Topic 11 Flashcards
What is an antigen?
Any foreign molecule that triggers an immune response
Is the antigen on the pathogen?
YES
What are the most common antigens?
Proteins and polysaccharides
What do the surface of our own cells contain?
Proteins and polypeptides
What does the immune system function based on?
Recognising the distinction between foreign and self antigens
What do antigens on red blood cells stimulate?
Antibody production in a person with a different blood group
What are blood groups based on?
Prescence of certain anitgens on RBCs
What are important in blood transfusions?
-ABO blood group and the Rhesus ( Rh) as mismatches can lead to an immune response
What happens when there is transfusion with the wrong blood type?
Aggultination
What is agglutination?
When the RBCs clump together
What happens after agglutination?
Hemolysis
What do beta cells produce?
Plasma and memory cells
Beta cells
- divide many times by mitosis to generate a clone of plasma cells that all produce the same anti body type
- these antibodies persist in the body for a few weeks and plasma cells are lost when infection is overcome
- small number of beta cells become memory cells and remain inactive unless reinfection occurs where they become active and respond rapidly
What is clonal selection?
Plasma cells that produce one specific antibody type
Immunity
- Due to persistance of memory cells that produce antibodies
- Develops when the immune system is challenged by a specific antigen and produces antibodies
What is secondary immune response?
When memory cells ensure that the 2nd time the antigen is encountered the body is ready to respond
Vaccines
-Contain a weakened version of the pathogen which stimulates a primary immune response so that if the micro-organism enters again it will be destroyed by the secondary immune response
Histamines
- secreted by mast cellls
- causes dilation of small blood vessels in the infected area causing them to become leaky which increases the flow of fluid containing immune components to the area
- causes allergic symptoms like rashes, nose itching, sneezing, anaphylaxis
What do anti-histamines do?
Decrease the allergic symptoms
Monoclonal antibodies
- produced by hybridoma cells ( the hybridoma divides and forms a clone where they are cultured in a fermenter and secrete monoclonal antibodies)
- can be used to test for Malaria, HIV and the creation of antibdies for injection into rabies victims
- many hybridomas are produced and they are tested to find the one that produces the required antibody
Pregnancy testing
-Use monoclonal antibodies to detect hCG which is produced by the embryo and later the placenta