Immunity and vaccinations Flashcards
(38 cards)
what is an antigen?
A foreign substance introduced into the body which stimulates an immune response
what are antibodies?
proteins produced as part of the immune response, to an antigen which it then neutralises, tags or destroys
what is an antiserum?
A blood serum containing antibodies against specific antigens, injected to treat or protect against specific diseases
what is active immunity?
Immunity produced in response to a disease organism or vaccine
what is a pathogen?
An agent causing disease. Usually a living microorganism (viruses, bacteria, fungi, protozoa, parasites and prion)
what is a memory cell?
cell remaining after an immune response capable of an immediate response to reappearance of same antigen. Include certain subsets of T- and B- cells
what is primary immune response?
the immune response occurring on the first exposure to an antigen, with specific antibodies appearing in the blood after a multiple day latent period
what is secondary immune response?
the immune response occurring on second and subsequent exposures to an antigen, with a stronger response to a lesser amount of antigen, and a shorter lag time compared to the primary immune response
how does the immune response work?
- a foreign body is introduced
- the body responds by enabling the lymphocytes to produce specific antibodies to fight against the antigen
- antibodies bind on to the antigen and inactivates it
what is the immune response that involves B lymphocytes called?
humoral immunity
what is the immune response that involves T lymphocytes called?
cell mediated immunity
what is cell mediated immunity?
- does not involve antibodies
- T lymphocytes manufacture chemical messengers (cytokines) that direct the immune response
what are the 3 types of T lymphocytes?
- helper T cells
- cytotoxic T cells
- suppressor T cells
what do helper T cells do?
recognise the processed antigen and co-ordinate macrophages and B cells in the immune response
what do cytotoxic T cells do?
destroy cells infected with intracellular pathogens like viruses
what do suppressor T cells do?
keep the immune system reactions in check
what are the three levels of the immune system?
- physical barrier (skin/surfaces)
- innate immunity (pre existing enzymes)
- acquired immunity (cells/antibodies that are produced)
what is acquired immunity?
- involves the development of specific antibodies in response to specific antigens
- acquired by the animal continuously throughout its life
what are the two types of acquired immunity?
- active
- passive
what is natural active acquired immunity?
antibodies are produced in the body by lymphocytes in response to the animal actually having had and survived the disease
what is artificial active acquired immunity?
involves the introduction of an inactivated form of the disease into the animal’s body to encourage the lymphocytes to produce antigens (vaccine)
what is natural passive acquired immunity?
neonates can pick up maternally derived antibodies via colostrum in the first weeks of life
what is artificial passive acquired immunity?
- an animal receives antibodies from another animal in the form of antiserum
- instant protection against disease
what is passive immunisation?
immediate but temporary and cannot be re-stimulated by eexposure
