5.4 - B Lymphocytes And Humoral Immunity Flashcards
What does humoral immunity involve?
Antibodies
When an antigen enters the blood or tissue fluid what will the B cell have for it?
The B cell will have a antibody on its surface whose shape exactly fits the antigen - they are complemetary
How does the antigen enter the B cells invaded by?
Endocytosis
What is clonal selection?
When the T cells bind to the processed antigens and stimulate it to divide by mitosis to make lodes of clones of B cells that all produce the same antibodies
As each clone produces one specific antibody it is called what?
Monoclonal antibodies
In each clone of B cell they deivide into two diffrent cells which are?
- Plasma cells
- Memory cells
What do plasma cells do?
Secrete antibodies usually into the blood plasma
How long do plasma cells usually last
Only a few days
The production of antibodies and memory cells is knows as the?
Primary immune response.
What are memory cells responcible for?
The secondary immune response
Do memory cells live for shorter or longer than plasma cells?
Longer, often up to decades
What do memory cells do?
Circulate in the body fluid, when then encounter the same antigen at a later date they divide rapidly into plasma cells which secrete antibodies.
Give the summery of the role of B cells in humoral immunity
- The surface antigens of an invading pathogen are taken up by B cells to divide
- The B cell process this antigen and presents it on its surface
- Helper T cells can attaches to processed antigen and stimulates the B cell to divide by mitosis to give a clone of plasma cells
- The plasma cells secrete their antibodies D antibodies complementary to the antigen
- Antibodies attach to the antigens on the pathogens destroying them
- Some B cells turn into memory cells - respond to future infections
