Immunology

Question 1

what are the functions of the lymphatic system?

Answer 1

drainage of tissue
absorption and transport of fatty acids and fats
immunity

Question 2

what are the differences between lymphatic vessels and blood vessels?

Answer 2

lymphatic vessels are blind ended

cells that form lymph vessels are more delicate

Question 3

what are the 3 phases of immune defence

Answer 3

recognition of danger
production of specific weapons
transport of weapons to site of attack

Question 4

where are blood cells produced?

Answer 4

bone marrow
thymus
these are primary lymphoid organs

Question 5

what is haematopoiesis?

Answer 5

formation and activation of blood cells

Question 6

what is the function of the thymus?

Answer 6

“education” of T cells

Question 7

what is the function of secondary lymphoid organs?

Answer 7

sites of lymphocyte activation by antigens

Question 8

what 2 areas is the spleen divided into?

Answer 8

red pulp and white pulp

Question 9

what is the function of the spleen?

Answer 9

filtration of blood

Question 10

what separates red and white pulp?

Answer 10

marginal zone

Question 11

what is a high endothelial venule?

Answer 11

simple columnar cells line venules, they are slightly looser than normal venules, which allows fluid and lymphocytes to leak out of the blood vessels.

Question 12

what two zones are lymph nodes separated into?

Answer 12

B and T zones

Question 13

what effect can T cells have on B cells?

Answer 13

they can cause B cells to produce antibodies

Question 14

what are peyers patches?

Answer 14

patches of smooth cells embedded in villi covered cells.

Question 15

what does MALT stand for?

Answer 15

mucosal associated lymphoid tissue

Question 16

what covers peyers patches?

Answer 16

M cells

Question 17

what is the difference between the adaptive and innate immune system?

Answer 17

adaptive is very specific and displays immunological memory

Question 18

why does the adaptive immune system display a much larger response to an antigen in repeated exposure?

Answer 18

presence of memory cells allow a much quicker and stronger response after primary exposure

Question 19

what are the differences between active and passive immunity?

Answer 19

active immunity - conferred by a host response to a microbe or a microbial antigen
passive immunity - conferred by adoptive transfer of antibodies or T lymphocytes specific for the microbe
active immunity is the only one that generates immunological memory

Question 20

why does passive immunity not generate immunological memory?

Answer 20

because your own B cells are not involved in generating an immune response.

Question 21

where are B cells produced?

Answer 21

bone marrow

Question 22

what is the antigen receptor for a B cell

Answer 22

surface immunoglobulin (sIg)

Question 23

why is it more important to tolerize T cells than B cells?

Answer 23

B cells cannot make antibodies in response to most antigens without the help of T cells

Question 24

what is a pathogen?

Answer 24

any microorganism that causes disease.

Question 25

what part of the pathogen are antibodies specific to?

Answer 25

epitope

Question 26

what induces B cells to multiply?

Answer 26

recognition of a specific epitope on a specific antigen on a specific pathogen

Question 27

what 2 chains are antibodies separated into?

Answer 27

light chain and heavy chain

Question 28

what modification is made to antibodies after B cells multiply and produce them?

Answer 28

antibodies have a much higher affinity for epitope

Question 29

what chain does the antibody bind to ?

Answer 29

light chain

Question 30

what chain does the cell bind to?

Answer 30

heavy chain

Question 31

what do the heavy chains define?

Answer 31

classes of immunoglobulin

Question 32

how many different CLASSES of antibody are there?

Answer 32

(IGM IGD IGA IGE IGG) | 5

Question 33

what is the function of IGM

Answer 33

fixes compliment and opsonization

Question 34

function of IGG

Answer 34

good opsonizer

Question 35

function of IGA

Answer 35

protects mucosal surfaces, resistant to stomach acid

Question 36

function of IGE

Answer 36

defends against parasites, causes anaphylactic shock and allergies

Question 37

what causes antibodies to be flexible?

Answer 37

presence of a hinge between the light and heavy chains

Question 38

why does antigen bound iGm display good complement binding

Answer 38

binding to epitope causes a conformational change that allows c1 protein to bind to IgM

Question 39

what is opsonisation

Answer 39

the process of "tagging" a pathogen which causes fc receptors to "stick up" which causes the pathogen to be more susceptible to phagocytic action

Question 40

why do mast cells sometimes cause allergic reactions?

Answer 40

when mast cells encounter a pathogen they dump all of their contents onto the pathogen to neutralise it, and some of these molecules can cause allergic reaction in the host

Question 41

what ways are there to activate a B cell?

Answer 41

T cell dependent T cell independent complement activation

Question 42

how does T cell dependent activation work?

Answer 42

Signal from a clustered BCR along with a signal from a T cell in which a protein on the surface of a T cell recognises the same antigen as the B cell and then binds to a receptor on the B cell

Question 43

where do T cells go to get "educated"

Answer 43

thymus

Question 44

what are T cells reponsible for?

Answer 44

cell mediated immunity and assisting B cells

Question 45

what is the cell surface receptor of a T cell?

Answer 45

T cell receptor

Question 46

what conditions have to be met in order for TCR to recognise antigens?

Answer 46

Has to be bound to MHC protein

Question 47

What 2 classes of T cells are there?

Answer 47

helper (CD4+) and cytotoxic (CD8+)

Question 48

what kind of antigens are T cells able to recognise?

Answer 48

ANY protein peptide that a pathogen may have due to association with MHC

Question 49

What is it important for all lymphocytes to learn to do with regard to "self"

Answer 49

not to recognise "self" antigen

Question 50

what happens to T cells that are unable to interact with MHC molecules

Answer 50

death by apoptosis

Question 51

what determines what type of T cell thymocytes develop into?

Answer 51

whether it binds to MHC 1 (cytotoxic) or MHC 2 (helper)

Question 52

what happens to T cells that cannot distinguish self from non self?

Answer 52

death by apoptosis

Question 53

what is the purpose of MHC 1?

Answer 53

presents virally induced peptides to CD8+ T cells and trigger cytotoxic response

Question 54

what is the purpose of MHC 2?

Answer 54

presents exogenously produced Ag to CD4+ T cells and activate macrophages and B cells

Question 55

where is MHC 2 found?

Answer 55

on antigen presenting cells

Question 56

what decides which T cell a naive T cell turns into after MHC peptide recognition?

Answer 56

range of different chemicals acting on T cells

Question 57

Can T helper cells destroy pathogens?

Answer 57

No

Question 58

what do cytotoxic T cells release once exposed to infected/dysfunctional somatic cells?

Answer 58

perforin, which forms pores in the target cell, also releases granzyme B - induces apoptosis

Question 59

how can T memory cells be formed?

Answer 59

can arise from fully differentiated cells are from partially differentiated cells.