Topic 2- B lymphocyte response Flashcards
Where do B cells remain until they are mature?
In the bone marrow
Where do they spread until they are mature?
-Around the body specifically:
-Lymph nodes
-Spleen
Why are so many B cells produced?
as they mature, the genes coding for antibodies are changed to code for different antibodies
What happens when B cells are mature?
can make one type of antibody molecule
Where are the antibodies located?
The cell surface membrane
Part of each antibody molecule forms a 1.__________ _______ that can combine specifically with one type of 2.
- glycoprotein receptor
2.antigen
What will happen if that antigen enters the body, B-lymphocyte cells with the correct cell surface receptors ?
will be able to recognise it and bind to it (clonal selection)
These specific B-lymphocytes divide repeatedly by mitosis (clonal expansion) and differentiate into two main types of cell what are they?
-Plasma cells
-Memory cells
Describe what happens in clonal selection
When an antigen enters the body for the first time, the small numbers of B-lymphocytes with receptors complementary to that antigen are stimulated to divide by mitosis
What is the 1st step of the primary immune response?
-Clonal selection
What is the 2nd step of the primary response?
-Clonal expansion (Clones divide repeatedly by mitosis)
-Results in large numbers of identical B-lymphocytes being produced over a few weeks
What is the 3rd step of the primary response?
-Some of these B-lymphocytes become plasma cells that secrete lots of antibody molecules (specific to the antigen) into the blood, lymph or linings of the lungs and the gut
What is the 4th step of the primary response?
-These plasma cells are short-lived (their numbers drop off after several weeks) but the antibodies they have secreted stay in the blood for a longer time
What is the 5th step of the primary response?
The other B-lymphocytes become memory cells that remain circulating in the blood for a long time
Is the primary response slow or fast?
Slow
