B Lymphocytes and Humoral Immunity Flashcards Preview

Biology-5-Cell Recognition and The Immune System > B Lymphocytes and Humoral Immunity > Flashcards

Flashcards in B Lymphocytes and Humoral Immunity Deck (10):

Why is it called humoral immunity

Because it involves antibodies and they are soluble in the blood and tissue fluid of the body. An old fashion word for body fluids is ‘humour’


What is clonal selection

When T helper cells bind to processed antigens and stimulate B cells to divide by mitosis to form a clone of identical B cells, all of which produce the antibody that is specific to the foreign antigen


What happens when an antibody in the surface of a B cell meets a complimentary shaped antigen?

it binds to it forming a antigen antibody complex


What do plasma cells do

They produced antibodies which help destroy the pathogen, they are responsible for the immediate defence of the body against infection.


What do B memory cells so

Remain in the blood so if there is a second exposure then the pathogen rapid mitosis division occurs. It is quicker and a greater number of antibodies are produced


What’s the primary response

When an antigen first enters the body it activates the immune system

This process is slow as there aren’t many B cells that can make the antibody needed to bind to it

Eventually it will produce enough of the right antibody to overcome the disease

Memory B and T cells will remain in the body for a long time, so they will recognise it second time round


What’s the secondary immune response

Same pathogen enters body however immune system produces quicker stronger immune response

Clonal selection happens faster. Members B cells are activated and divide into plasma cells that produce the right antibody to the antigen. Memory T cells are activated and divide into the correct type of T cells to kill the cell carrying the antigen

It gets rid of the pathogen before you show any symptoms


What’s the role of B cells in humoral immunity

1 The surface antigens of an invading pathogen are taken up by a B cell

2 The B cell processes the antigens and presents them on its surface.

3 Helper T cells attach to the processed antigens on the B cell thereby activating the B cell

4 The B cell is now activated to divide by mitosis to give a clone of plasma cells

5 The cloned plasma cells produce and secrete the specific antibody that exactly fits the antigen on the pathogen's surface.

6 The antibody attaches to antigens on the pathogen and destroys them

7 some B cells develop into memory cells. These can respond to future infections by the same pathogen by dividing rapidly an developing into plasma cells that produce antibodies. This is the secondary immune response.


Contrast the cell mediated and humoral responses to a pathogen

CM involves T cells, H involves mostly B cells

CM has no antibodies, H - anti bodies are produced

CM - first stage of immune response
H- second stage of immune response

CM- effective through cells
H- effective through body fluids


Suggest 3 cell organelles that you might expect to find in large quantities in a plasma cell. Explain why

RER- to make and transport the proteins of the antibodies

Golgi apparatus- sort process and compile the proteins

Mitochondria - release energy for such massive antibody production