What is meant by 'humoral immunity'?
An immune response that involves the destruction of pathogens using antibodies.
How many different types of B-lymphocytes exist in the body?
10 million (approx) - each one has different shaped receptors that bind to specific antigens.
B-lymphocytes can develop into which type of cells after an immune response?
Plasma cells develop from B-lymphocytes. What is their function?
They produce antibodies to destroy pathogens.
Memory cells can develop from B-lymphocytes. What is their function?
They are responsible for the secondary immune response.
If they encounter the same pathogen again they multiply rapidly and develop into plasma cells, which produce antibodies.
Describe the process of humoral immunity.
- Foreign antigen enters blood, initiating an immune response.
- A specific B-lymphocyte engulfs forein antigen via endocytosis and presents foreign antigens on its cell surface membrane.
- Th cell binds to and stimulates specfic B-lymphocyte to undergo mitosis (clonal selection).
- Cloned B-lymphocytes develop into plasma cells that produce monoclonal antibodies (primary response).
- Some B-lymphocytes become memory cells that circulate blood ready to develop into plasma cells upon a recurring infection (secondary response).
Describe how the presentation of a viral antigen leads to the secretion of antibody against viral antigens
T cells bind to the antigen (on APC)
T cells are activated in to T helper cells
T helper cells stimulate SPECIFIC B cells
B cells stimulated to divide by mitosis (clonal selection)
Forms plasma cells which release antibodies
What makes all antibodies unqiue?
Specific tertiary structure
Variable region will ONLY bind/complementary to one antigen
only forms antigen-antibody specific complexes with specific antigens
How is a secondary immune response different to a primary response
GREATER concentration in antibodies produced
No LAG/Delay in antibody production
How is passive immunity different to active immunity
No MEMORY cells produced