Secondary Lymphoid Organs Flashcards Preview

Immunology Exam Two > Secondary Lymphoid Organs > Flashcards

Flashcards in Secondary Lymphoid Organs Deck (76):
0

Where do B cells and T cells originate?

Bone marrow

1

Where do B cells mature?

Bone marrow

2

Where do T cells migrate to mature?

Thymus

3

What are the secondary lymphoid organs?

Lymph nodes (500-600 in the body), spleen, and mucosal-associated lymphoid tissue (MALT)

4

Where does the recognition phase of the adaptive immune response occur?

In the secondary lymphoid organs (lymph nodes usually)

5

How do secondary lymphoid organs help lymphocytes survive and continue to recirculate even when they don't find their cognate antigen?

By providing them with sustaining signals

6

Are lymphoid follicles present among all secondary lymphoid organs?

Yes, very common

7

What type of lymphoid follicle involves a loose network of follicular dendritic cells rich in naive and memory B cells?

Primary

8

Which type of lymphoid follicle occurs after antigen stimulation and includes a germinal center specific for replication and differentiation?

Secondary

9

What is the difference between the antigen presenting dendritic cells and the follicular dendritic cells?

Follicular dendritic cells are stationary and remain in the lymph node unlike the traveling antigen presenting dendritic cells

10

Do the B cells of a primary lymphoid follicle "island" likely have different BCRs or are they likely to all be the same?

They are most likely all different which makes the proliferation aspect critical to increase amount of B cells with the same BCRs

11

What is the normal function of follicular dendritic cells?

Catch and display opsonized antigen to B cells with high affinity receptors

12

Follicular dendritic cells may be related to what other kind of cell?

Fibroblasts

13

Are follicular dendritic cells a type of white blood cell?

Noooo

14

What conditions can result in ectopic follicular dendritic cells?

Autoimmune and inflammatory conditions

15

Are follicular dendritic cells a part of the parenchymal or stromal cells of the secondary lymphoid organ?

Stromal

16

Follicular dendritic cells have receptors that bind antigens to what region of antibodies?

Fc (constant tail region)

17

Can follicular dendritic cells bind to complement proteins?

Yes

18

What is the purpose of the follicular dendritic cells attaching to and holding opsonized antigens?

BCRs cluster and crosslinks more easily enabling more activation

19

Germinal centers are associated with which type of lymphoid follicle?

Secondary

20

Are all the B cells in the germinal center identical clones?

Yes

21

The formation of germinal centers is associated with what appearance of lymph nodes?

Visibly swollen lymph nodes

22

The many proliferating B cells involved with a germinal center gives off what microscopic appearance?

"Dark zone"

23

What happens to the lower affinity BCR B cells of the germinal centers?

They die by apoptosis and are eaten by macrophages

24

Where does class switching of antibodies occur?

In the "dark zone" of the germinal centers

25

In those with T cell deficiency, what is the only antibody class that can be created by B cells?

IgM

26

Peyer's patches and the appendix are associated with what kind of lymphoid tissue?

GALT (gut-associated lymphoid tissue)

27

The tonsils and adenoids are associated with what type of lymphoid tissue?

NALT (nasal-associated lymphoid tissue)

28

Which type of lymphoid tissue is associated with the respiratory system?

BALT (bronchial-associated lymphoid tissue)

29

All lymphoid tissue types (GALT, BALT, NALT) possess what?

Lymphoid follicles

30

How can an antigen enter the lymph node?

Via blood or lymph

31

How does blood enter the lymph node?

Via arterioles

32

Lymphocytes leave the blood and enter the lymph node via what structures?

High endothelial venules (HEV)

33

T cells are more common in what area of the lymph node?

Paracortex

34

Macrophages are found in what specific area of the lymph node?

Subcapsular/marginal sinus

35

What is the B cell area of the lymph node?

Cortex

36

What surrounds the lymph node?

Capsule

37

Where does the lymph first enter the lymph node?

Subcapsular/marginal sinus (that is lined with macrophages)

38

Where are the primary and secondary lymphoid follicles (filled with B cells) located in the lymph node?

Cortex

39

What is the area located beneath the cortex and paracortex of the lymph node?

Medulla (medullary sinus)

40

What are the afferent lymph vessels?

Incoming lymph vessels to the node

41

What are efferent lymph vessels?

Outgoing lymph vessel to the node

42

How do lymphocytes enter the lymph node specifically?

Via arteriole or incoming lymph

43

What is the entry point for B and T cells to enter secondary lymphoid organs from the blood?

High endothelial venules (HEV)

44

What is the structure of HEV compared to actual endothelial cells?

HEV are columnar in shape and have gaps in between to offer more room for the passage of cells compared to actual endothelial tissue

45

At rest, what percentage of cardiac output goes through the spleen?

5%

46

How long does it take to screen all the blood in your body?

30 minutes

47

What kind of lymph vessels are not seen bringing lymph to the spleen?

No afferent lymphatics

48

What drains the thoracic duct?

Cisterna chyli

49

What type of cells dominate in the marginal sinuses?

Macrophages

50

Blood entering the spleen must filter back out to what vein?

Splenic vein

51

What area of the spleen consists of B cells?

Area between the periarteriolar lymphocyte sheath (PALS) and marginal sinus

52

In what location of the spleen are T cells dominant?

Periarteriolar lymphocyte sheath (PALS)

53

Does red or white pulp make up the bulk of the spleen?

Red

54

Where is the site of red blood cell destruction of the spleen?

Red pulp

55

What occurs during RBC destruction?

Hemoglobin: globin is broken down into individual amino acids and heme is broken down into bilirubin

56

What effect does vagal stimulation have on the macrophage response in the spleen?

Inhibition (cholinergic anti inflammatory reflex)

57

Where is the white pulp of the spleen located?

Within the red pulp

58

Where is the periarteriolar lymphocyte sheath?

Surrounding the center arteriole

59

What surrounds both the PALS and the follicle?

Perifollicular zone

60

The PALS is made up of primarily what kind of cells?

T cells

61

Follicles are made primarily of what kind of cells?

B cells (full of germinal centers, B cell corona, and marginal zone)

62

Adults have about how many Peyer's patches?

200

63

What is the function of M cells (microfold cells)?

Enclose intestinal antigens in vesicles called endosomes

64

Do M cells posses microvilli or mucus?

No

65

After an antigen is packaged in an endosome by an M cell in the intestines, where can it be taken?

To the Peyer's patches

66

What do Peyer's patches specialize in?

Making helper T cells that tell B cells to make IgA and making helper T cells make a Th2 cytokine profile

67

Th2 bias is preferable in what location of the body?

Gut

68

What interleukins are associated with the Th2 cytokine bias?

IL-4, IL-5, and IL-13

69

What governs the traveling of T cells?

Adhesion molecules

70

Do adhesion molecules allow more freedom for travel for naive or experienced T cells?

Naive

71

Why would it be detrimental to enable experienced T cells to have more travel room?

Possibility for self damage (autoimmune)

72

When T cells previously used in the gut are reactivated, where are they likely to go?

Back to the gut (where they were originally activated) due to their restricted travel by adhesion molecules

73

Where do experienced B cells tend to settle down?

In bone marrow and spleen to make antibodies

74

Where can can specialized populations of lymphocytes be found besides lymphoid tissue?

Liver, lamina propria of the gut, base of the epithelial lining of the gut, reproductive epithelia

75

What seems to be the important role of lymphocyte populations outside of the lymphoid tissue?

Protection from infection