Biology: Chapter 6 - Responding to Pathogens

adaptive immune response

an immune response targeted at a specific antigen

can “remember” an antigen so that it can respond effectively upon subsequent exposure

allergen

a normally innocuous antigen that can cause an overreaction from the immune system known as an allergy

allergy

an immune system response characterised by IgE (Immunoglobulin E) production to an innocuous substance

anaphylactic shock

a severe allergic reaction that causes widespread swelling, including of the face and neck, that can lead to difficulty breathing

antibiotic

a naturally or synthetically produced compound that is toxic to bacteria

antigen

a large molecule, usually a protein or polysaccharide, that generate an immune response

apoptosis

a programmed series of events that lead to cell death as a result of the dismantling of the internal contents of cells by various enzymes, including caspases

bacteria

unicellular prokaryotes that can be pathogenic and therefore carry disease

bacterial capsule

a polysaccharide layer surrounding some bacteria that makes them resistant to phagocytosis and thus more virulent

cellular pathogen

a disease causing pathogen that is made up of one or more living cells such as bacteria or fungi

chemokine

a type of cytokine that induces chemotaxis

chemotaxis

the movement of an organism or a cell along a chemical concentration gradient either towards or away from a chemokine

cilia

slender hair-like structures projecting from a cell surface that beat against fluid

companion plant

a plant that is grown with another plant because one species improves the growth of the other

complement

a number of small proteins found in blood that, when activated, promote chemotaxis, cell lysis, and phagocytosis

cytokine

a signalling molecule that coordinates inflammation and immune responses and that leukocytes use to communicate with one another; includes interleukins and interferons

defensin

a type of small antimicrobial peptide secreted by nearly all plants and animals

degranulation

a cellular process in which the granules of neutrophils, mast cells, basophils, or eisinophils are emptied into extracellular surroundings

dendritic cell

a phagocyte with membranous extensions that engulf pathogens, process them and present them to other cells of the immune system

desensitisation

a treatment to make a person more tolerant of a substance to which they are allergic

disease

any condition that interferes with how an organism, or any part of it, functions

eosinophil

a leukocyte that secretes powerful enzymes capable of rupturing multicellular organism

first line of defence

physical and chemical barriers that keep pathogens from entering the body of a living thing

flagellum

a helical filament that rotates to give bacteria locomotion

fungus

a heterotrophic organism made up of one or many cells; has cell walls but is not a plant

granulocyte

a white blood cell that has granules in the cytoplasm

histamine

a chemical released by mast cells and basophils that increase blood flow and the permeability of capillaries

host

the organism in which a parasite lives

immune system

a complex network of cells, tissues and organs in the body that detect differences between self molecules and foreign (non-self) organisms, and mounts an immune response that results in the formation of memory lymphocytes

immune tolerance

tolerance of the presence of an antigen by the immune system so it does not mount an immune response to an antigen

infectious disease

a disorder caused by bacteria, viruses, fungi and other organisms, that can often be transmitted to other members of a population

inflammation

an innate response to infection or damage that causes pain, swelling, heat, and redness

innate immune response

a response to a pathogen that is not specific to an antigenm only that is has been identified as being non-self; the response does not generate antibodies or memory lymphocytes

interferon

a type of cytokine produced by the cells of an immune system in response to challenges by foreign agents such as viruses, bacteria, parasites, and tumour cells

keratin

the tough, fibrous protein of the outer epidermis layer

leukocyte

the general term for a white blood cell

lymphocyte

a type of leukocyte involved in adaptive immune responses

lysis

the process of a cell bursting

lysozyme

an antibacterial enzyme found in tears, saliva, and other bodily fluids

macrophage

a large white blood cell that phagocytoses pathogens; originates as monocytes in circulation

mast cell

a cell that is located in the tissues and releases granules containing histamines when activated

microbiome

the bacteria, viruses and fungi that live