3.6 Specific Cellular Defences Against Pathogens Flashcards
What are lymphocytes?
White blood cells involves in the sepcific immune response
What are the two types of lymphocytes?
- B-lymphocytes
- T-lymphocytes
Where are lymphocytes made?
In the bone marrow from stem cells
Where do T-lymphocytes mature?
Thymus Gland
Where do B-lymphocytes mature?
Bone Marrow
What does each lymphocyte have?
A different membrane receptor which is specific for one antigen
What happens when a lymphocyte binds to its particular antigen on the surface of a pathogen?
The lymphocyte becomes active
What happens to the active lymphocyte?
It dissolves repeatedly to produce a clonal population of identical lymphocytes which are specific to the particular pathogen which activated it
What can activated B-lymphocytes produce?
A protein specific to an antigen called antibodies
What are antibodies able to bind to?
The antigen creating an antigen-antibody complex
What does the binding of the antibodies cause?
- Inactivation of the pathogen
- Pathogen to become more susceptible to phagocytosis
What do B-lymphocytes over react to?
Harmless substance like dust, pollen and penicillin
What do B-lymphocytes release?
Antibodies which cause mast cells to release histamine
What can some allergic reactions trigger?
Anaphylactic shock
How do T-lymphocytes destroy infected cells?
By recognising antigens of the pathogen on the cell membrane and including apoptosis
What is apoptosis?
Programmed cell death
How are self-destructive enzymes produced?
The T-lymphocyte inserts a protein into the infected cell
What do self-destructive enzymes do?
Destroy the infected cells
What is autoimmunity?
A condition where T-lymphocytes attack the bodys own cells
What are examples of autoimmune diseases?
Type 1 diabetes, multiple sclerosis and rheumatoid arthiritis
What is the primary response?
A pathogen infects the body and gives raise to an immune respobse and select the correct T and B lymphocytes and produce antibodies
What happens if a foregin antigen is recognised by memory cells?
They very rapidly divide and form many clones of both T-lymphocytes and antibody-producing B-lymphocytes
What does HIV do?
Attacks and destroys T-lymphocytes that leads to AIDS
What does it mean if someone has AIDs?
They have a damaged immune system and so are more vulnerable to infections
