Unit 3.6 - Specific Cellular Responses Flashcards
What are lymphocytes?
The white blood cells involved in the specific immune response
What do you lymphocytes respond to?
Specific antigens on the invading pathogen
Explain clonal selection theory
Lymphocyte with a specific membrane receptors recognises and binds with a specific antigen
The specific lymphocyte divide to produce many identical lymphocytes clones with that receptor site
What does the antigen binding to the sites lead to?
Repeated division of the lymphocyte, resulting in a clonal population of identical lymphocytes
What are antigens?
Molecules located on the surface of cells that trigger a specific immune response
Explain the role of T lymphocytes
T lymphocytes destroy infected body tissue
They recognise the foreign antigens of the pathogens which are displayed on the membrane of cells they have infected
T lymphocytes bind to these antigen specifically and release proteins which diffused into the infected cell
These proteins cause the sale to produce self-destructive enzymes which causes cell death (apoptosis)
The remains of the cells are then removed by phagocytosis
What is a auto immune disease?
A failure by T lymphocytes to recognise self antigens
What happens in autoimmunity?
The T lymphocytes attack the body’s own cells
What are examples of autoimmune diseases?
Type 1 diabetes
What do B lymphocytes produce?
Antibodies against antigens and this leads to the destruction of the pathogen
What are antibodies?
Y shaped proteins that have receptor binding sites specific to a particular antigen on a pathogen
Antibodies become bound to antigens, inactivating the pathogen
The resulting antigen - antibody complex can then be destroyed by phagocytes
What do B lymphocytes secrete?
Antibodies into the lymph and blood that make their way to the infected area
What is an allergy?
A normally harmless hypersensitivity by B lymphocytes to an antigen
What are memory cells
B and T lymphocytes produced as a result of clonal selection that survived long term
What can memory cells do?
When a secondary exposure to the same antigen is occurs they can rapidly give rise to a new clone of specific lymphocytes that destroy the invading pathogen is before the individual shows symptoms
