Chapter 6 - Immunity Flashcards
What is a lymphocyte?
Type of white blood cell responsible for an immune response. Activated by the presence of antigens. (B and T cells)
What type of immunity does a B lymphocyte trigger?
Humoral immunity
What type of immunity does a T lymphocyte trigger?
Cell mediated immunity
Describe cell mediated immunity
T lymphocytes respond to an organisms own cells that have been invaded by non self material
What do T cells respond to?
Antigens that are attached to a body cell
What is the process of T cell response?
- Body cells presents antigen on surface
- T helper cell receptors attach to antigen
- Activates other T cells to divide by Mitosis
- Some form memory cells
- Some stimulate B cells to divide
- Some also stimulate phagocytosis
Process of B Cell immunity
- Each type produces a different antibody that responds to specific antigen
- Antigen that enters the blood will have one type of B cell who’s structure is complementary to fit the antigen
- Complementary B cells multiply by mitosis producing many specific antibodies.
What is a primary immune response?
Plasma cell production from B cells
Destroy pathogens and toxins produced
Immediate defence
What is secondary immune response?
When B cells encounter an antigen they divide rapidly to produce plasma cells.
Plasma cells produce antibodies which then circulate round the body
Why does antigenic variability happen?
Some diseases have many strains with changing antigens
Definition of an antibody?
A protein produced by lymphocytes in response to the presence of the appropriate antigen
What is an antigen made up of?
4 polypeptide chains
One pair of heavy chains
One pair of lighter chains
How is an antigen-antibody complex formed?
Antibodies change shape to fit around antigens
They have a binding site that fits precisely onto the antigen
What is a monoclonal antibody?
Antibodies produced from the same B cell
What is passive immunity?
Immunity produced by the introduction of antibodies into individuals from an outside source
