Term
| what are the primary lymphoid organs? what happens in it? |
|
Definition
| the thymus and bone marrow, where lymphocytes are actually generated. this is where selection processes take place, self-reactive lymphocytes should be eliminated and in the thymus, every cell is checked for compatibility with MHC. naive lymphocytes are found here, (have not seen antigen). |
|
|
Term
| what are secondary lymphoid organs? what happens here? |
|
Definition
| tonsils, adenoids, spleen, (blood filter), lymph nodes, (drain almost every area of the body), and mucosal surfaces, (GI, RT). this is where the work occurs, and where all lymphocytes are found |
|
|
Term
| what is a normal size for lymph nodes except in the inguinal area? |
|
Definition
|
|
Term
| what do secondary lymphoid organs do in terms of antigen? |
|
Definition
| dendritic cells bring antigen to secondary lymph organs from common portals of entry, (RT, GI,skin), where it is concentrated, processed and presented to T lymphocytes |
|
|
Term
| what do naive lymphocytes do? |
|
Definition
| naive lymphocytes migrate through the peripheral organs and initiate responses upon antigen encounter |
|
|
Term
| what does the anatomy of secondary lymphoid organs promote? what do they generate? |
|
Definition
| cellular interactions required for the activation phase of adaptive immune response. secondary lymphoid organs generate memory and effector cell populations that migrate the periphery |
|
|
Term
| what does the anatomy of secondary lymphoid organs promote? what do they generate? |
|
Definition
| cellular interactions required for the activation phase of adaptive immune response. secondary lymphoid organs generate memory and effector cell populations that migrate the periphery |
|
|
Term
| what is the difference between humoral and cell mediated immune response? |
|
Definition
| humoral immune responses by definition include the production of antibody, (antibodies are dealt with by B lymphocytes, but T cells can help, leading to neutralization/opsonization). cell mediated immunity typically is induced by intracellular infection, (chlamydia or viruses), and requires T cells, (which require APCs like dendritic cells), that then produce cytokines, leading to proliferation of macrophages, cytotoxic T cells, etc, and enhance the cytotoxicity of these cells via INF-gamma |
|
|
Term
|
Definition
|
|
Term
| what are the three major subsets of B cells? |
|
Definition
| marginal zone B cells, follicular B cells, and B-1 B cells |
|
|
Term
| what are marginal zone B cells? |
|
Definition
| marginal zone B cells respond to blood borne polysaccharide antigens, (T cells are not involved here, b/c they only see protein) |
|
|
Term
| what are follicular B cells? |
|
Definition
| these make up the majority of B cells, make bulk of T dependent, class switched high affinity antibody responses to protein antigens. they also give rise to plasma cells. |
|
|
Term
|
Definition
| these are important in making antibodies to non protein antigens at mucosal site and in the peritoneum. typically not found in lymph nodes. |
|
|
Term
| what are T-lymphocytes centrally important to? where are they derived from? |
|
Definition
| adaptive antigen-specific immune responses. they are derived from the Thymus gland. |
|
|
Term
| what are the 2 major types of T cells? |
|
Definition
|
|
Term
|
Definition
| most are helper/inducer, some are Tregs that make cytokines, some regulate afferent, (generation), and efferent, (effecting the response), arms of many types of response, via production of antibody, generation of cell mediated immune response. there are usally 2x more CD4+ than CD8+. |
|
|
Term
| what do CD8+ cytolytic T cells do? |
|
Definition
| these T cells are cytoxic or cytolytic for cells bearing the relevant antigen, and may also regulate the immune response |
|
|
Term
| what is the molecular basis for antigen specificity in B lymphocytes? |
|
Definition
| the receptor structures on lymphocytes. |
|
|
Term
| what gives T cell receptors/B cell surface immunoglobulins their overall structure and functionality? |
|
Definition
|
|
Term
| what is the difference between T-cell receptors and B cell surface immunoglobins? |
|
Definition
| T cell receptors are not 4 light+heavy peptide chains, they only have 2, (alpha+beta chains) |
|
|
Term
| are both T cell and B cell receptors members of the immunoglobin superfamily? |
|
Definition
|
|
Term
| what is the structure of B lymphocyte surface immunoglobulins? |
|
Definition
| the B lymphocyte surface immunoglobulin has 2 variable region, (antigen-binding site), on its 2 light+heavy chain pairs allowing for a high degree of specificity |
|
|
Term
| what do most CD4+ and CD8+ T cells have? |
|
Definition
| an alpha/beta chain TCR, (T cell receptor) |
|
|
Term
| what 2 things does the antigen specific end of T cell receptors recognize? |
|
Definition
| the foreign protein as well as the polymorphic residue of the MHC. the foreign protein is actually anchored in a pocket of the MHC. |
|
|
Term
| how many T cells have gamma/delta T cell receptors? what role do they play? |
|
Definition
| only a minority of T cells have gamma/delta T cell receptors. they have a limited diversity in antigen specificity, however they recognize non-peptide antigens w/out processing and presentation via MHC. they may be an important first line of defense in the skin and gut. |
|
|
Term
| what are the three kinds of specific immunity? |
|
Definition
| active, passive, adoptive |
|
|
Term
| what are the two kinds of active, (self-made), specific immunity? |
|
Definition
| natural, via infection or artificial via vaccination |
|
|
Term
| what are the two kinds of passive, (aquired), specific immunity? |
|
Definition
| natural, via transplacental/colostral antibody transfer, or artificial, via administration of immune globulins |
|
|
Term
| what is adoptive specific immunity? |
|
Definition
| transfer of immune cells, doesn't really work in humans due to differences in immune systems |
|
|
Term
| what are the cardinal features of an adaptive immune response? |
|
Definition
| specificity, diversity, adaptibility, memory, clonal explansion, specialization, self-limitation, discrimination of self |
|
|
Term
| how does specificity play a role as a cardinal feature of the adaptive immune response? what is it a function of? |
|
Definition
| an adaptive immune response must be specific for distinct antigens, which is a function of distinct antigen receptors on the lymphocyte surface, (which should be present before exposure to antigen). specificity is the basis of clonal selection theory. |
|
|
Term
| how does diversity play a role as a cardinal feature of the adaptive immune response? |
|
Definition
| the total number of antigenic specificities of lymphocytes in an individual is large, (at least 1,000,000,000 different antigens), resulting in incredible antigen receptor variablility among lymphocytes. |
|
|
Term
| how does adaptibility play a role as a cardinal feature of the adaptive immune response? |
|
Definition
| the immune system needs to have the ability to respond to antigens not previously found in nature. |
|
|
Term
| how does memory play a role as a cardinal feature of the adaptive immune response? |
|
Definition
| the exposure of antigens to the immune system enhances its ability to respond again, and upon secondary infection, the response is faster, bigger, and qualitatively different |
|
|
Term
| how does clonal expansion play a role as a cardinal feature of the adaptive immune response? |
|
Definition
| clonal expansion increases the number of antigen-specific lymphocytes to keep pace with microbes during an infection, these clones are thus specific for the particular pathogen. this is why lymph nodes enlarge. |
|
|
Term
| how does self limitation play a role as a cardinal feature of the adaptive immune response? |
|
Definition
| the immune response should wane with time in proportion to antigen elimination. effector cells are thus short lived. |
|
|
Term
| does discrimination of self/non-self play a role as a cardinal feature of the adaptive immune response? |
|
Definition
|
|
Term
| what is clonal selection theory? (4 main points -> will def be on test) |
|
Definition
1) every individual contains numerous clonally derived lymphocytes
2)each lymphocyte has an antigen receptor specific for a single antigen, (all antigens on a lymphocyte are identical; one lymphocyte -> one specificity)
3)antigen receptors are present prior to antigen exposure
4)the antigen selects a pre-existing clone and activates it, (the receptor is there prior to contact) |
|
|
Term
| what are the major cells involved with innate immunity? |
|
Definition
|
|
Term
| what are the major cells involved with aquired immunity? |
|
Definition
| B+T lymphocytes, (though dendritic cells, macrophages, and monocytes play a critical role in developing aquired immunity) |
|
|
