4.1 Communicable diseases Flashcards
What is clonal selection?
Selection of a specific B or T cell that is specific to the antigen.
What is a neutrophil?
A type of white blood cell that engulfs foreign matter and traps in a large vacuole called a phagosome.
What are opsonins?
Antibodies that bind to the antigen on a pathogen and then allow phagocytes to bind.
What are secondary defences?
Defences used to combat pathogens that have entered the body.
What are phagocytes?
The first line of secondary defence is phagocytosis where the phagocytes engulf and digest the pathogens.
What are macrophages?
similar to phagocytes, except they don’t fully digest the pathogen as it moves an antigen from the surface of the pathogen and attaches it to its own special protein complex, so other immune response cells can recognise the antigen.
How do antigen presenting cells help the lymphocytes?
As there may be only one Tand one B cell which is specific to the pathogen, so the chances of meeting the pathogen are small.
Therefore these antigen presenting cells may increase the chances the antigen will come in contact with them
What do T helper cells do?
T helper cells release cytokines that activate specific T and B lymphocytes which would be made complimentary to the pathogens antigens.
What are the four types of T lymphocytes?
- T helper cells
- T killer cells
- T memory cells
- T regulator cells
What do T killer cells do?
Attack and kill cells which display foreign antigens
What do T memory cells?
Provide long term immunity, as they circulate around in the blood
What are T regulator cells?
They shut down the immune respone after the pathogen has been successfully removed. They are also involved in preventing autoimmunity
What are the different types of B lymphocytes?
- plasma cells
- b memory cells
What is the difference between plasma cells and b memory cells?
Plasma cells circulate in the blood releasing antibodies.
B memory cells remain in the body for years and help for a quicker immune response second time round.
What do monokines do?
Monokines is a chemical released by macrophages that either:
-Attract or neutrophils
or
-stimulate b cells to differentiate and release anybodies.