definitions Flashcards
Define a pathogen
It is an organism that causes disease
Define immunity
Immunity is the ability to resist infection
Define general defence system
It acts as a barrier to all pathogens attempting to gain entry to the human body
Define specific defence system
It attacks particular (specific) pathogens
Define antigen
It is a foreign molecule that stimulates the production of antibodies
Define antibody
It is a protein produced by white blood cells (lymphocytes) in response to a specific antigen
Define induced immunity
It is the ability to resist disease caused by specific pathogens by the production of antibodies
Define active immunity
It involves the production of a person’s own antibodies in response to foreign antigens that enter the body.
Define natural active immunity
It occurs when a pathogen enters the body in the normal way (i.e. when you get an infection)
Define artificial active immunity
It occurs when a pathogen is medically introduced into the body
Define vaccine
It is a non disease-causing dose of a pathogen (or its toxin), which triggers the production of antibodies.
Define passive immunity
It occurs when individuals are given antibodies that were formed by another organism
Define natural passive immunity
It occurs when a child gets antibodies from its mother
Define artificial passive immunity
It occurs when a person is given an injection containing antibodies made by another organism
Define plasma B cells
They produce antibodies
Define memory B cells
They survive for years after the infection is eliminated and can make the specific antibody if the same infection later enters the body
Define Helper T cells
They stimulate B cells and killer T cells
Define killer T cells
They destroy abnormal human body cells
Define suppressor T cells
They inhibit the immune response
Define memory T cells
They survive for years after the infection is eliminated and can stimulate the specific B cells and killer T cells if the same infection later enters the body
Define vaccination
It is the administration (usually by injection) of a non-disease-causing dose of a pathogen (or its toxin) to stimulate the production of antibodies.
Define immunisation
It occurs when we produce or are injected with antibodies against a pathogen
