Dealing with disease + Immunity Flashcards
Pathogen
An agent that causes disease
Antigen
Any molecule that may trigger an immune response
Major histocompatibility complex (MHC) markers
A group of proteins present on the surface of all self-cells that enables the immune system to distinguish it from non-self material.
Major histocompatibility complex class II (MHC Class II) markers
Expressed on antigen presenting cells, which interact with T helper cells in the process of antigen-presentation, initiating an adaptative immune response.
Allergen
A non-pathogenic antigen that triggers an allergic reaction.
Allergic reaction
An overreaction of the immune system to a nonpathogenic antigen.
Types of cellular pathogens
Bacteria, fungi, worms, protozoa
Protozoa
Single-celled eukaryotes that can be free-living or parasitic.
Types of non-cellular pathogens
Viruses, prions
Virus
Non-cellular agent composed of a protective protein coat and nucleic acid.
Prion
Abnormally folded proteins that have the ability to induce normal proteins nearby to become misfolded.
Innate immune system
A component of the immune system that is composed of generalised and non-specific defences and/or responses to pathogens.
First line of defence
A component of the innate immune system characterised by the presence of physical, chemical, and microbiological barriers to keep pathogens out of the host organism.
Second line of defence
A component of the innate immune system characterised by the nonspecific response to injury and/or pathogens by a variety of cells and molecules.
Physical barrier
A component of the first line of defence that features solid or fluid obstacles that block pathogen entry such as skin or mucus.
Chemical barrier
A component of the first line of defence that features the use of enzymes, toxins, and acids to protect against pathogen invasion.
Cuticle
A waxy protective film covering the surface of a plant leaf.
Gall
An abnormal outgrowth of tissue in plants designed to limit the spread of an invading pathogen.
Trichomes
Small hairs on the surface of plants used to deter pathogens and/or insects
Stoma
A small pore on the leaf’s surface that opens and closes to regulate gas exchange.
Microbiological barrier
A component of the first line of defence in which the presence of normal flora limits the growth of pathogenic bacteria.
Flora
Naturally occurring, nonpathogenic bacteria present in an organism.
Cillium
Thin, hair-like projection that protrudes from eukaryotic cells.
Phagocyte
A group of leukocytes responsible for the endocytosis and destruction of pathogens, foreign material, and cell debris.
Neutrophil
The most common type of leukocyte in the body. Engages in phagocytosis of pathogens and foreign material, as well as the release of cytokines.
Macrophage
A type of leukocyte found throughout the body that engages in phagocytosis and antigen presentation.
Dendritic cell
A type of leukocyte that engages in phagocytosis and antigen presentation.
Antigen-presenting cell (APC)
A subgroup of phagocytes that display antigens from consumed pathogens on their surface and interact with the adaptive immune system.
Cytokine
A signalling molecule released by cells (typically in the immune system) which aids in communication between immune cells and helps protect against pathogens.
Natural Killer (NK) cell
A type of leukocyte responsible for the recognition and destruction of damaged and/or infected host cells.
Mast cell
A type of leukocyte responsible for releasing histamine during allergic and inflammatory responses.
Degranulation
The release of granule contents from a cell.
Histamine
A molecule released by mast cells that plays a key role in inflammation.
Inflammatory response
A series of biochemical events that occur in the body as a result of infection and/or trauma. Characterised by swelling, redness, pain, and heat in the affected tissue.
Eosinophil
A large granular leukocyte responsible for the release of toxic chemical mediators.
Interferon
A cytokine released by virally infected cells that increases the viral resistance of neighbouring uninfected cells.
Complement proteins
A number of different types of proteins found in the blood that opsonise, cause lysis, and attract phagocytes to invading pathogens.
Epidemic
The RAPID spread of disease to a large number of people.
Pandemic
When the spread of disease reaches GLOBAL proportions.
Complement cascade
A complex sequence of events which occurs after the activation of complement proteins.
Opsonisation
The mechanism by which complement proteins attach to the surface of pathogens, making them easier to phagocytose.
Chemotaxis
The attraction of phagocytes towards a pathogen.
Lysis
The disintergration or rupturing of a cell.
Membrane attack complex (MAC)
A pore formed by complement proteins in the cell membranes of a pathogen, disrupting the membrane and leading to the pathogen’s destruction.
Vasodilation
The widening of blood vessels
Third line of defence
Composed of the humoral and cell-mediated responses which create a specific immune response and form immunological memory.
Immunological memory
The ability of the immune system to
quickly and aggressively combat a previously encountered pathogen due to the presence of T and B memory cells.
T helper cell
A type of differentiated T lymphocyte that supports the functioning of a number of different immune cells, including the cloning and differentiation of selected T and B cells.
Lymphatic system
A large network of vessels and tissues throughout the body that form an important component of both the circulatory and immune systems.
Lymph node
A small secondary lymphoid tissue of the lymphatic system where antigen-presenting cells activate the adaptive immune system.
Humoral immunity
An adaptive immune response in which extracellular pathogens are targeted by specific antibodies produced by plasma cells.
Cell -mediated immunity
An adaptive immune response in which infected or abnormal cells are destroyed by cytotoxic T cells.
B lymphocyte
A type of lymphocyte that plays an important role in humoral immunity and differentiates into plasma cells and B memory cells.
Antibody
A protein produced by plasma cells during the adaptive immune response that is specific to an antigen and combats pathogens in a variety of ways.
Cytokine
A signalling molecule released by cells (typically in the immune system) which aids in communication between immune cells and helps protect against pathogens.
Clonal expansion
The process in which many copies of a lymphocyte are generated.