Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
17 Cards in this Set
- Front
- Back
|
Hematopoietic stem cells and immune system |
Precursors for the cells of the immune system Differentiates into bone marrow, nerve cells, heart muscle cells, pancreatic cells HSC splits off into myeloid and lymphoid lineages |
|
|
Phagocytic/endocytic barriers |
Various cells internalize (endocytose) and break down foreign macromolecules Specialized cells (blood monocytes, neutrophils, tissue macrophages) internalize (phagocytose), kill, and digest whole microorganisms Mainly consists of macrophages and neutrophils |
|
|
Phagocytized bacteria trigger |
macrophages to release cytokines; causes inflammatory response Vasodilation and increased vascular permeability cause redness, heat, swelling and pain Inflammatory cells migrate into infected tissue, releasing more inflammatory mediators |
|
|
Lymphocyte extravasation |
The movement of leukocytes out of the circulatory system, towards the site of tissue damage or infection |
|
|
Local acute inflammatory response |
Migration of immune cells into tissue lead to a local acute inflammatory response Release of cytokines from macrophages leads to stimulation of other immune cells Factors released from other immune cells further activate macrophage |
|
|
Dendritic cells |
Also phagocytic; but main function is as an antigen presenting cell Bridge between nonspecific (innate) and specific (adaptive) immune responses Carries information about the type of inflammation to other cells to initiate response --> Presents bacterial antigens to naïve T-cells Dendritic cells are the key to initiating adaptive immune response Activated dendritic cells travel to lymph node and present antigen to T cells Naïve T cells mature into activated T cells |
|
|
Toll-like Receptors (TLR) |
Link between innate and adaptive immune response Allows dendritic cells to recognize pathogen |
|
|
There are two major pathways to detect pathogens inside the cell |
Endosomal pathways Cytosolic pathways |
|
|
Endosomal pathways |
Pathogens are recognized by TLR3, TLR6, TLR7, TLR9 Leads to activation of NF-kappa beta Activates proinflammatory cytokines |
|
|
Cytosolic pathways |
Leads to Inflammasome activation/formation Leads to production of two cytokines IL-1β IL-18 |
|
|
Adaptive immune system made up of two components |
Humoral & Cell-mediated |
|
|
Humoral mediated |
B-cell associated B cells produce antibodies (immunoglobulins) |
|
|
Cell-mediated |
Response = T-cell (2 kinds) associated T-helper cells T-cytotoxic cells |
|
|
B-cell receptor |
B-cell receptor is really the Immunoglobulin bound to the surface of the B cell Surface immunoglobulin antigen-binding site = region that recognizes pathogen Antigen binding site also known as variable region of the Ig Surface immunoglobulin also has a transmembrane region When surface Immunoglobulin (Ig) secreted → referred to as an antibody Immunoglobulin/Antibody made of 2 heavy chains and 2 light chains Heavy chain region near membrane is also referred to as the constant region |
|
|
T-cell receptor |
Comprised of an α-chain and a β-chainT cell receptor also has an antigen binding site to recognize pathogenAntigen binding site = variable region T cell receptor also has a constant and transmembrane regionUnlike immunoglobulins, T-cell receptors are never secreted (always bound) |
|
|
There are five major types (isotypes) of antibodies |
The 5 isotypes have differently structured constant regions but similar variable regions Difference in constant region allows isotypes to function differently IgG (can cross placenta) IgD IgE (important in allergic reactions/parasitic invasion) IgA A dimer abundant in mucosal secretions Prevents passage of foreign substances into the circulatory system IgM (pentamer) Efficient complement fixing Expressed on the surface of B cells The five immunoglobulins are joined by a “J-chain” Immunoglobulin expressed in the B-cell receptor is always of the IgM isotype |
|
|
First response sensitizes mast cell |
After first exposure, allergen bypasses previous steps and binds directly to antigen site on sensitized mast cell → brings two Ig molecules together Leads to activation of the mast cells Degranulation of mast cells leads to release of vasoactive amines Vasoactive amines induces changes causing allergy reaction |
