Components of the Immune System

Question 1

where do all immune cells come from?

Answer 1

hematopoeitic stem cells

Question 2

what do hematopoeitic stem cells do?

Answer 2

differentiate into myeloid progenitor cells and lymphoid progenitor cells

Question 3

what do myeloid progenitor cells become? (5)

Answer 3

1. granulocytes
2. monocytes
3. macrophages
4. platelets
5. erythrocytes

Question 4

what do lymphoid progenitor cells become? (3)

Answer 4

1. lymphocytes
2. dendritic cells
3. natural killer cells

Question 5

what do granulocytes contain?

Answer 5

cytoplasmic granules

Question 6

what happens to granulocytes when they come into contact with antigen?

Answer 6

the contents of their cytoplasmic granules are released and will perform different functions based on cell type

Question 7

what are the 4 granulocytes? which of those 4 is NOT a white blood cell?

Answer 7

1. neutrophils
2. eosinophils
3. basophils
4. mast cells- NOT white blood cells

Question 8

where are neutrophils found?

Answer 8

circulate in bloodstream for a short period of time (less than 10 hours) and then migrate into tissues, where they live up to 10 days and then die

Question 9

what is the function of neutrophils?

Answer 9

1. perform phagocytosis of antigen

2. secrete contents of granules which will attract other immune cells to site of infection

Question 10

what is the most abundant of white blood cells, making up over 50% of circulating WBCs?

Answer 10

neutrophils

Question 11

why are neutrophils the first responders in an infection?

Answer 11

they are already in the tissues at time of infection

Question 12

do birds have neutrophils? if no, what do they have instead?

Answer 12

not neutrophils; have heterophils which are the same as neutrophils; just stain differently

Question 13

what are eosinophils specialized for?

Answer 13

to fight of multi-cellular parasites

Question 14

what is the function of eosinophils?

Answer 14

release cytoplasmic granules in response to multicellular parasites (like worms)

Question 15

how do eosinophils begin their function?

Answer 15

they bind to PAMPs on worms to recognize antigen and then release granules to kill

Question 16

are eosinophils common?

Answer 16

no; they only make up 2-4% of circulating WBCs

Question 17

how do basophils work?

Answer 17

by binding to antigen-antibody complexes and releasing granules

Question 18

what do basophils have receptors for?

Answer 18

antibodies

Question 19

what is the major protein in the granules of basophils?

Answer 19

histamine

Question 20

what does histamine from basophils do? (basophil function)

Answer 20

1. makes blood vessel walls more permeable to allow recruitment of more immune cells to site of infection
2. combat parasitic infections

Question 21

what is the least common WBC, making up less than 1% of circulating WBCs?

Answer 21

basophils

Question 22

what are basophils characterized by on a slide?

Answer 22

purple-staining granules

Question 23

what is a side effect of histamine release?

Answer 23

allergy symptoms

Question 24

what is the function of Mast Cells? (they’re copycats)

Answer 24

bind to antigen-antibody complexes and release histamine from cytoplasmic granules (copying basophils); also involved with parasitic infections

Question 25

where are mast cells found?

Answer 25

in tissues! not circulation bc they are not a WBC!!

Question 26

what are antigen-presenting cells (APCs)?

Answer 26

cells of innate immune response that bridge the gap between innate and adaptive immune response and activate T lymphocytes

Question 27

are monocytes themselves APCs?

Answer 27

no; they mature into APCs

Question 28

where are monocytes found?

Answer 28

travel in the bloodstream and then migrate into tissues to mature into macrophages

Question 29

what do monocytes mature into? do they do much for immunity as monocytes?

Answer 29

macrophages; no

Question 30

what are the 2 functions of macrophages?

Answer 30

1. perform phagocytosis | 2. process antigen and present it on cell surface (becoming APCs)

Question 31

how do macrophages perform their function?

Answer 31

by binding to antibody-antigen complexes, enhancing phagocytosis

Question 32

what is opsonization?

Answer 32

tagging an antigen for further elimination

Question 33

what do antibodies serve as?

Answer 33

opsonins that mark antigen for immune cells

Question 34

what are the 2 types of macrophages?

Answer 34

1. tissue-specific macrophages | 2. inflammatory macropages

Question 35

what are tissue-specific macrophages?

Answer 35

long-term residents in tissues throughout the body that are NOT derived from monocytes

Question 36

give 3 examples of tissue-specific macrophages

Answer 36

1. osteoclasts 2. microglia 3. Kupffer cells

Question 37

what are inflammatory macrophages?

Answer 37

derived from monocytes, enter tissue in response to infection

Question 38

what are the 2 APCs?

Answer 38

1. macrophages | 2. dendritic cells

Question 39

what are the 3 functions of dendritic cells?

Answer 39

1. perform phagocytosis 2. receptor-mediated endocytosis and pinocytosis 3. process antigen and present on cell surface (becoming APCs)

Question 40

where are dendritic cells found?

Answer 40

in tissues, NOT the bloodstream

Question 41

what are the 3 major types of agranulocytes in the immune system?

Answer 41

1. helper T cells 2. cytotoxic T cells 3. B lymphocytes

Question 42

how are lymphocytes distinguished since they all look the same?

Answer 42

based on the proteins expressed on the cell surface

Question 43

how are the surface proteins of lymphocytes named?

Answer 43

based on cluster of differentiation (CD) nomenclature

Question 44

what is the CD nomenclature of helper T cells and what is their function?

Answer 44

1. CD4+ | 2. activate other immune cells

Question 45

what is the CD nomenclature of cytotoxic T cells and what is their function?

Answer 45

1. CD8+ | 2. kill virally-infected cells

Question 46

what do ALL T cells have? what is the function and result of that function?

Answer 46

a T Cell Receptor (TCR) that recognize antigen; are antigen specific and their binding action to antigen leads to clonal selection

Question 47

what surface protein to B cells have?

Answer 47

B Cell Receptor (BCR)

Question 48

what is BCR? function and result of that function?

Answer 48

B cell receptor; a non-soluble antibody attached to B cell surface that is antigen specific and its binding action to antigen results in clonal selection

Question 49

what are plasma cells?

Answer 49

activated B cells!

Question 50

do plasma cells have BCRs?

Answer 50

nope

Question 51

what do plasma cells do?

Answer 51

secrete antibody that binds antigen for opsonization

Question 52

are NK cells antigen specific?

Answer 52

nope; they are part of innate immunity

Question 53

what do NK cells do?

Answer 53

attack and kill abnormal cells

Question 54

what super cool thing can NK cells do that mimics adaptive immunity?

Answer 54

they can bind free antibody and coat themselves in pathogen-specific antibody so that when that antibody binds antigen, NK cells release cytotoxic material to kill the pathogen

Question 55

what are primary lymphoid organs?

Answer 55

locations where immune cells develop and mature

Question 56

what are the 3 primary lymphoid organs and what happens in each?

Answer 56

1. Bone Marrow: B lymphocyte development in mammals 2. Bursa of Fabricius: B lymphocyte development in BIRDS 3. Thymus: T cell development in all animals

Question 57

where is the Bursa of Fabricius located?

Answer 57

right off the cloaca

Question 58

what happens to the Bursa of Fabricius after 6 months of age and what does this mean for birds?

Answer 58

it begins regressing so eventually birds have no way to replenish B lymphocyte supply

Question 59

what are seconday lymphoid organs?

Answer 59

locations where the adaptive (lymphocyte) immune response is initiated

Question 60

where is the innate immune response always inititated?

Answer 60

at the site of infection

Question 61

what are the 3 secondary lymphoid organs?

Answer 61

1. Lymph nodes 2. spleen 3. Mucosa-associated lymphoid tissue (MALT)

Question 62

what happens in lymph nodes?

Answer 62

lymphocytes encounter antigen from local tissues

Question 63

what happensin the spleen?

Answer 63

lymphocytes encounter antigen from the bloodstream

Question 64

what happens in the MALTs?

Answer 64

activation of immune response at site of antigen entry

Question 65

give 4 MALTs and their locations

Answer 65

1. GALT: gastrointestinal 2. NALT: nasal 3. BALT: bronchi 4. SALT: skin

Question 66

what are tertiary lymphoid organs?

Answer 66

the site of infection; lymphocytes travel to this area to fight off infection