Immunology

Question 1

What is immunology?

Answer 1

the study of the structure and function of the immune system

Question 2

What is the Immune system?

Answer 2

Cells, tissues, and molecules that mediate resistance to infections

Question 3

What is an Immune response?

Answer 3

collective and coordinated response to the introduction of foreign substances in an individual mediated by the cells and molecules of the immune system

Question 4

What is immunity?

Answer 4

Resistance of a host to pathogens and their toxic effects

Question 5

What is the role of the immune system?

Answer 5

Defense against microbes

Defense against the growth of tumor cells

Homeostasis
destruction of abnormal or dead cells

Question 6

Which organs play a role in the immune system?

Answer 6

Tonsils and adenoids
Thymus
Lymph nodes
Spleen
Peyer’s patches
Appendix
Lymphatic vessels
Bone marrow

Question 7

Which cells play a role in the immune system?

Answer 7

Lymphocytes
T-lymphocytes
B-Lymphocytes, plasma cells
natural killer lymphocytes
Monocytes, Macrophage
Granulocytes
neutrophils
eosinophils
basophils

Question 8

Which molecules play a role in the immune system?

Answer 8

Antibodies
Complement
Cytokines
Interleukines
Interferons

Question 9

What are the 2 types of immunity?

Answer 9

Innate and acquired

Question 10

What is innate immunity?

Answer 10

Non-adaptive
First line of immune response
Relies on mechanisms that exist before infection

Question 11

What is acquired immunity?

Answer 11

Adaptive
A second line of response (if innate fails)

Relies on mechanisms that adapt after infection

Mediated by T- and B- lymphocytes

One cell determines one antigenic determinant (specificity)

Question 12

What is innate immunity based on?

Answer 12

genetic make up

Question 13

What does innate immunity rely on?

Answer 13

already formed components

Question 14

How fast is the response in innate immunity?

Answer 14

Rapid - within minutes of infection

Question 15

Is innate immunity specific, and does it have memory?

Answer 15

Not specific - same molecules / cells respond to a range of pathogens

Has no memory - same response after repeated exposure

Question 16

What is acquired immunity based upon?

Answer 16

resistance acquired during life

Question 17

What does acquired immunity rely on?

Answer 17

genetic events and cellular growth

Question 18

How fast is the response in acquired immunity?

Answer 18

Responds more slowly, over few days

Question 19

Is acquired immunity specific, and does it have memory?

Answer 19

Is specific - each cell responds to a single epitope on an antigen

Has anamnestic memory - repeated exposure leads to faster, stronger response

Question 20

Which type of immunity leads to clonal expansion?

Answer 20

Adaptive or acquired

Question 21

What are the 2 mechanisms within acquired/ adaptive immunity?

Answer 21

Cell-mediated immune response (CMIR)
Humoral immune response (HIR)

Question 22

What is involed in Humoral immune response (HIR)?

Answer 22

B-lymphocytes
mediated by antibodies
eliminate extra-cellular microbes and their toxins

Question 23

What is involved in Cell-mediated immune response (CMIR)?

Answer 23

T-lymphocytes
Eliminate intracellular microbes that survive within phagocytes or other infected cells

Question 24

What do T- cells do within a cell-mediated immune response?

Answer 24

Recognizes peptide antigen on macrophage in association with major histo-compatibility complex (MHC) molecules
Identifies molecules on cell surfaces
helps body distinguish self from non-self
T-cells differentiate into effector cells that are capable to kill infected cells

Question 25

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

Answer 25

Helper T- lymphocytes (activates phagocytes to kill microbes) Cytolytic T-lymphocyte (destroy infected cells containing microbes or microbial proteins)

Question 26

What are the 3 stages of humoral immune response?

Answer 26

B lymphocytes recognize specific antigens. They proliferate and differentiate into antibody-secreting plasma cells. Antibodies bind to specific antigens on microbes; destroy microbes via specific mechanisms Some B lymphocytes evolve into the resting state - memory cells

Question 27

What are the 5 types of antibodies?

Answer 27

IgG, IgM, IgA, IgD, IgE

Question 28

What are antibodies?

Answer 28

Belong to the gamma-globulin fraction of serum proteins Y-shaped polypeptides 2 identical heavy chains 2 identical light chains

Question 29

What is IgG responsible for?

Answer 29

70-75% of total immuniglobulin Secreted in high quantities in secondary exposures + neutralize microbes and toxins + opsonize antigens for phagocytosis + activate the complement + protect the newborn - can cross the placenta

Question 30

What is IgM responsible for?

Question 31

What is IgG responsible for?

Answer 31

Secreted initially during primary infection Cannot cross the placenta + secreted first during primary exposure + activates the complement + used as a marker of recent infection

Question 32

What is IgA responsible for?

Answer 32

Monomeric in serum Dimeric with secretory component in the lumen of the gastro-intestinal tract and in the respiratory tract + neutralizes microbes and toxins

Question 33

What is IgD responsible for?

Answer 33

Monomeric + present on the surface of B lymphocytes + functions as membrane receptor + role unclear - has a role in antigen stimulated lymphocyte differentiation

Question 34

What is IgE responsible for?

Answer 34

Mediates type I hypersensitivity Monomeric + associated with anaphylaxis + plays a role in immunity to helminthic parasites

Question 35

Immune response helps individuals defend against what?

Answer 35

microbes and cancers

Question 36

When does the immune response fail?

Answer 36

hypersensitivity reactions immunodeficiency

Question 37

What is Immunodeficiency?

Answer 37

+ Loss or inadequate function of various components of the immune system + Can occur in any part or state of the immune system - physical barrier, phagocytes, B lymphocytes, T lymphocytes, complement, natural killer cells + The immuno-compromised host has an impaired function of the immune system and is at high risk of infection

Question 38

What are hypersensitivity reactions?

Answer 38

Hypersensitivity - overreaction to infectious/chemical agents Allergy - overreaction to environmental/chemical substances Autoimmunity - overreaction to self Cause cell damage through excessive immune response to antigens