immunology
the study of molecules, cells, organs, and systems responsible for the recognition and disposal of nonself materials and how they work, or can be manipulated; all aspects of body defense, such as antigens and antibodies, allergy, and hypersensitivity, are
nonself
recognition of foreign material in body defenses; antigenically dissimilar from self
immunoglobulin
protein produced by the immune system, synonym for antibody; divided into five classes: IgM, IgG, IgD, IgA, and IgE (IgG is the most abundant)
hematopoietic cells
blood-producing cells
autoimmune disorder
a disorder that results from the immune system attacking the body's own tissue because of failure to recognize self
innate resistance
natural or inborn ability to resist infection
inflammation
tissue reaction to injury caused by physical or chemical agents, including microorganisms; symptoms include redness, tenderness, pain, and swelling
phagocytosis
form of endocytosis; important body defense mechanism involving the process whereby specialized cells engulf and destroy foreign particles, such as microorganisms or damaged cells; macrophages and segmented neutrophils (PMNs) are the most important phagoc
complement
a group of soluble blood proteins (enzymes) consisting of C1 to C9; present in the blood and can produce inflammatory effects and lysis of cells when activated
antigen
a foreign substance (immunogen) that can stimulate the production of antibodies (immune response)
acquired immunity
augmentation of body defense mechanisms in response to a specific stimulus, which can cause the elimination of microorganisms and recovery from disease; response frequently leaves the host with a specific memory (acquired resistance), which enables the bo
humoral-mediated immunity
form of body defense against foreign substances represented by antibodies and other soluble extracellular factors in the blood and lymphatic fluid
antibodies
specific glycoproteins (immunoglobulins) produced in response to an antigenic challenge; can be found in blood plasma and body fluids; have a wide range of specificities for different antigens and can bind to and neutralize bacterial toxins or bind to the
active immunity
form of immunity produced by the body in response to stimulation by a disease-causing organism (naturally acquired active immunity) or by a vaccine (artificially acquired active immunity
vaccination
a method of stimulating the adaptive immune response and generating memory and acquired resistance without contracting disease; a form of artificial, active-acquired immunity
immunocompetent
the ability to mount an immune response; host is able to recognize a foreign antigen and produce specific antigen-directed antibodies; term refers to lymphocytes that acquire thymus-dependent characteristics, which allow them to function in an immune resp
passive immunity
temporary immune protection resulting from the transfer of antibodies from another individual who has actively formed antibodies; i.e. transfer from mother to unborn child; can also be a transfer of lymphocytes from another individual known to be immune t
cell-mediated immunity
the type of immunity dependent on the link between T cells and macrophages
major histocompatibility complex (MHC)
a genetic region in human beings and other mammals responsible for signaling between lymphocytes and antigen-bearing cells;also the major determinant of transplant compatibility (or rejective)
allografts
graft of tissue from a genetically different member of the same species
mononuclear phagocyte system (MPS)
the body defense system composed of macrophages and a network of specialized cells of the spleen, thymus, and other lymphoid tissues; formerly called the reticuloendothelial system (RES)
cytokines
polypeptide product of activated cells (lymphocytes or macrophages) that controls a variety of cellular responses and thereby regulates the immune system
interleukins
cytokine or chemical messenger produced by leukocytes that affect the inflammatory process through an increase in soluble factors or cells
innate immune system
natural or inborn resistance to infection after microorganisms have penetrated the first line of resistance; innate immunity
adaptive immune system
organized around T and B lymphocytes
genome
the complete DNA composition (hereditary factors)
pathogen-associated molecular patterns (PAMPs)
antigens on a few large groups of microorganisms
pattern recognition receptors (PRRs)
receptors of the innate immune system that recognize PAMPs
endogenous
originating or produced within an organism, tissue, or cell
exogenous
pertaining to a source outside of a cell or system