4.1.1 Communicable Disease and Prevention – T lymphocytes Flashcards
(11 cards)
Where are T lymphocytes produced and where do they mature?
- Produced in the bone marrow.
- Mature in the thymus.
Give 4 examples of antigen presenting cells
- Macrophages after ingesting a pathogen.
- Host cells infected by a virus.
- Cancer cells.
- Transplanted cells.
What type of immunity are T lymphocytes involved in?
Cell mediated immunity.
Describe how clonal selection activates a specific T lymphocyte.
A specifically shaped receptor on the T lymphocytes will bind to a complementary antigen on an antigen presenting cell.
What is the name of the process by which activated T lymphocytes divide by mitosis?
Clonal expansion.
List the 4 types of T lymphocytes that are produced during clonal expansion.
T killer cells (cytotoxic cells)
T helper cells
T regulator cells
T memory cells
Describe how T killer cells kill infected cells.
T killer cells bind to infected cells and secrete enzymes and perforins (e.g. hydrogen peroxide), which perforate the plasma membrane of infected cells.
Name the chemical that T helper cells release.
They release cytokines called interleukin.
What is the function of the interleukin that is released by T helper cells?
- Stimulate the activation of T killer cells.
- Stimulate macrophages to carry out phagocytosis.
- Stimulate B cells to differentiate into plasma cells and produce antibodies.
What is the function of the T regulator cells in the immune response?
They switch off the immune response once the pathogen has been removed.
What is the function of T memory cells in the immune response?
They remain in the body and are involved in producing a faster secondary response if there is a re-infection of the same pathogen.
