L19: Functional Lymphoid Anatomy

Question 1

What’s the learning goal?

Answer 1

You will understand the role of the central and peripheral lymphoid tissues in generating and maintaining the adaptive immune system.

Question 2

Central lymphoid tissues (name 2)

Answer 2

1. bone marrow
2. thymus

Question 3

Peripheral lymphoid tissue (name 4)

Answer 3

1. lymph
2. node
3. spleen
4. MALT

Question 4

Unlike T-cells which migrate from bone marrow to thymus for development, B-cells

Answer 4

stay put and mature in the bone marrow

Question 5

What cells are critical for B-cell development in bone marrow

Answer 5

stromal cells in bone marrow

Question 6

Each lymphocyte recognizes

Answer 6

only 1 type of antigen, & if it proliferates, all subsequent lymphocytes will be a clone of the first one.

Question 7

Adaptive immunity occurs if

Answer 7

the lymphocyte meets its corresponding antigen in the peripheral lymphoid tissue.

Question 8

lymphocytes and lymph return to blood via

Answer 8

thoracic duct

Question 9

The final stages of development of immature B cells into mature B cells occur in

Answer 9

the peripheral lymphoid organs

Question 10

Early stem cells reside in the ________ just below the inner cavity of the long bones, but then move toward ________ cells in the trabeculae

Answer 10

Endosteum, stromal

Question 11

What maturation factors do stromal cells secrete, that promote B-cell development in the trabeculae?

Answer 11

1. FLT3
2. IL7
3. SCF
4. CXCL12

Question 12

Central Tolerance: immature B cells in the BM are tested for

Answer 12

reactivity to self antigens, or autoreactivity, and are eliminated if autoreactive.

Question 13

4 possible fates of B-cells, during central tolerance screening?

Answer 13

1. No self-reaction - migrates to periphery
2. Multivalent self-molecule - apoptosis or receptor editing
3. Cross-linking receptors to soluble self-molecule: anergy
4. Low-affinity, non-cross linking: clonal ignorant (may cause auto-immunity)

Question 14

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