Biology 6.4 B Cells and Humoral Immunity

Humoral immunity

Humoral immunity = involves antibodies, which are soluble in blood and tissue fluid.

Humour = body fluids.

Many different types of B cells - each makes a different antibody that responds to a different antigen.

Only one type of B cell with have a complementary antibody with a shape that fits a specific antigen.

Antibody attaches to complementary antigen and B cell divides by mitosis.

NB: B cells are present from birth, they are not produced in response to pathogen, the original just multiplies.

Toxin molecules from pathogens also act as antigens, so many different B cells will make clones which produces its own type of antibody.

The cells produced from each clone develop into one of two types of cell:

• Plasma cells = secrete antibodies directly, only survive for a few days, antibodies produced destroy the pathogen as well as toxins it produces - responsible for immediate defense…