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58 Cards in this Set
- Front
- Back
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What are white blood cells called and what do they include?
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leukocytes.
include: neutrophils, basophils, eosinophils (polymorphonuclear granulocytes), monocytes, lymphocytes |
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Unlike erythrocytes, what do leukocytes use the blood mainly for?
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transportation.
They leave the circulatory system to enter tissues where they function. |
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What are plasma cells?
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B lymphocytes
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Where are plasma cells primarily found?
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In the tissues where they differentiate from their parent lymphocytes.
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What is the main function of plasma cells?
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to synthesize and secrete antibodies
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What are macrophages derived from?
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monocytes that pass through the walls of blood vessels and enter the tissues (become macrophages)
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what is the major function of macrophages?
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engulfing particles and microbes by endocytosis
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where are macrophages strategically placed?
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in places where they will encounter their targets
e.g. skin, internal surfaces of respiratory and digestive system tubes |
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what are macrophage-like / dendritic cells?
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cell populations that are not macrophages and are not descended from monocytes but exert various macrophage functions
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Where are macrophage-like/dendritic cells found?
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scattered in almost all tissues
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What are mast cells?
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bone marrow cells that have entered the blood and then left te blood vessels to enter connective tissue, where they differentiate and undergo cell division.
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Where are mast cells found?
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throughout connective tissues, particularly beneath the epithelial surfaces of the body.
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What is the main difference between mast cells and basophils?
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Mast cells are not normally found in the blood
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What is the most striking anatomical feature of mast cells?
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Their very large number of cytosolic vesicles, which secrete locally acting chemical messeengers such as histamine
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What os the overall function of lymphocytes?
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They serve as RECOGNITION cells in specific immune defenes and are essential for ALL aspects of these responses
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What are the two most important abilities of neutrophils, monocytes, macrophages, and dendritic cells?
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Their ability to secrete inflammatory mediators and to function as phagocytes
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What does a phagocytic cell do?
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engulfs and usually destroys particulate matter.
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What are cytokines?
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protein messengers that regulate host cell division and function in both nonspecific and specific immune defences.
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What do cytokines do?
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They link the components of the immune system together. Communication system (cross-talk)
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What is cross-talk essential for?
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the precise timing of the functions of the immune system
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What noninnumological processes are cytokines also involved in?
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bone formation and uterine function
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What are the 2 main functions of neutrophils, and where are they produced?
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1. Phagocytosis
2. Release chemicals involved in inflamation (vasodilators, chemotaxins, etc) produced in the bone marrow |
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What are the main functions of basophils and where are they produced?
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carry out functions in blood similar to those of mast cells in tissues
produced in the bone marrow |
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What do nonspecific immune defences do?
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They protect against foreign cells or matter without having to recognize their specific identities
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What is the nonspecific defense system based on that distinguishes it from the specific defense system?
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The system is based on carbohydrates and lipids for detecting the presence of foreign cells
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What are the nonspecific immune defences made up of?
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defences at the body surfaces (first line of defence--barriers offered by surfaces exposed to the external environment), response to injury (inflammation), and a family of antiviral proteins called interferons.
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What is inflammation?
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The local response to infection or injury.
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What are the functions of inflammation?
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To destroy or inactivate foreign invaders and to set the stage for tissue repair.
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What are the key mediators of inflammation?
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The cells that function as phagocytes.
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What are the main functions of eosinophils and where are they produced?
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1. to destroy multicellular parasites
2. to participate in immediate hypersensitivity reactions produced in the bone marrow |
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What are the main functions of monocytes and where are they produced?
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1. carry out functions in lood similar to those of macrophages in tissues
2. Enter tissues and transform into macrophages produced in the bone marrow |
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What are the main functions of lymphocytes and where are they produced?
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Lymphocytes serve as recognition cells in specific immune responses and are essential for all aspects of these responses
B cells and NK cells mature in the bone marrow, T cells mature in the thymus. They are activated in peripheral lymphoid organs |
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What are the functions of B cells?
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1. Initiate antibody-mediated immune responses b y binding specific antigens to the B cell's plasma membrane receptors, which are immunoglobins
2. During activation, they are transformed into plasma cells, which secrete antibodies 3. Present antigen to helper-T cells |
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What is the function of Cytotoxic T cells (CD8 cells)?
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to bind to antigens on plasma membrane of target cells (virus infected cells, cancer cells, and tissue transplants) and directly destroy the cells
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What is the function of Helper T cells (CD4 cells)?
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To secrete cytokines that help activate B cells, cytotoxic T cells, NK cells, and macrophages
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What are the functions of NK cells?
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1. Bind directly and nonspecifically to virus-infected cells and cancer cells and kill them.
2. Function as killer cells in antivody-dependent cellular cytotoxicity (ADCC). |
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What do plasma cells do and where are they produced?
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they secrete antibodies
produced in the peripheral lymphoid organs; they differentiate from B cells during immune responses. |
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What are the 4 functions of macrophages, and where are they produced?
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1. phagocytosis
2. extracellular killing via secretion of toxic chemicals 3. process and present antigens to helper T cells 4. secrete cytokines involved in inflammation, activation, and differentiation of helper T cells, and systemic responses to infection or injury (the acute phase response) |
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What are the functions of dendritic (macrophage-like) cells and where are they produced?
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functions - same as macrophages
produced in almost all tissues and organs, and microglia in the central nervous system |
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What is the function of mast cells and where are they produced?
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release histamine and other chemicals involved in inflammation
produced in the bone marrow, and reside in almost all tissues and organs. they differentiate from bone marrow cells |
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In the sequence of events in a nonspecific local inflammatory response to bacteria, what does entry of bacteria into tissues cause?
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Injury to tissues which causes the release of chemicals to initiate specific events.
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What is the first event that is initiated in a nonspecific local inflammatory response after the relase of chemicals from injury to tissues?
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-Vasodialation of the microcirculation in the infected area, which leads to increased blood flow
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In the nonspecific inflammatory response, what event is initiated after vasodialation?
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Large increase in protein permeability of the capillaries and venules in the infected area, with resulting diffusion of protein and filtration of fluid into the intersitital fluid.
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In the nonspecific inflammatory response, what event is initiated after the increase in protein permeability?
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Chemotaxis occurs: movement of leukocytes from the venules into the interstitial fluid of the infected area.
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In the nonspecific inflammatory response, what event is initiated after chemotaxis?
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Destruction of bacteria in the tissue either through phagocytosis or by other mechanisms
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In the nonspecific inflammatory response, what event is initiated after phagocytosis/destruction of bacteria?
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Tissue repair. The end.
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What are the familiar signs of tissue injury and inflammation?
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local redness, swelling, heat, and pain
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What are some of the local inflammatory mediators?
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kinins, complements, products of blood clotting, histamines, eicosanoids, platelet-activating factors, cytokines and chemokines, lysosomal enzymes, nitric oxide, and other oxygen-derived substances
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What are some cytokines?
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Interleukin 1, tumor necrosis factor, interleukin 6, interleukin 2, interferons, interferon-gamma, chemokines, and colony stimulating factors
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What are the two general categories that mediators fall into?
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1. peptides (ex kinins) generated in the infected area by enzymatic actions on proteins that circulate in the plasma
2. substances secreted into the extracellular fluid from cells that either already exist in the infected area (ex injured cells or mast cells) or enter it during inflammation (ex neutrophils) |
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What does vasodialation and increased permeability to protein do?
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increases blood flow to the inflamed area (which accounts for the redness and heat) which increases the delivery of proteins and leukocytes.
Also increases permeability to the protein which ensures that plasma proteins that participate in inflammation (often normally restrained by the intact endothelium) can gain entry to the interstitial fluid. |
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What is a side effect of vasodialation and increased permeability to protein?
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Net filtration of plasma into the interstitial fluid and the development of edema (swelling). This accounts for the swelling in an inflamed area, which has no real adaptive value.
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What is chemotaxis?
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The multistage process of circulating neutrophils moving out of the blood across the endothelium.
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What are the nonspecific mechanisms of immunity (innate immunity)?
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-Disease resistant mechanims not specific to a particular pathogen.
-the first line of defence to handle the critical period immediately after host exposure to a pathogen |
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What are the specific mechanisms of immunity (adaptive immunity)?
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-High degree of specificity as well as memory
-requires more time to develop because "programming" something |
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what is the first line of defence?
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the skin, mucous membranes, and secretions of skin and mucous membranes. there are antibodies in sweat and antibodies and antimicrobials in tears, nasal, vaginal, and other secretions
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What is the second line of defence?
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phagocytic white blood cells
antimicrobial proteins the inflammatory response |
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What is the third line of defence?
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lymphocytes and antibodies (specific defence system - adaptive)
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