Specific Immunity 2 Flashcards
What are lymphocytes and what are types
Lymphocytes are white blood cells that defend against specific diseases, 2 main types B and T cells.
What are memory cells for and what is difference between B and T cells.
Memory cells provide long term immunity
Difference is B cells provide Longer term than T memory cells
What is T memory cell
T memory cell remains in body for months so if an individual is exposed to same antigen, they can respond quicker
What is neutralisation
Neutralisation is when antibodies bind to pathogens’ receptors which means they cannot infect body cells.
What is a leucocyte
Leucocyte is a white blood cell.
How does a cell become an APC
Cell becomes APC when pathogen binds to B cell receptor.
Cell forms projections around bacterium and engulfs it. Vacuole forms. Lysosomes fuse with vacuole, bacterium digested by hydrolysis enzymes. Vacuole fuses with cell membrane, releasing digestive enzymes and presenting antigen
What are roles of antigen presentation
Roles of antigen presentation are:
Antigens retained so other B/T cells that encounter antigen can go through clonal expansion and selection.
Kills bacteria in process
What is clonal selection
Clonal selection is when T or B cells encounter and bind to pathogen
What is clonal expansion
Clonal expansion is when B or T cells multiply by mitosis
How do memory cells provide long term immunity
B and T Memory cells provide long term immunity through secondary immune response. They remain in blood and on reinfection with same antigen, memory cells are cloned and antibodies are released from plasma cells
What is dis adv of T cells killing infected human cells
Dis adv of T cells killing infected human cells are:
Loss of cells could damage functioning of organs
How does killing virus infected cells help control infection
Killing virus infected cells helps control infection by:
Cells killed before virus replication cycle complete
Reduces production of viruses so there are fewer viruses to infect new cells
How do macrophages present antigens to T helper cells
Macrophages present antigens to T helper cells by!
Macrophage binding to T helper cell, CD4 receptor binds to macrophage forming MHC
