Flashcards in Key Area 4.2: Specific Cellular Defences Deck (17):
What are body tissues monitored by?
A range of white blood cells that constantly circulate and provide immune survaliance.
What happens if tissues are damaged or invaded?
Certain cells release cytokines, which increase blood flow to the site of damage and invasion.
What does increase blood flow at the site of infection or damage lead to?
Accumulation of specific white blood cells.
What does each lymphocyte have?
A single type of meme brand receptor specific to one type of antigen.
What does a lymphocyte do?
Responds to antigens on pathogen cells, infected cells or toxins released by pathogens.
What happens when a lymphocyte binds to an antigen?
Repeated lymphocyte division which produces a clone of identical lymphocyte cells.
What are the two broad categories of lymphocyte?
T lymphocytes and B lymphocytes.
What is clonal selection theory?
The selection of lymphocytes by antigens and their response in producing a clone.
What do T lymphocytes have?
Specific surface proteins that allow them to disturb guide between the surface molecules of the body’s own cells and cells with foreign molecules on their surfaces
What do T lymphocytes do in autoimmunity?
Respond to the body’s own cell surface antigens and produce auto immune disease.
What can T lymphocytes do?
- One group can release cytokines which activate B lymphocytes and phagocytes. Phagocytes that engulf pathogens display fragments of the pathogens antigens on their surfaces.
- One group destroy infected cells by inducing apoptosis.
What do antigen resenting cells active?
T lymphocytes which move to the site of infection guided by the presence of cytokines in the area.
What do B lymphocytes clone do?
Produce specific antibody molecules which recognise specific antigens on the surface of a pathogen or a toxin.
What do B lymphocytes activated by antigen presenting cells and stimulated by T lymphocytes produce?
A clone of B lymphocytes which secrete antibodies into the blood and lymph to transport them to infection sites.
What role do B lymphocytes play in allergies.
Response to an antigen that is normally harmless.
What do some T and B lymphocytes produced by clonal selection survive as?