Immunity

Question 0

What is the role of transferrin and lactoferrin, and where can they be found?

Answer 0

Sequesters iron; found in saliva, mucus, milk, blood, and extracellular fluid

Question 1

What is the role of lysozyme, and where can it be found?

Answer 1

Degrades peptidoglycan; found in tears, saliva, mucus, phagocytic cells, blood, extracellular fluid

Question 2

What is the role of anti-microbial peptides (AMPs)?

Answer 2

Disrupt integrity of bacterial cells by forming pores; found in mucous membranes and within phagocytic cells

Question 3

Define: pathogenicity

Answer 3

The ability of an organism to cause disease

Question 4

Define: virulence

Answer 4

How pathogenic an organism is

Question 5

How are invaders detected by the immune system?

Answer 5

Toll-like receptors (TLRs) bind to pathogen-associated molecular patterns (PAMPs)

Question 6

What are a few types of PAMPs?

Answer 6

Flagellin, peptidoglycan, LPS, dsRNA, unmethylated DNA

Question 7

Which immune cells are phagocytes?

Answer 7

Macrophages, mast cells, neutrophils, and dendritic cells

Question 8

Which of the phagocytes can kill bacteria extracellularly, and how do they do this?

Answer 8

Neutrophils; they release web-like genetic material

Question 9

What is the role of antigen-presenting cells?

Answer 9

They display digested microbial antigens on their surface and activate T-helper cells

Question 10

In the complement system, what is the role of C3b?

Answer 10

It activates C5, splitting it into C5a and C5b. It also binds to foreign material (opsonization) to make phagocytosis easier.

Question 11

What is the role of C5a?

Answer 11

It acts as a powerful phagocyte chemoattractant. Together with C3a it also increases vascular permeability

Question 12

What is the role of C5b?

Answer 12

Togther with C6, C7, C8, and C9 it forms transmembrane channels in invaders (Membrane-attack complex MAC).

Question 13

How are natural killer cells inhibited?

Answer 13

Killer Inhibitor Receptors recognic class I MHC molecules on a cell surface

Question 14

What type of molecules are highly antigenic?

Answer 14

Proteins and polysaccharides

Question 15

What type of molecules are poorly antigenic?

Answer 15

Lipids and nucleic acids

Question 16

Which Ig is produced first during the primary response?

Answer 16

IgM

Question 17

Which Ig circulates as a pentamer?

Answer 17

IgM

Question 18

Which Ig is most abundant in blood and tissue fluids?

Answer 18

IgG

Question 19

Which Ig provides the longest-term protection?

Answer 19

IgG

Question 20

Which Ig is primary during the secondary response?

Answer 20

IgG

Question 21

Which Ig is most abundantly produced?

Answer 21

IgA

Question 22

Which Ig serves as B cell receptor?

Answer 22

IgD

Question 23

Which Ig is active against helminths and other parasites?

Answer 23

IgE

Question 24

Where do B-lymphocytes mature?

Answer 24

In the bone marrow

Question 25

Where do naive B-lymphocytes reside?

Answer 25

Lymphoid organs and tissues

Question 26

What three gene segments are joined together during B cell maturation?

Answer 26

V, D, and J

Question 27

What two events must occur in order for a B cell to activate?

Answer 27

An antigen must bind a B-cell receptor, and helper T cells must confirm

Question 28

Where do memory B cells reside?

Answer 28

Bone marrow, lymph nodes, spleen

Question 29

What do helper T cells do, once activated?

Answer 29

Release cytokines and help activate B cells, macrophages, and cytotoxic T cells

Question 30

What is Type I hypersensitivity?

Answer 30

Anaphylactic--IgE triggers release of cytokines by mast cells

Question 31

What is the idea behind desensitization in Type I hypersensitivity?

Answer 31

Extremely dilute solutions of antigen might cause IgG to be produced instead of IgE, reducing the reaction

Question 32

What is Type II hypersensitivity?

Answer 32

Cytotoxic

Question 33

What mediates Type II hypersensitivity, and what disease is an example?

Answer 33

Antibody-activated complement; hemolytic disease of newborns

Question 34

What is Type III hypersensitivity?

Answer 34

Complex-mediated

Question 35

Describe Type III hypersensitivity

Answer 35

Slight excess of antigen over antibody can cause Ag-Ig complexes to deposit in blood vessels and tissues; complement activates and leads to inflammatory events

Question 36

What is Type IV hypersensitivity?

Answer 36

Delayed cell-mediated

Question 37

What causes Type IV hypersensitivity?

Answer 37

T cells; first contact with a hapten primes your immune system to overreact to subsequent reactions

Question 38

What type of hypersensitivity is responsible for most types of contact dermatitis and organ rejection?

Answer 38

Type IV (delayed cell-mediated)

Question 39

In severe combined immunodeficiency, two different types of mutations occur. What types are they and what do they cause?

Answer 39

An X-linked recessive mutation causes lack of communication between B and T cells; an autosomal recessive mutation cause accumulation of deoxyadenosine, which is toxic to B and T cells.