U.3 K.A-6 Specific Cellular Defences Against Pathogens Flashcards
Is the third line of defence described as non-specific or specific?
Specific
Which group of cells in the immune system bring about a specific immune response?
- T lymphocytes
- B lymphocytes
All lymphocytes originate in the bone marrow. If they pass to the thymus to complete development, what do they become?
T lymphocytes
If lymphocytes complete all their development in the bone marrow, what type of lymphocyte do they become?
B lymphocytes
What name is given to any foreign molecule that is able to elicit a specific immune response from a lymphocyte?
Antigen
Give some examples of antigens.
- Viruses
- Bacteria
- Cancer cells
- Molecules on the surface of transplanted cells
There are a number of different lymphocytes. What is found on the surface of every lymphocyte that makes each lymphocyte different?
A different antigen receptor
What is each antigen receptor on the surface of each lymphocyte specific to?
One type of antigen
Whenever an antigen attaches to the specific antigen receptors on a lymphocyte, the lymphocyte is activated and responds by dividing repeatedly to form identical lymphocytes. What is this called?
A clonal population
Whenever an antigen enters the body, the B lymphocytes respond by producing what?
Antibodies
What shape is an antibody?
Y-shaped
What is found at the end of each arm of the Y-shaped antibody?
A receptor specific to a particular antigen
When a B lymphocyte becomes activated by the presence of an antigen, it responds by making a clone of B lymphocytes which all make antibody. What other cells are made to produce antibodies of the same type again in the future?
Memory B cells
What name is given to the combination formed when the antibody binds to the foreign antigen?
Antigen-antibody complex
The antigen-antibody complex renders a pathogen inactive. What cells come along and destroy the pathogen(disease causing foreign molecule) by phagocytosis?
Phagocytes