chapter 45 ~immue system Flashcards
A constellation of disorders that follows infection by the human immunodeficiency virus (HIV).
Acquired immunodeficiency syndrome (AIDS)
A retrovirus that causes acquired immunodeficiency syndrome (AIDS)
Human immunodeficiency virus (HIV)
The process of administrating a weakened form of a disease to patients as a means of giving them immunity to a more serious form of the disease
Vaccination
The body’s organ system for defense against pathogens or abnormal cells.
Immune system
Nonspecific defenses against pathogens that include anatomical barriers, inflammation, and the complement system. The system blocks, inhibits, or kills many pathogens, but retains no memory of the encounters. The innate system is found in all animals. It is one of two components of the immune system in vertebrates.
Innate immune system
The mechanisms that target foreign molecules in a specific way to remove them from the body. The adaptive immune system is one of two components of the immune system in vertebrates. It is not found in invertebrates.
Adaptive immune system
The defensive reactions of the immune system.
Immune response
The initial response by the body to eliminate cellular pathogens and prevent infections that involves mechanisms of the innate immune system. Innate immunity is always ready to combat pathogens, mounting an immediate, nonspecific response against any invading pathogen but having no memory of prior exposure to the pathogen.
Innate Immunity
In innate immunity, antimicrobial peptides that protect the epithelial surfaces against invading pathogens.
Defensins
A type of phagocytic leukocyte (white blood cell) that engulfs pathogens and tissue debris in damaged tissues.
Neutrophils
A white blood cell. Together, the various types of leukocytes eliminate dead and dying cells from the body, remove cellular debris, and participate in defending the body against invading organisms.
Leukocyte (white blood cell)
A white blood cell (leukocyte) that engulfs bacteria or other cellular debris by the process of phagocytes.
Phagocytes
Process in which some types of cells engulf bacteria or other cellular debris to break them down.
Phagocytosis
A pattern recognition receptor in innate immunity that is found on the cell surface and within the cell on various membrane bound compartments. Each type of toll-like receptor recognizes a different, specific set of molecular patterns on pathogens.
Toll-like receptors
See PAMPs.
Pathogen-associated molecular patterns
The heat, pain, redness, and swelling that occur at the site of an infection.
Inflammation
Inflammation that occurs at the site of an infection.
Local inflammation
A type of phagocytic leukocyte (white blood cell) that engulfs infected cells, pathogens, and cellular debris in damaged tissues, and helps activate lymphocytes carrying out an immune response.
Macrophages
A molecule secreted by one cell type that binds to receptors on other cells and, through signal transduction pathways, triggers a response. In innate immunity, cytokines are secreted by activated macrophages.
Cytokines
A type of cell dispersed through connective tissue that releases histamine when activated by the death of cells, caused by a pathogen at an infection site.
Mast cells
An inflammatory signaling molecule.
Histamine
A type of leukocyte (white blood cell) that enters damaged tissue from the bloodstream through the endothelial wall of the blood vessel and then differentiates into a macrophage.
Monocytes
A protein secreted by activated macrophages that attracts other cells, such as neutrophils.
Chemokines
A type of leukocyte (white blood cell) that secretes substances that help kill eukaryotic parasites such as worms.
Eosinophils
Inflammation that occurs throughout the body.
Systemic inflammation
A condition characterized by a rise in body temperature above the normal range.
Fever
Chemicals released by macrophages in response to infection that stimulate prostaglandins release from the hypothalamus thereby leading to an increase in body temperature (fever)
Pyrogens
A nonspecific defense mechanism activated by invading pathogens, made up of more than 30 interacting soluble plasma proteins circulating in the blood and interstitial fluid.
Complement system
An abnormal activation of the complement (protein) portion of the blood, forming a cascade reaction that brings blood proteins together, binds them to the cell wall, and then inserts them through the cell membrane.
Membrane attack complexes
A cytokine produced by infected host cells affected by viral dsRNA, which act both on the infected cell that produces it, an autocrine effect, and on neighboring uninfected cells, a paracrine effect.
Interferons
A type of lymphocyte that destroys virus-infected cells.
Natural killer (NK) cells
A leukocyte (white blood cell) that carriers out most of its activities in tissues and organs of the lymphatic system. The main subtypes of lymphocytes play major roles in innate and adaptive immunity.
Lymphocyte
A protein secreted by natural killer cells of the immune system that creates pores in a virus-infected cell’s membrane.
Perforin
A type of programmed cell death.
Apoptosis
A vertebrate-only defense mechanism that is activated to recognize specific molecules (free, or on the surface of pathogens or foreign cells) as foreign and to mount an attack that neutralizes them or eliminates them directly from the body.
Adaptive immunity
See adaptive (acquired) immunity.
Acquired immunity
A foreign molecule that triggers an adaptive immunity response.
Antigen
A type of lymphocyte that recognizes antigens in the body. Differentiate from stem cells in the bone marrow and are released into the blood and carried to capillary beds serving the tissues and organs of the lymphatic system. Participate in adaptive immunity.
B cells
A type of lymphocyte that recognizes antigens in the body. Are produced by the division of stem cells in the bone marrow and then released into the blood and carried to the thymus. T cells participate in adaptive immunity.
T cells
Adaptive immune response in which plasma cells secrete antibodies. Also called humoral immunity.
Antibody-mediated immunity
See antibody-mediated immunity.
Humoral immunity
A large antibody-producing cell that develops from B cells.
Plasma cells
A highly specific soluble protein molecule that circulates in the blood and lymph, recognizing and binding to antigens and clearing them from the body.
Antibodies
An adaptive immune response in which a subclass of T cells — cytotoxic T cells — becomes activated and, with other cells of the immune system, attacks host cells infected by pathogens, particularly those infected by a virus.
Cell-mediated immunity
An activated lymphocyte that circulates in the blood and lymph, ready to initiate a rapid immune response on subsequent exposure to the same antigen.
Memory cells
The receptor on B cells that is specific for a particular antigen.
B-cell receptors
A receptor that covers the plasma membrane of a T cell, specific for a particular antigen.
T-cell receptors
The region at one end of an antibody molecule, T-cell receptor (TCR), or B-cell receptor (BCR) that binds to a specific antigen.
Antigen-binding sites
The small region of an antigen molecule to which a B-cell receptor or T-cell receptor binds. Also called an antigenic determinant.
Epitope
See epitope.
Antigenic determinant
A specific protein substances produced by plasma cells to aid in fighting infection.
Immunoglobulins
The heavier of the two types of polypeptide chains that are found in immunoglobulin and antibody molecules.
Heavy chains
For the light and heavy polypeptides of a particular type of antibody molecule, the regions that have the same amino acid sequences for all molecules.
Constant (C) region
For the light and heavy polypeptides of a particular type of antibody, the regions that have different amino acids sequences from molecule to molecule.
Variable (V) region
The molecular type of an antibody determined by the constant regions of the heavy chains of the molecule.
Antibody class
The first antibody type secreted by B cells in a primary immune response.
IgM
The most abundant antibody type circulating in the blood and lymphatic system that is involved in primary and secondary immune responses.
IgG
The class of antibodies found mainly in secretions at particular locations in the body; functions to bind to surface groups on pathogens and block their attachment to body surfaces.
IgA
The class of antibodies secreted plasma cells of the skin and tissues lining the gastrointestinal tract and respiratory tract that binds to basophils and mast cells to trigger the release of histamine, thereby causing an inflammatory response.
IgE
A type of leukocyte located in blood that responds to IgE antibodies in an allergic response by secreting histamine, which stimulates inflammation.
Basophils
The class of antibodies that occurs with IgM as a receptor on the surfaces of B cells; the function of IgD is uncertain.
IgD
A type of phagocyte, so called because it has many surface projections that resemble dendrites of neurons, which engulfs a bacterium in infected tissue by phagocytosis.
Dendritic cell
A large cluster of genes encoding the MHC proteins.
Major histocompatibility complex (MHC)
A cell that presents an antigen to T cells in antibody-mediated immunity and cell-mediated immunity.
Antigen-presenting cell (APC)
A type of T cell in the lymphatic system that has CD4 receptors on its surface. This type of T cell binds to an antigen-presenting cell in antibody-mediated immunity.
CD4 + T cell
In antibody-mediated immunity and cell-mediated immunity, the proliferation of an activated T cell by cell division to produce a clone of cells.
Clonal expansion
A clonal cell that assists with the activation of B cells.
Helper T cells
A cell involved in effecting — bringing about — the specific immune response to an antigen.
Effector T cell
In antibody-mediated immunity, a long-lived cell expressing an antibody on its surface that can bind to a specific antigen.
Memory B cells
The process by which a lymphocyte is specifically selected for cloning when it encounters a foreign antigen from among a randomly generated, enormous diversity of lymphocytes with receptors that specifically recognize the antigen.
Clonal selection
One of two important mechanisms that clear foreign antigens from the body; toxins produced by an invading pathogen are inactivated (neutralized) by antibodies.
Neutralization
One of two important mechanisms to clear foreign antigens from the body, the immobilization of pathogens by antibodies.
Agglutination
In cell-mediated immunity, a long-lived cell differentiated from a helper T cell, which remains in an inactive state in the lymphatic system after an immune reaction has run its course and ready to be activated on subsequent exposure to the same antigen.
Memory helper T cells
The capacity of the immune system to respond more rapidly and vigorously to the second contact with a specific antigen than to the primary contract.
Immunological memory
The response of the immune system to the first challenge by an antigen.
Primary immune response
The rapid immune response that occurs during the second (and subsequent) encounters to the immune system of a mammal with a specific antigen.
Secondary immune response
The production of antibodies in the body in response to exposure to a foreign antigen.
Active immunity
The acquisition of antibodies as a result of direct transfer from another person.
Passive immunity
An antibody that reacts only against the same segment (epitope) of a a single antigen.
Monoclonal antibodies
A malfunction of the immune system in which the body reacts against its own proteins or cells.
Autoimmune disease
The process that protects the body’s own molecules from attack by the immune system.
Immunological tolerance
The production of antibodies against molecules of the body.
Autoimmune reaction
An autoimmune disease caused by production of a wide variety of anti-self antibodies against blood cells, blood platelets, and internal cell structures and molecules such as mitochondria and proteins associated with the DNA in the cell nucleus; characterized by anemia and problems with blood circulation and kidney function.
Systemic lupus erythematosus (lupus)
An autoimmune disease that results by a self-attack on connective tissues, particularly in the joints, causing pain and inflammation.
Rheumatoid arthritis
An autoimmune disease resulting from an attack against a protein of the myelin sheaths insulating the surfaces of neurons.
Multiple sclerosis
The time during which an animal virus (such as a pathogen) remains in an infected cell in an inactive form and cannot be isolated and identified.
Latent state
A type of antigen responsible for allergic reactions, which induces B cells to secrete an overabundance of IgE antibodies.
Allergens
Substances that block histamine receptors thereby reducing symptoms of an allergic reaction
Antihistamines
An IgE-mediated inflammatory response to allergens that chronically affects the airways of the lungs.
Asthma
A severe inflammation stimulated by an allergen, involving extreme swelling of air passages in the lungs that interferes with breathing, and massive leakage of fluid from capillaries that causes blood pressure to drop precipitously.
Anaphylactic shock
