antibodies do?

Answer 26

• against A/B RBC antigens

- very large, doesn’t diffuse easily