AP Biology Chapter 43: The Body's Defenses Flashcards

cells
Terms Definitions
innate immunity
present before any exposure to pathogens and is effective from the time of birth
acquired immunity
develops only after exposure to inducing agents such as microbes, abnormal body cells, toxis, or other foriegn substances
bone marrow
B Cells are made in the _____ _____.
thymus
T cells are made in the ________.
lymphocyte
type of white blood cell that mediates acquired immunity
antibody
a protien secreted by plasma cells that binds to a particular antigen and marks it for elimination; also called immunoglobulin
lysozyme
an enzyme in sweat, tears, and saliva that attacks bacterial cell walls
phagocytosis
the ingestion of invading microorganisms by certain types of white blood cells generically referred to as phagocytes
neutrophil
the most abundant white blood cell, phagocytic and tend to self-destruct as they destroy foreign invades, limiting life span to a few days
monocyte
a type of white blood cell that migrates into tissues and develops into a macrophage
eosinophil
a type of white blood cell with low phagocytic activity that is thought to play a role in defense against parasitice worms by releasing enzymes toxic to these invaders
dendritic cell
an antigen--presenting cell, mainly in lymphatic tissues and skin that is effecient in presenting antigens o naive helper T cells, initiating a primary immune response
complement system
group of 30 blood proteins that may amplify the inflammatory response
interferon
alpha and beta, provide innate defence against viral infections, has antiviral or immune regulatory functions
inflammatory response
damage to tissue by a physical injury or the entry of pathogens leads to release of numerous chemical signals that trigger inflammation
histamine
active chemical triggers dilation and increased permeability of neraby capillaries
mast cells
These cells store histamine
chemokine
about 50 protiends that help direct migration of white blood cells to an injury site and induces other changes central to inflamation
natural killer cell
type of white blood cell that can kill tumor cells and virus--infected cells;an important component of innate immunity
antigen
any foreign molecule that is specifically recognized by lymphocytes an elicites a response
epitope
an antigenic determinate
antigen receptor
the general term for a surface protein, located on B cells and T cells, that bind to antigens, initiating aquired immune responses
T cell receptor
consists of two different polypeptide chains an alpha and beta chain linked by a disulfide bridge
major histocompatibility complex
MHC molevules are so named because they are encoded by a family of genes
antigen presentation
the process by which an MHC molecules binds to a fragment of an intracellular protein antigen and carries it to the cell surface, whre it is displayed and can be recognized be a T cell
class 1 MHC
found on almost all nucleated cells of the body, bind peptides derived from foreign antigens that have been synthesized within a cell
class 2 MHC
made by just a few cells, mainly dendritic cells, macrohpages and B cells
clonal selection
when a mature lymphocyte encounters and binds a specific antigen, leading to its activation, proliferation and differentiation
effector cell
a muscle cell or gland cell that performs the body's responses tp stimuli; responds to signals from the brain or other processing center of the nervous system
memory cells
long-lived cells bearing receptors specific for the same inducing antigen
primary immune response
the selective poliferation and differentiation of lymphocytes that occurs the first time the body is exposed to a particular antigen
plasma cell
the antibody--secreting effector cell of humoral immunity;arises from antigen-stimulated B cells
secondary immune response
if an individual is exposed again to the same antigen, the response is faster
humoral immune response
involves the activation and clonal selection of B cells, resulting in production of secreted anti-bodies that circulate in the blood and lymph
cell mediated immune response
involves the activation and clonal selection of cytotoxic T cells, which directly destory certain target cells
helper t cell
type of T cell when activated, secretes cytokines that promote the response of B cells and cytotonic T cells to antigens
CD4
surface protein, present on most helper T cells, that binds o class 2 MHS molecules on antigen-presenting cells, enhancing the interaction between the T cell and antigen-presenting cell
CD8
surface protein present on most cytotoxic I cells, greatly enhances the interaction between a target cell and cytotoxic T cell
polyclonal
procuts of many different clonges of B cells
monoclonal
they are prepared from a single clone of B cells grown in culture
membrane attack complex
a molecular complex consiting of a set of complement proteins that forms a pore in the membrane of bacterial and transplanted cells, causing the cells to die by lysis
active immunity
can develop as a result of natural infection of immunization
passive immunity
immunity can also be conferred by transferring antibodies from an individual who is immune to a particular infectious agent to somone who is not
rh factor
protein antigen on the suface of red blood cells that dictate wether the blood is positive or negative
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