Definitions Flashcards
Define immunology.
The study of our protection from invading foreign organisms and our responses to them
Define an antigen
An antigen is a molecule that provokes the production of antibodies by your immune system
An antibody generating compound
Define autoimmunity.
Where the immune system malfunctions and attacks the patient’s own cells and tissues
Define innate immunity
Response is exactly the same every time you are exposed to that pathogen
Define adaptive immunity
Response develops to an infection and adapts to recognise, eliminate and remember that specific pathogen
What are polymorphonuclear granulocyte?
Granulocytes with multi-lobed nuclei
What is haematoxylin?
A basic dye that stains acidic structure blue/purple
What is eosin?
An acidic dye that stains basic structures in the cytoplasm red/pink
Define phagocytosis.
The engulfment and destruction of microorganisms
What are plasma cells?
B cells that have become able to excrete antibodies
What are natural killer cells?
Cells that are a specialised type of lymphocyte that attack and kill virus-infected as well as cancerous cells
What are CD molecules?
Clusters of differentiation molecules
What is pinocytosis?
A mechanisms by which cells can “drink” liquid from outside
What is opsonisation?
2
The process by which components of the immune system found in the serum make the target more attractive for phagocytes
Opsonins = Activated complement components or antibodies
What are antibodies?
Y-shaped protein molecules produced by B cells that can identify and neutralise pathogens
What are cytokines?
2
Protein molecules that are secreted by cells of the immune system
They bind to receptors on the target cells and initiate signalling cascades that ultimately alters gene expression
What is complement?
2
A collection of over 30 proteins found in the bloodstream
Opsonisation, inflammation, lysis (MAC)
What is MAC?
2
Membrane attack complex
Makes a pore in the bacterial surface which causes the cell to swell and burst
What is interleukin 6?
2
A cytokine
It induces the liver to synthesis acute phase proteins including complement proteins
What is interleukin 1?
2
A cytokine -> released by wbcs in response to pathogen exposure
It acts upon the hypothalamus to bring about an increase in body temperature (fever)
What are type I interferons?
4
A cytokine
Interferons are released by a virus infected cell
Interferons bind to nearby healthy cell
Interferons stimulate healthy cell to make antiviral proteins that prevent viral replication
What is an allergy?
An inappropriate immune response
What are mast cells?
Cells which respond to tissue damage or products of the immune system and release multiple factors including histamine
What is extravasion?
Endothelial cells upregulate expression of “adhesion molecules” that allow white blood cells to stick and cross over into tissue
What is maturing in terms of lymphocytes?
The process by white lymphocytes make a receptor
What are immature lymphocytes?
Lymphocytes without a receptor
What are naive lymphocytes?
Lymphocytes which have a receptor
What are antigen presenting cells?
3
Cells which phagocytose pathogens, kill them and chop them up into parts
They then display fragments of pathogen on proteins on their cell surface
If peptide bind to T cell receptor then the cells becomes activated
What is MHC?
Major histocompatibility complex
What is a TLR?
Toll Like Receptor
Receptor that detects PAMS such as LPS and instruct APC to present antigens to T-cells
What do CD8 cells do?
Killer T cells
Kill virus infected or tumour cells
What are CD4 cells?
4
Helper T cells
Produce cytokines:
Activate B cells, macrophages, eosinophils. CD8 cells
What are antibodies?
2
Specific immune proteins synthesized and released by plasma cells (activated-B cells)
Soluble versions of the B cell receptor
What is natural immunity?
Where you have been exposed to the pathogen
What is artificial immunity?
Where you have been vaccinated
What is active immunity?
Where your immune response has been necessary
Antigen presentation, T-cell activation, B-cell activatin
What is passive immunity?
Where you have been given pre-formed antibodies
What is the lymphatic system?
The lymphatic system consists of a complex network of specialised cells and organs designed to protect and defend the body against attacks by “foreign” invaders such as
bacteria and viruses
What is lymph?
Plasma seeps through capillaries into the surrounding tissue (interstitial fluid)
The remaining fluid not returned to blood is lymph
What are lymphoid follicles?
3
Solid, packed, spherical clusters of lymphoid cells & reticular tissue
Often have lighter-staining centres, germinal centres (GCs) – B cells
predominate
Often found as parts of larger lymphoid organs
What are primary follicles?
They contain small resting B-cells and follicular dendritic cells
What are secondary follicles?
Rings of packed B cells surrounding germinal centres where B-cell proliferation is occurring (reproduction)
What are primary lymphoid organs?
Where lymphocyte maturation occurs
What are secondary lymphoid organs?
Organs that increase the chances that a lymphocyte will encounter it’s antigen
What are lymph nodes?
2
Encapsulated, bean-shaped structures
Clustered at junctions of lymphatic vessels
