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9 Cards in this Set
- Front
- Back
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name the primary and secondary lymphoid organs (LO #3)
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Primary = thymus (T cells) and bone marrow (B cells)
Secondary: lymph nodes, spleen, mucosal lymphoid tissues (like adenoids, tonsils, GALT) development in primary sites DOES NOT DEPEND ON ANTIGENS - in fact, the area must be antigen free. |
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talk about what natural killer cells do and their specific receptors.
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NO SPECIFIC RECEPTOR on NK cells.
They go around engulfing cells. If it's cancerous, they kill it. If it's infected, they kill it. If not, they detatch and move on. Called immunosurveylance. Considered part of the innate immunity. |
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talk about dendritic cells:
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these migrate to secondary tissues and their main job is to present antigens, in the context of MHC (or HLA in people), to the T-CELLS.
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what do macrophages do?
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interact with T-cells. They produce IL-12, to activate T- cells, which in turn produce IFN-gamma, which activate macrophages.
Also, they present antigens to t-cells, with MHC. Note that these antigens come from the phagolysosome. they're activated also by exogenous proteins like LPS. |
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neutrophils?
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most abundant cell in the blood. all about acute inflammation. Can kill by phagocytosis or by excreting poisons.
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what do eosinophils do that's nifty?
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they have binding sites for IgE. Important in allergic reactions and parasites.
Especially - Helminths! Eosinophils have binding sites for IgE's made specifically against the helminths. The eosinophil can now bind all over the worm and all inject in poisons togeter to kill it. Called antibody-dependent cytotoxcitity (ADCC). |
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how do lymphocytes get into lymph nodes? how are they activated?
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through the arterial system 0 most specifically, transporting through high endothelial venules (HEV's).
They're activated by binding to their antigen that fits their individual receptor. T-cells will then leave to go to the site of infection. |
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what do lymph nodes look like and where do the B and T cells live? what happens? what about spleen?
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B cells are in the cortex, T cells in the paracortex.
lymph nodes are essentially antigen collection spots, collecting from the LYMPH, SKIN, and RESPIRATORY TRACT. Dendridic cells come in through the lymphativ vessels with antigens to present, along with MHC. These will go to the T-cells. Note that plasma cells go to the medulla to secrete antibodies. The Spleen is a BLOOD FILTER and collects antigen from the BLOOD - it's NOT connected to the lymph. Red pulp is for collecting blood stuff, White is immunologic. T cells are packed around the PALS (periarteriolar sheath, central areteriol) while the B cells are in primary and secondary follicles. |
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what's going on in GALT?
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gut associated lymphoid tissue has an M cell at the top, though which antigens can pass. Pinocytosed.
Then they immediately encounter dendridic cells which can carry them away to the lymph nodes and spleen for presentation. note also that IgA gets secreted up through the peyer's patches back up into the gut to kill whatever got presented through the M cell. |
