Lymphoctyes and the Immune Response Flashcards
1
Q
Where do B lymphocytes mature
A
Bone marrow
2
Q
Where do T lymphocytes mature
A
Thymus gland
3
Q
Types of T lymphocytes
A
T killer
T helper
T memory
T regulator
4
Q
T helper cells
A
- CD4 receptors on their cell surface membrane which bind to the surface antigens on APCs
- produce interleukins ( type of cytokine - cell signalling molecule )
- interleukins made by the T helper cells stimulate the activity on the B cells which increases antibody production , stimulates production of other types of T cells and attracts & stimulate macrophages to ingest pathogens with antigen- antibody complexes
5
Q
T killer cells
A
- destroy the pathogen carrying the antigen
- produce a chemical called perforin
- which kills the pathogen by making holes in the cell membrane so it is freely permeable
6
Q
T memory cells
A
- live for a long time
- apart of immunological memory
- if they meet a antigen a second time they divide rapidly to form many clones of T killer cells that destroy the pathogen
7
Q
T regulator cells
A
- cells suppress the immune system acting to control and regulate it
- stop the immune response once a pathogen has been eliminated
- make sure the body recognises self antigens and does not set up an autoimmune response
- interleukins are important in this control
8
Q
Main types of B lymphocytes
A
- plasma cells
- B effector cells
- B memory cells
9
Q
Plasma cells
A
- produce antibodies to a particular antigen and release them into the circulation
- an active plasma cell only lives for a few days but produces around 2000 antibodies per second while it is alive and active
10
Q
B effector cells
A
These divide to form the plasma cell clones
11
Q
B memory cells
A
- live for a long time and provide immunological memory
- they are programmed to remember a specific antigen and enable the body to make a very rapid response when a pathogen carrying that antigen is encountered again
12
Q
Cell mediated immunity
A
T lymphocytes respond to the cells of an organism that have been changed in some way for eg. By a virus infection, by antigen processing or by mutation
13
Q
Non specific defence system
A
- Macrophages engulf and digest pathogens in phagocytosis
- process antigens from the surface of the pathogen to form antigen presenting cells ( APCs) - Receptors on some of the T helper cells fit the antigens
- these T helper cells become activated and produce interleukins which stimulate more T cells to divide rapidly by mitosis
- they form clones of identical activated T helper cells that all carry the right antigen to bind to a particular pathogen
14
Q
The cloned T cells may :
A
- develop into T memory cells which give a rapid response if this pathogen invades the body again
- produce interleukins that stimulate phagocytosis
- produce interleukins that stimulate B cells to divide
- stimulate the development of a clone of T killer cells that are specific for the presented antigen and then destory infected cells
15
Q
Humoral immunity
A
Body responds to antigens found outside the cells for eg. Bacteria and fungi
