Introduction

Question 1

what does a cytokine do?

Answer 1

mediates inflammatory and immune reactions

Question 2

what is the physiologic function of the immune system?

Answer 2

prevent and eradicate infections and eradicate cancers

Question 3

does an antigen induce a specific immune response?

Answer 3

not always

Question 4

what are the principal components of innate immunity?

Answer 4

anatomical and chemical barriers
effector cells
inflammation

Question 5

what are the most important professional antigen presenting cells?

Answer 5

dendritic cells

Question 6

what do neutrophils do?

Answer 6

kill extracellular pathogens
phagocytose

Question 7

what secretes cytokines?

Answer 7

macrophages

Question 8

what are the two professional antigen presenting cell types?

Answer 8

dendritic cells and macrophages

Question 9

how do macrophages deal with pathogens/foreign antigens?

Answer 9

capture them, lyse them, and present them to T cells

Question 10

what cells are important in linking innate and adaptive immune responses?

Answer 10

dendritic cells

Question 11

true/false: macrophages and neutrophils can phagocytose intracellular pathogens if those pathogens are present in extracellular spaces

Answer 11

true

Question 12

what is phagocytosis and killing of microbes?

Answer 12

when a phagocyte binds and phagocytoses a pathogen or surface molecule, then entraps it in the phagosome, which fuses with the lysosome to form a phagolysosome. Enzymes of it kill the microbe

Question 13

what cells are phagocytes?

Answer 13

neutrophils, macrophages, and dendritic cells

Question 14

what reactions do basophils contribute to?

Answer 14

inflammation and allergic reactions

Question 15

what do eosinophils do?

Answer 15

secrete the contents of their granules to damage parasitic membranes

Question 16

what cells have the most heavily granulated cytoplasm?

Answer 16

mast cells

Question 17

what cells directly kill other cells?

Answer 17

natural killer (NK) cells

Question 18

how do natural killer cells kill other cells?

Answer 18

secrete perforin and granzymes (proteins)
perforin makes holes in the cell membrane to allow granzymes through, which induce apoptosis

Question 19

what is hypersensitivity?

Answer 19

when inflammation goes too far and causes a lot of damage to the host’s tissues, even death

Question 20

what are the first four hallmark signs of inflammation?

Answer 20

rubor (redness- increased blood flow), calor (heat- increased blood flow), tumor (swelling- edema and proteins), dolor (pain- stimulation nerve endings)

Question 21

do arteries and arterioles or venules contribute to inflammation (extravasation)?

Answer 21

venules

Question 22

what are the effector cells of adaptive immunity?

Answer 22

B and T lymphocytes (B and T cells)

Question 23

what cells can be recruited into an inflamed site?

Answer 23

neutrophils (primarily), lymphocytes, and monocytes and other cells

Question 24

what do T cells recognize?

Answer 24

only protein antigens

Question 25

what do B cells recognize?

Answer 25

protein, carbohydrate, and lipid antigens the whole Baboodle

Question 26

what cells express antigen receptors?

Answer 26

B and T cells

Question 27

what are the two main characteristics of adaptive immunity?

Answer 27

specificity/specific immunity and memory/acquired immunity

Question 28

what is an immunogen?

Answer 28

an antigen that always induces an immune response

Question 29

what are hapten and carrier?

Answer 29

a small chemical on a macromolecule to induce an immune response

Question 30

what are epitopes or antigenic determinants?

Answer 30

regions against which immune responses are directed

Question 31

what are the two types of epitopes?

Answer 31

linear and discontinuous/conformational

Question 32

what is the basis of diversity with lymphocytes?

Answer 32

an unvaccinated animal will have clones of lymphocytes with different specificities, for antigens they have never been exposed to

Question 33

what is lymphocyte repertoire?

Answer 33

the total number of antigenic specificities of the lymphocytes an individual has

Question 34

true/false: immunocompetent dogs that have never been exposed to antigens of canine parvovirus have a small fraction of B cells with B cell receptors specific to canine parvovirus

Answer 34

true

Question 35

true/false: ten dogs vaccinated a month back for the first time against canine parvovirus, but not the 40 unvaccinated dogs, have a small fraction of B cells with B cell receptors specific to canine parvovirus

Answer 35

false. they all have some

Question 36

true/false: ten dogs vaccinated a month back for the first time against canine parvovirus, but not the 40 unvaccinated dogs, have memory B cells with B cell receptors specific to canine parvovirus

Answer 36

true

Question 37

do dogs have a small fraction of B cells with B cell receptors specific to feline immunodeficiency virus?

Answer 37

yes

Question 38

do naive or memory cells respond more rapidly and vigorously to antigen challenge?

Answer 38

memory cells

Question 39

what is tolerance?

Answer 39

self recognition so that you do not kill your own healthy cells

Question 40

what are the two types of adaptive immunity?

Answer 40

humoral immunity cell-mediated or cellular immunity

Question 41

what cells produce antibodies or immunoglobulins that mediate humoral immunity?

Answer 41

B cells

Question 42

do naive B cells secrete antibodies into the extracellular space?

Answer 42

no

Question 43

what are plasma cells?

Answer 43

terminally differentiated, non-dividing effector B cells

Question 44

what does the activated B cell (no longer naive) differentiate into?

Answer 44

effector B cells (plasma cells) and long-lived memory B cells

Question 45

why do we need antibodies?

Answer 45

they play a major role in defense against microbes and their toxins

Question 46

do T cells secrete their T cell receptors?

Answer 46

no, they only express 10^5 identical T cell receptors

Question 47

when do T cell receptors on T cells recognize antigens?

Answer 47

when antigens are presented to them by professional antigen presenting cells

Question 48

do the major histocompatibility complex molecule of antigen presenting cells present carbohydrates or lipids?

Answer 48

no- only proteins

Question 49

what are the two types of effector T cells?

Answer 49

helper (helper through cytokines) and cytotoxic (killer function- kill cells infected)

Question 50

how do T cells kill cells?

Answer 50

perforin and granzymes

Question 51

why are T helper cells considered a part of cellular immunity?

Answer 51

they provide help to various immune cell types including macrophages, eosinophils and T cytotoxic cells

Question 52

what are the effector cells of innate immunity?

Answer 52

macrophages neutrophils dendritic cells natural killer cells mast cells eosinophils basophils

Question 53

true/false: a pathogen always expresses more than one antigen, each bearing many epitopes

Answer 53

true

Question 54

from what do lymphocyte precursors arise from?

Answer 54

pluripotent stem cells in bone marrow

Question 55

where do lymphocyte precursors undergo maturation and development?

Answer 55

primary lymphatic organs

Question 56

where do T cells go to become immunocompetent (still naive)?

Answer 56

thymus

Question 57

where do B cells go to become immunocompetent (still naive)?

Answer 57

bone marrow cloacal bursa Peyer's patches

Question 58

what cells replace the connective tissue in most lymphoid organs?

Answer 58

epithelial cells (epithelioreticular cells)

Question 59

what do epithelial cells do that replace the connective tissue in the thymus?

Answer 59

mechanical support secrete cytokines sheath blood vessels

Question 60

where are Hassall's corpuscles found? what cells are they made up of?

Answer 60

thymus epithelioreticular cells

Question 61

does the thymus have efferent and/or afferent lymphatics?

Answer 61

efferent only

Question 62

what is a thymoma?

Answer 62

a malignancy of thymic epithelial cells after sexual maturity

Question 63

what makes up the outer layer of the cloacal bursa?

Answer 63

epithelium

Question 64

what promotes B cell differentiation in the cloacal bursa?

Answer 64

epithelial (reticular) cells

Question 65

where are Peyer's patches found (primary lymph organ)?

Answer 65

distal ileum of small intestine ruminants, carnivores, pigs

Question 66

where do B cell precursors start in the bone marrow?

Answer 66

near endosteum of bone, move toward venous sinuses

Question 67

what is the purpose of secondary lymphoid organs?

Answer 67

immunosurveillance and response to foreign antigens

Question 68

where is diffuse lymphoid tissue found prominently?

Answer 68

lamina propria of tubular organs

Question 69

what is found in secondary nodules of lymphoid tissue?

Answer 69

large proliferating lymphocytes on inside (germinal center), small naive on outside (mantle zone)

Question 70

are interfollicular areas B cell or T cell rich?

Answer 70

T cell rich

Question 71

what are the tonsils?

Answer 71

secondary lymphoid tissue in oro- and nasopharynx

Question 72

does the tonsil have afferent lymphatics?

Answer 72

no

Question 73

where are Peyer's patches most commonly found (secondary lymph organs)?

Answer 73

jejunum and proximal ileum

Question 74

what do microfold cells do?

Answer 74

pinocytose particulates in lumen and present them to lymphocytes and dendritic cells in basolateral pockets

Question 75

what lymphatic organs have afferent lymphatics?

Answer 75

lymph nodes

Question 76

where are B cells and T cells in the lymph nodes?

Answer 76

B cell superficial cortex T cells deeper cortex in zones medulla: cords and sinuses

Question 77

what are sinuses for in lymph nodes?

Answer 77

allows lymph to pass into sinus allows lymph to pass into parenchyma macrophages hunt for antigen

Question 78

what type of vessels are found in the paracortex of lymph nodes after the capillaries?

Answer 78

high endothelial vessels make up venules

Question 79

how do most lymphocytes enter the lymph node?

Answer 79

via high endothelial venules lines by tall, simple cuboidal endothelium

Question 80

how do B cells leave the lymph node in an immune response?

Answer 80

medullary cords to medullary sinuses

Question 81

what makes up the capsule of the spleen?

Answer 81

mesothelium, connective tissue, +/- smooth muscle

Question 82

what is in the white pulp of the spleen?

Answer 82

organized lymphoid tissue: periarteriolar lymphatic sheath and lymphoid nodules

Question 83

do B cells or T cells predominate near the periarteriolar lymphatic sheath?

Answer 83

T cells

Question 84

how do lymphocytes get into the spleen?

Answer 84

migrate from capillaries in zone between white pulp and red pulp

Question 85

what species have nonsinusoidal spleens (no splenic sinuses: open circulation)?

Answer 85

cats, horses, oxes, pigs

Question 86

true/false: sinuses function as a mechanical filter and pinch off red blood cell inclusions

Answer 86

true

Question 87

what removes abnormal red blood cells in nonsinusoidal spleens?

Answer 87

macrophages

Question 88

what do antigens do?

Answer 88

bind to microbes outside cells, neutralize them, facilitate their removal

Question 89

what are the phagocyte types?

Answer 89

neutrophils, macrophages, and dendritic cells

Question 90

what cell type predominantly surrounds central arteries in spleens?

Answer 90

periarteriolar lymphatic sheath of T lymphocytes

Question 91

where are sheathed capillaries in spleens and what surrounds them?

Answer 91

in red pulp, surrounded by periarteriolar macrophage sheath

Question 92

how do you distinguish between a tonsil slide and a lymph node slide?

Answer 92

tonsil will have epithelium over at least half of it (stratified squamous epithelium)

Question 93

what cells are in germinal centers in lymph nodes?

Answer 93

large activated B cells

Question 94

how do most lymphocytes enter the lymph node?

Answer 94

high endothelial venules

Question 95

where are T cells found in lymph nodes?

Answer 95

surrounding B cell nodes (germinal center with corona)

Question 96

is the thymus a primary or secondary lymphoid organ?

Answer 96

primary

Question 97

how do lymphocytes enter and leave the thymus?

Answer 97

enter via cortical capillaries leave via post-capillary venules or efferent lymphatics

Question 98

what tissue type is a prominent component of the splenic parenchyma and trabecula?

Answer 98

smooth muscle

Question 99

where are high endothelial venules found?

Answer 99

lymph nodes