Immune and lymphatic system I Flashcards Preview

Histology Exam III Material > Immune and lymphatic system I > Flashcards

Flashcards in Immune and lymphatic system I Deck (135):
1

What kind of immunity lacks immune specificity and memory

Innate Immunity

2

What is innate immunity's "response"

Inflammation

3

What are the first responders in innate immunity

Neutrophils

4

What kind of immunity develops in response to antigens

Acquired immunity

5

Is acquired immunity more powerful than innate immunity

Yes

6

Does acquired immunity take longer to develop than innate

Yes

7

What kind of immunity displays specificity and memory

Acquired immunity

8

Temporary immunity due to donated antibodies (i.e., Transplacental passing of maternal antibodies to fetus)

Passive immunity

9

Long-lasting/permanent immunity due to self exposure to antigen resulting in memory T cells and B cells specific for antigen

Active immunity

10

Antibody-mediated immunity (Plasma cells)

Humoral immunity

11

T cells, B cells and antigen-presenting cells

Cell-mediated immunity

12

Examples of primary lymphoid organs

Thymus and bone marrow

13

Examples of secondary lymph organs

Lymph nodes, spleen, tonsils

14

Lymphocytes originate in _____ lymphoid organs and then take up residence in _____ lymphoid organs

primary, secondary

15

In primary lymphoid organs precursor cells mature into_______. Each cell is programmed to recognize

immunocompetent cells, a specific antigen

16

In secondary lymphoid organs trapped antigens

stimulate clonal expansions of mature T and B cells

17

Lymphoid tissue appears in the body as a _____ from ______ lymphoid tissue to _____ lymphoid tissue to ______

gradient, diffuse, aggregated, lymphoid organs

18

Are lymph follicles (nodules) enclosed within a capsule

No

19

Lymph follicles (nodules) occur _____ or in ______

singly or in aggregates

20

Lymph follicles (nodules) are sites of _____ localization and proliferation

B cell

21

What are the sites of B cell localization and proliferation

Lymph follicles (nodules)

22

Are lymph follicles (nodules) transient

yes

23

are spherical, tightly packed accumulations of virgin B cells and dendritic reticular cells that have not been exposed to antigens

Primary follicles (nodules)

24

Are derived from primary follicles that have been exposed to non self antigens

Secondary Follicles (nodules)

25

Are secondary follicles (nodules) present at birth

No

26

What are the two structural components of a secondary lymph follicle (nodule)

-Corona (cortex)
- Germinal Center

27

The Corona (cortex) of a secondary lymph follicle has what appearance and composition

-darker peripheral region
- Composed of densely packed B lymphocytes

28

The Germinal Center of a secondary Lymph Follicle (nodule) has what appearance and composition

-Central, lighter stained region
-Composed of B lymphocytes, memory B cells, plasma cells, dendritic reticular cells which function as antigen-presenting cells

29

Explain the vascular supply of a secondary lymph follicle (nodule)

-Arteriole and venue supply the cortex
- Another arteriole and venue supply the center
- Lymph Capillaries are not present

30

Diffuse lymphoid tissue is made up of

scattered clusters of plasma cells, macrophages, and lymphocytes located in the CT Stroma and various other sites

31

Subcutaneous-associated lymphoid tissue is found in the

papillary layer of the dermis

32

Give 3 examples of Lamina propria- associated lymphoid tissues includes

MALT= Mucosal-associated lymphoid tissue
BALT= Bronchial-associated lymphoid tissue
GALT= Gut-associated lymphoid tissue

33

Aggregated lymphoid tissue is located

beneath and in contact with the epithelium

34

Examples of aggregated lymphoid tissue

Various tonsils and peer's patches in the ileum

35

3 types of antigen presenting cells

macrophages (monocyte derived)
dendritic cells (monocyte derived)
follicular dendritic cells (lymph node-derived)

36

T cells differentiate into

Helper T cells and Cytolytic T cells

37

What are two kinds of lymphocytes

B and T cells

38

All immune system cells originate in the

bone marrow

39

Immature T cells travel to the

Thymus

40

B-Cells travel to

Specific regions in lymphoid tissue

41

The maturation of B cells involves the appearance of certain cell surface receptors such as

-IgM and IgD
- MHC class II proteins
- Complement receptors
- Ig Fc Receptors

42

What are the 5 classes of antibodies

-IgA, IgD, IgG, IgM, IgE

43

Stem B cells in the bone marrow proliferate and mature in a microenvironmental niche provided by bone marrow stream cells producing _________

Interleukin-7 (IL-7)

44

The antigen receptor complex is composed of

(IgM or IgD) interacting with two additional proteins linked to each other (IgA and IgB)

45

Explain B-cell maturation

Stem B cells in the bone marrow proliferate and mature in a microenvironmental niche provided by bone marrow stream cells producing Interleukin-7 (IL-7)---> This makes a pro B cells into a pre-B cell----> which then express either IgM or IgD along with Iga and IgB thus becoming a immature B cell----> self antigens then test the B cell antigen receptor complex and if it binds to strongly then it undergoes apoptosis and if not then it is enters the circulation as a mature B cell---> enters CT as a plasma cell

46

Antibody structure

-Light and Heavy Chains
- Highly variable regions
- Fab fragment
- Recognizes antigen
- Less variable regions
- Fc Fragment
- Binds antibody to cells

47

IgA is found in

Saliva, milk, GU and respiratory tracts

48

IgD is found on

surface of B cells traveling to lymphoid organs

49

What is the major Ig in blood

IgG

50

What Ig is responsible for most antibody activity

IgG

51

IgE is associated with

Allergic responses

52

What is the first antibody class expressed by developing B cells

IgM

53

What is the function of the Major Histocompatibility Complex

Main function of MHC products is the presentation of antigenic peptides to T cells

54

What are the two classes of MHC gene products

MHC I
MHC II

55

MHC I is expressed on

the surface of all cells except trophoblast and red blood cells

56

MHC II is expressed on

the surface of B cells and antigen-presenting cells

57

CD8+ T cells recognize

peptide fragments of foreign proteins bound to MHC class I on the surface of cells

58

CD8 is a member of the

Ig superfamily

59

Both the ____ and the ______ are required for the binding of MHC class I protein fragments

CD8, T cell antigen receptor

60

____ recognize peptide fragments of foreign proteins bound to MHC class II proteins on surface of APCs (antigen presenting cells)

CD4+ T cells

61

Pre-T cells develop in

Bone marrow

62

T cells travel to the ____ to complete maturation

Thymus

63

The _____ gene locus expresses gene products responsible for the rejection of grafted tissue between two genetically incompatible hosts

MHC (Major histocompatibility complex)

64

All nucleated cells express class ____ MHC molecules

I

65

Class II MHC molecules are mainly restricted to

antigen-presenting cells (macrophages, dendritic cells, and B cells), thyme epithelial cells of the thymus, and endothelial cells

66

CD4+ T cells recognize antigens

bound to MHC class II molecules

67

What are "double-negative" T-cells

Precursor T-Cells that enter cortex of the thymus from the bone marrow but lack surface molecules typical of a mature T-cell: Thymus Cell receptor (TCR), and CD4 and CD8 coreceptors

68

Where are double negative T-Cells found

in the cortex of the thymus

69

Where are double-positive T-cells found

deep in the cortex of the thymus

70

What are double positive T-Cells

After interacting with Thymic epithelial cells T cells proliferate, differentiate, and express thyme cell receptor (TCR), and the coreceptors CD4 and CD8

71

Where are Single-positive T cells first found

in the medulla of the thymus

72

What happens to Double-positive T cells that cannot recognize self-MHC

fail the positive selection and are discarded (clonal deletion)

73

What happens to Double positive T cells that recognize self-MHC

They mature and express one of the two coreceptor molecules (CD4 or CD8) and become "single-positive" T cells (clonal selection)

74

CD4+ T cells function

Assist CD8+ cells differentiation
assist B cell differentiation

75

CD8+ recognize antigens bound to

MHC class I molecules

76

Explain how a CD8+ cytolytic T cell kills?

1.) binds to antigen-presenting cell and is activated by interleukin-1 produced by the antigen-presenting cell (paracrine mechanism), and by interleukin-2, produced by the cytolytic T cell (autocrine mechanism). The cytolytic T cell divides by mitosis to increase the cell population
2.) In the presence of an antigen-presenting cell containing a pathogen antigen (a virus), cytolytic T cells release protein pore-forming perforin to kill the infected target cell. The CD8+ cytolytic T cell protects itself with protectin, a cell surface molecule that binds perforin. Perforin facilitates the delivery of pro-apoptotic granzyme B proteases to the target cell.
3.) Fas ligand, released by the cytolytic T cell and bound to the Fas receptor, together with granzyme destroy target cell by apoptosis

77

What do CD8+ T Cells (cytolytic T cells) release

Perforin
Fas Ligand

78

What is Fas Ligand

Binds to the Fas receptor on a cell and and triggers apoptosis

79

What are the mediators of cellular immunity

CD8+

80

What is the function of Perforin released by CD8+ T cells

Induces cell membrane damage to the target cell

81

CD16+ T cells are better known at

Natural Killer (NK) cells

82

Natural killer cells destroy

tumor cells

83

CD16+ cells are activated by

Tumor cell antigens
T-helper cells release Cytokines

84

Interleukin-2 effect on NK cells

Stimulates proliferation of NK cells

85

Interferon-gamma effect on NK cells

Activates NK cells

86

Macrophage activating factor (MAF)

Activates Macrophages

87

TNF-beta (tumor necrosis factor)

kills tumor cells directly

88

Activated T cells undergo mitosis: which leads to

-some daughter cells becoming memory cells
-some daughter cells secrete interleukins

89

T cells attract

B cells

90

B cells have access to what

Free antigens

91

B cells undergo mitosis leading to

-some daughter cells becoming plasma cells
- Secrete appropriate antibodies
- Some daughter cells become memory cells

92

what is an epitope

antigenic property that is noticed by the immune system

93

The complement system is an array of about ___ serum proteins which are synthesized in the ___ and found in the blood

20, liver

94

Classic pathway of complement system

Cascade is activated by antibody binding to pathogen

95

Alternate pathway fo complement system

Cascade is directly activated by the pathogen

96

The complement system facilitates

inflammatory responses

97

The complement cascade (either pathway) involves

coating the pathogen with complement initiating the cascade

98

C1 (the first complement factor in the cascade) is made up of how many subcomponents and what are there names

3, C1q, C1r, C1s

99

Immunoglogulins bind to surface of

pathogen

100

C1q bind to ___ region of Ig

Fc

101

The binding of C1q to Fc region of Ig

activates C1r, which activates C1s, which in turn generates a serine protease that initiates complement cascade

102

Protease C1s cleaves complement protein ____ and ___ into what

Protease C1s cleaves C4 into C4a and C4b
Protease C1s cleaves C2 into C2a and C2b

103

C2b binds to C4b, which is already bound to the pathogen to make

C4b-2b complex or C3 Convertase

104

C3 convertase cleaves

C3 into C3a and C3b

105

one C3 converts can cleave about ______ C3 molecules

1,000

106

Several C3b molecules bind to C3 convertase to form

C4b-2b-3b complex or C5 convertase

107

protein C5 binds to the C3b component of ______ and is cleaved into

C5 convertase, C5a and C5b

108

once C5 is bound to C5 convertase the

opsonization of the pathogen is complete

109

When C6,C7, and C8 are added to the C4b-2b-3b-5b complex they from

pores in the membrane of the pathogen (lytic pore called the membrane attack complex (MAC))

110

Activation of the membrane attack complex (MAC) on the pathogen leads to

perforations and lysis

111

The complement cascade results in:

-activation of MAC (membrane attack complex) on the pathogen leading to perforations and lysis
- production of opsonins, which are coatings that make the antigens more palatable to phagocytes
- Release of chemotactic agents (chemokines) which attract phagocytes (chemotaxis) to the areas of infection or inflammation

112

What are opsonins

coatings that make the antigens more palatable to phagocytes

113

Parenchyma consists of

the cells that typically pack areas of the lymphoid organ
- mostly lymphocytes

114

Stroma consists mostly of

reticular fibers and cells, including undifferentiated cells and fixed and free macrophages

115

size of lymph nodes

Varies from 1-25 mm in diameter

116

Lymph node composition

-Capsule
-Trabeculae
- Cortex
-medulla
-Hilus

117

What is the hilus of a lymph node

-Entry and exit point for vessels
-efferent lymphatic vessels as well as arteries and veins enter through the hilus
- Afferent lymphatic vessels enter the convex side of the node

118

Afferent lymphatic vessels pierce the ____ and open into the _____ of a lymph node

capsule, subcapsular sinus

119

______ arise from the sub capsular sinus and penetrate the cortex of the lymph node

paratrabecular sinuses

120

The ______ are confluent with the medullary sinuses at the hilum and penetrate the capsule to join the efferent lymphatic vessel of the lymph node

subcortical sinuses

121

The capsule of the lymph node is composed of

dense collagen fibers, some elastic fibers, and smooth muscle fibers

122

The outer cortex of a lymph node contains

lymph follicles (nodules)

123

Lymph follicles (nodules) of the outer cortex in a lymph node contain

- B cells
- Follicular dendritic cells
- Migrating dendritic cells

124

Secondary lymph follicles (nodules) have

a mantle and Germinal center

125

Primary lymph follicles (nodules) lack

a mantle and germinal center

126

What is the difference between a primary and secondary lymph follicle (nodule)

secondary have a mantle and germinal center
primary lack a mantle and germinal center

127

The deep (inner) cortex of a lymph node composition

-contains T cells (CD4 helper T cells), macrophages

- high endothelial venules (HEVs)
- which is the port of entry for circulating differentiated lymphocytes to seed lymph node

128

Composition of the medulla of a lymph node

-irregular arrangement of loose medullary sinuses and dense medullary cords
- Sinuses are lined with macrophages
- Cords consist of blood vessels, lymphoblasts, and plasma cells

129

medullary cords of lymph node consist of

blood vessels, lymphoblasts, and plasma cells

130

Medullary sinuses of lymph nodes are lined by

macrophages

131

The medulla of a lymph node is the site of

lymphocyte reentry into lymph stream

132

what is the site of lymphocyte reentry into lymph stream

Medulla of a lymph node

133

The thymus dependent areas of a lymph node are

in the subcortical and deeper medullary regions

134

What is the most important Opsonin

C3b

135

What is the port of entry for circulating differentiated lymphocytes to seed lymph node (note located in the deep inner cortex)

High endothelial venules (HEVs)