L19: Functional Lymphoid Anatomy Flashcards Preview

Host Defense Exam 2 (by Richie) > L19: Functional Lymphoid Anatomy > Flashcards

Flashcards in L19: Functional Lymphoid Anatomy Deck (14):
1

What's the learning goal?

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

2

Central lymphoid tissues (name 2)

  1. bone marrow
  2. thymus

3

Peripheral lymphoid tissue (name 4)

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

4

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

stay put and mature in the bone marrow

5

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

stromal cells in bone marrow

6

Each lymphocyte recognizes

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

7

Adaptive immunity occurs if

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

8

lymphocytes and lymph return to blood via

thoracic duct

9

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

the peripheral lymphoid organs

10

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

Endosteum, stromal

11

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

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

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12

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

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

13

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

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)

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