A glossary of the immune system Flashcards
What is a natural killer cell.
large granular lymphocyte that can detect and kill tumour cells and virally infected cells. they can also kill antibody-bound cells/pathogens.
What are mast cells, eosinophils and basophils.
Large granular cells that release highly inflammatory substances when activated; mast cells are tissue resident cells whilst eosinophils and basophils are found in very small numbers in the circulation in healthy, non-allergic individuals but increase in number in allergic/asthmatic individuals; all are an important defence against large antibody-coated pathogens that cannot be phagocytosed.
What are the major functions of a macrophage.
phagocytosis
pro-/anti-inflammatory
bacterial killing mechanisms
antigen presentation
wound healing/ tissue repair
What are the major functions of mast cells, eosinophils and basophils.
pro-inflammatory
parasitic killing mechanisms
linked to allergy and asthma
What is the function of a Natural killer (NK) cell
killing of virally infected cells
killing of tumour cells
What are the major functions of neutrophils
phagocytosis
pro-inflammatory
bacterial killing mechanism
What are examples of phagocytes.
monocytes, macrophages and neutrophils.
What is the function of phagocytes.
‘eating cells’ - they ingest and kill extracellular pathogens as well as dead/dying apoptotic cells and small immune complexes. they are also important sources of cytokines which regulate acute inflammatory responses; they are particularly important at sites exposed to the external tissues
What do neutrophils do
neutrophils circulate in the blood but are rapidly recruited into inflamed, damaged and infected tissues.
Where can cytokines act.
Cytokines may act on the cells that produce them, on nearby cells or on distant cells.
How are autocrine signals produced.
autocrine signals are produced by signalling cells that can also bind to the ligand that is released, which means the signalling cell and the target cell can be the same or a similar cells.
endocrine signalling occurs between which cells
endocrine signalling occurs between distant cells and is mediated by hormones and cytokines released from specific cells that travel to target cells, producing a slower, long-lasting response.
paracrine signalling occurs between which cells.
Paracrine signalling occurs between local cells where the signals elicit quick responses and last only a short amount of time due to the degeneration of the paracrine ligands.
What are cytokines.
proteins and peptides produced in response to infection, inflammation, tissue damage. They modulate behaviour of cells and so play a key role in co-ordinating the immune system.
What is the function of the cytokine interferon
anti-viral activity
