Term
| List 3 primary lymphoid organs: |
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Definition
1. Thymus
2. Bone Marrow in mammals
3. Bursa of Fabricius in birds |
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Term
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Definition
| Located in the cranial mediastinum and it's most active early in life and reaches maximum development at puberty |
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Term
| What is the Bursa of Fabricius in Birds? |
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Definition
| It's the outgrowth of cloaca |
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Term
| List a few secondary lymphoid organs: |
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Definition
1. Lymph Nodes (mostly lymphocytes)
2. Spleen (many lymphocytes)
3. Lymphocytes
4. Peyer's Patches |
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Term
Explain the process of Derivation of cells of the immune system: |
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Definition
1. Primitive hematopoietic stems cells in bone marrow give rise to lymphoid cells and erythromyeloid cells
2. Lymphoid cells give rise to B and T Lymphocytes
3. B lymphocytes mature into plasma cells which produce antibodies (immunoglobulins)
4. T Lymphocytes mediate cell-mediated immune reactions |
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Term
| What do T lymphocytes do with cell-mediated immune reactions? |
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Definition
| Lyse cells/ phagocytize/ produce substances that direct cell functions |
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Term
| What are erythromyeloid cells? |
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Definition
They are all other hematopoietic cells besides lymphtocytes.
EXAMPLES: Erythrocytes, megakaryocytes, neutrophils, monocytes, eosinophils |
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Term
| Where are lympthocytes derived? |
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Definition
| Derived from bone marrow prelymphoid stem cells and give rise to B and T lymphocytes |
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Term
| Where are T-lymphocytes located? |
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Definition
Thymus gland--migrate there during embryo fetal stage of development
Are named T-Lymphocytes because they are found in the "T"hymus |
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Term
| Where are B-lymphocytes located? |
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Definition
Bone marrow
Called B-lymphocytes because they are found in "B"one Marrow |
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Term
| After leaving their primary organs, where do T and B lymphocytes head? |
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Definition
| They colonize in secondary lymphoid organs such as the lymph nodes, spleen, etc. |
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Term
| How can you compare T and B lymphocyte morphology? |
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Definition
| Cannot be distinguished by light or electron microscope but you can test to identify certain molecules on their cell membranes |
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Term
| What fraction of all circulating lymphocytes are T-lymphocytes? |
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Definition
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Term
| What are 4 subsets of T-lymphocytes? |
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Definition
1. T-Helper cells
2. T-Cytotoxic Cells
3. T-memory Cells
4. Natural Killer Cells |
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Term
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Definition
They divide rapidly and secrete small proteins called cytokins that regulate or assist in the immune response
In normal human blood, there are about twice as many T-helper cells as T-cytotoxic cells |
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Term
| What are T-cytotoxic Cells? |
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Definition
| They are cells involved in mediating the killing of virus infected or tumor cells which are recognized by the body as foreign. |
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Term
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Definition
They are cells that inactive clones of Ag-sensitized T-Cells and persist long term after an infeciton has resolved.
They multiply upon re-exposure to their antigen and help to speed up the immune response the next time the Ag is encountered by the body. |
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Term
| What are natural Killer cells? |
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Definition
They are T-cells that do not recognize specific Ag and do not require previous sensitization.
Account for 10-15% of peripheral lymphocytes and are a part of innate immunity |
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Term
| What do B-lymphocytes differentiate into? |
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Definition
| Into plasma cells that produce immunoglobulins |
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Term
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Definition
| Descendants of B Lymphocytes that are oval shape, with an eccentrically located round nucleus and basophilic cytoplasma due to the presence of many ribosomes and lots of Rough Endoplasma reticulum |
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Term
| What are Rough Endoplasmic Reticulum? |
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Definition
| Site of synthesis of immunoglobulins and is the primary secretory product of plasma cells |
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