immunity flashcards

antigen

a molecule or part of molecule that elicits an immune response

antibody

a protein produced by the body that recognises foreign antigens and neutralises it

pathogen

an organism that can produce disease in another organism

immunogen

any substance or molecule that can elicit an immune response

bacteria

cellular prokaryotes that have cell walls but lack a nucleus and organelles

fungi

non-phototrophic eukaryotes that have rigid cell walls made from chitin

oomycete

fungus-like pathogen of plants with branching hyphae

protozoan

a unicellular, eukaryotic organism that may have multiple stages in a complete life cycle; replicates in its host’s cells

arthopods

invertebrate animals of the large phylum Arthropoda

viruses

an infectious agent composed of genetic material (DNA or RNA) enclosed in a protein coat

viroid

an infectious agent of plants that is a type of self-cleaving RNA enzyme (ribozyme)

prion

a small protein particle that, when its shape is altered due to mutation, causes protein aggregation and is toxic to neurons

T lymphocytes

B lymphocytes

types of leukocytes

macrophages, neutrophils, mast cells, monocytes, basophils, eosinophils, dendritic cells, natural killer cells

granulocytes

neutrophil

granulocyte, phagocytosis, release antimicrobial compounds, release cytokines to attract other immune cells to the infection site

basophil

granulocyte, releases histamine, key role in inflammation

eosinophil

granulocyte, release cytokines and cytotoxic chemicals from cytoplasmic granules, major defence against parasites that are too large for phagocytosis

mast cells

granulocyte, releases histamine, releases chemical signals to attract other immune cells to the site of infection

monocyte

precursor for macrophages, circulates in blood, can be antigen presentation cells

phagocytes

leukocytes that are able to engulf and break down pathogens thorough phagocytosis

macrophages

phagocytosis, remove dead cells and debris, antigen presentation cells, releases cytokines

dendritic cells

phagocytosis, many grooves to increase surface area and allow contact with a large number of nearby cells, antigen presentation cells, secretes antiviral cytokines

phagocytosis

the process of a leukocyte engulfing and breaking down a pathogen, dead cells, or debris.

natural killer cells

recognises virus-infected and cancerous cells, releases cytotoxic chemicals from granules, releases cytokines to attract and activate immune cells from the adaptive response

major histocompatibility complex

a group genes that code for proteins that code for proteins on the surface of cells that involved in antigen presentation

MHC class 1 markers (MHC-I)

proteins on all nucleated cells as self antigen markers that present intracellular antigens

MHC class 2 markers (MHC-II)

proteins found on the surface of antigen-presenting cells (APCs) which present extracellular antigens

physical barriers in animals

skin, tears, mucous, cilia

physical barriers in plants

bark, waxy cuticle, leaf orientation

chemical barriers in animals

stomach acid, digestive enzymes, antimicrobials

chemical barriers in animals

alkaloids, phenolics, saponins

microbiological barriers in animals

normal flora in the gut

what does innate immunity mean?

non-specific, rapid immunity that consists of non-specific cellular defences and physical and chemical barriers.

cytokines

group of peptides and/or proteins that are important for cell signalling

interferons

cytokines that act on cells infected by viruses by activating the cell to produce enzymes that break down the viral RNA and proteins that block translation.

chemokines

cytokines that act as chemical attractants to attract leukocytes to an infection site