U3KA6 Flashcards
Why are specific body defenses abe to kill a large number of pathogens but non-specific body defenses cannot?
because they are too slow to be able to cope with large infections of the body.
what are lymphocytes?
they are white blood cells involved in the specific immune response
what are lymphocytes sensitive to?
foreign antigens, proteins on the surface of cells (pathogens and foreign cells)
How do lymphocyte activate to fight the specific infection?
antigen binds to specific lymphocyte –> triggered and divides repeatedly –> fights infection
What lymphocytes produce specific antibodies against specific antigens that leads to the destruction of a pathogen?
B-lymphocytes
What are antibodies?
they are Y-shaped proteins that have receptor binding sites specific to a particular antigen on a pathogen.
How do antibodies help phagocytosis to occur?
They become bound to antigens, inactivating the pathogen and clumping the pathogens together, resulting atigen-antibody compex then destroyed by phagocytosis.
What are issues with B-lymphocytes?
they can respond to antigens on substances that are harmless to the body, this can trigger inflammation response in that area. This called an allergic reaction.
How do T-lymphocytes destroy pathogens?
they spot the antigens displayed from the pathogens own cel membrane, they bind onto the infected cell and cause it to self-destruct. This is called apoptosis.
What is apoptosis?
its a programmed cell death.
How does apoptosis work?
T-lymphocytes release proteins into the infected cell when it binds, these proteins cause self-destruct enzymes to be produced in the cell, which causes the cell to shrivel and die.
What are the problems with T-lymphocytes?
they must be able to tell the difference between healthy, uninfected cell antigens and pathogen antigens. Sometimes mutations in the immune system cause T-lymphocytes to respond to self-antigens, which results in atacking healthy and uninfected cells.
What is called when a T-lymphocyte tells the difference between healthy, uninfected cell antigens and pathogen antigens?
recognition of self-antigens and nonself-antigens.
What are examples of autoimmune diseases?
type 1 diabetes and rheumatoid arthritis.
What does HIV stand for?
human immunodeficiency virus
