TOPIC 2- Antigens Flashcards
What is an antigen?
Molecules (usually proteins) that can generate an immune response when detected in the body
Where are antigens usually found?
On the surface of cells
What are foreign antigens?
Antigens that aren’t normally found in the body
What do antigens allow the immune system to identify?
-Pathogens
-Abnormal body cells
-Toxins
-Cells from other individuals of the same species
What are pathogens?
Organisms that cause disease
What do all pathogens have on their surface?
-Antigens
How are pathogens destroyed?
-They are identified as foreign by immune system cells
What are abnormal body cells?
-Cancerous/pathogen-infected cells which have abnormal antigens on their surface which could trigger an immune response
What are toxins?
-Poisons
-Molecules not cells
-It is an antigen
Why can an immune response develop due to receiving other people’s cells such as a blood transfusion or organ donation?
-Those cells may have different antigens than yours
-They will be recognised as foreign antigens
Why do people with transplanted organs need to take immunosuppressants?
-The organ may be rejected
What are the most important antigens for blood transfusions?
-ABO
-If donated blood contains antigens that aren’t recognised by the recipients immune system then an immune response will be produced
