Humoral immunity is the use of antibodies to rid of the pathogen. (humour meaning body fluids i.e. blood as that’s where the antibodies are transported in). In the body, there are over 10 million different B cells, each with a different variable region on its membrane bound antigens that are specific to one type of antigen. B cells do not leave the lymph nodes, rather their antibodies do and travel to the required areas via the circulatory system.

  1. The pathogen is taken up by the B-cells
  2. The B-cells breaks the pathogen down and presents its antigens on the cell surface membrane as processed antigens, as well as antibodies. These antibodies are membrane bound, meaning that they are fixed to the membrane of the B-cell. These antibodies are unique to each B-cell.
  3. T helper cells attach to the processed antigens on the B-cells resulting in them becoming activated
  4. The B-cells now divide through mitosis to produce a plasma cell that produce antibodies with the correct variable region for the antigen on the pathogen. Plasma cells only live for a few days but however
  5. The antibodies produce attach themselves to the antigen on the pathogen and destroy them. This is a primary immune response.
  6. Some of the B cells then go onto develop into memory cells which remain in the body for decades with the ability to produce antibodies rapidly in the event of reinfection by the same pathogen. This is a secondary immune response.