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Flashcards in Immunology Deck (21):

Define innate defence mechanisms

+ Primary line of defence

+ Not improved by further exposure

+ Immediate responder


Define adaptive defence mechanisms

+ Secondary line of defence

+ Improved by further exposure

+ involves antibody responses and
cell mutating responses

+ Specificity and

+ Memory cells

+ Takes time to respond (days-weeks)


Name physical defence mechanisms

+ Skin, epithelia (barriers)

+ Cilia (movement)

+ Mucus (trapping)


Name biochemical defence mechanisms

+ Low pH

+ Sweat

+ Vaginal secretions

+ Stomach secretions

+ Lysozyme secretions


Name types of chemical blood bourne agents released by immune system

+ Acute phase proteins

+ Complement proteins

+ Interferons

+ Cytokines


What are complement proteins?

They are a cascade of blood proteins which are involved in a defence mechanism. Starts from C1 to C9


What are cytokines?

They are small proteins that communicate between cells in the immune system


What is CRP?

+ C-reactive protein

+ Sign of ongoing Inflammation

+ Indicator that can change extremely rapidly within a couple hours of inflammatory response occurring

+ Normal levels ~5mg/L


What is chemotaxis?

The movement of anorganism in respinse to a chemical signal - used to attract phagocytes to site of infection


What is an opsonin?

A substance that coats the cell/bacteria and enhances the ability of phagocytes to phagocytose the particle.


What is opsonisation?

The process of coating cell/bacteria with an opsonin.


What is an interferon?

A protein released by cells usually in response to the entry of a virus, which has the property of inhibiting virus replication.


What do IFNα, IFNβ and IFNγ do?

IFNα and IFNβ

+ Make surrounding cells more resistant
+ can be used by all different types of cells, especially leucocytes and fibroblasts


+ Make surrounding cells more resistant
+ is used in immune cells mostly


What is a T-cell?

T-lymphocyte: a lymphocyte of a type produced or processed by the thymus gland and actively participating in the immune response.


What are NK cells?

Natural killer cells/K cells:
A type of lymphocyte and a component of innate immune system. NK cells play a major role in the host-rejection of both tumours and virally infected cells.


What are the features of an antibody?

+ Specificity for antigens

+ Recognition site

+ Protective functioning

+ Monocytes binding

+ Complement fixation


What are the three types of complement function?

+ Lysis

+ Chemotaxis

+ Opsonisation


What is autoimmunity?

+ The immune system reacting to itself

+ Loss of tolerance

+ Response can be antibody or cell mediated


What are features/functions of lymphocytes?

+ Type of white blood cell that function as part of the immune system

+ Their various functions allow them to properly respond to foreign invaders in the body

+ Some lymphocytes work alone, while others are able to coordinate with other cells.


What are some examples of failure of the immune system?

+ Rheumatoid arthritis

+ IDDM (insulin dependent diabetes mellitus): autoantibodies destroying insulin producing cells

+ Immunological damage to thyroid gland: Hashimoto's thyroiditis


What are consequences of failure of the immune system?

+ Hypersensitivity
+ Immunodeficiency
+ Autoimmunity