Specific immune response Flashcards
Describe activation of B cells
Antigens on bacterium binds to antigen receptor on B cell
B cell becomes APC
Activated T helper cell with complementary receptors bind to the APC producing cytokines
Cytokines stimulate B cell to divide by mitosis
B effector cells and B memory cells produced
B effector cells differentiate into plasma cells which secrete antibodies which bind to antigens that stimulated the immune response
Antibodies bind to antigen on bacterium and labels them for easier destruction by macrophages
Describe activation of T helper cells
Bacterium with antigens are engulfed by macrophages
Macrophage presents antigens on its surface to become an APC
APC binds with a T helper cell with complementary receptors
T helper cell is activated and divides by mitosis
Memory cells produced
Describe activation of T killer cells
A cell which is infected with pathogens becomes an APC by presenting antigens
T Killer cell with complementary receptors bind to APC
Cytokines from T helper cells stimulate division and T killer cell is activated
Binds to infected cells presenting antigens
T killer cell released chemicals causing pores to form in the infected cell causing lysis so infected cell dies
Describe primary immune response
following the first exposure to a foreign antigen
slow response - alag phase occurs when no antibodies are produced but activated B cells are differentiating into plasma cells
Describe secondary immune reponse
Occurs if infected by same bacterium/virus the system responds faster
involved memory cells
causes immunity
B cells - differentiate immediately to release antibodies so greater production
What is a lymphocyte?
WBC that defends the body against disease and circulate the blood
Define antigen
recognised as non self and stimulate immune response
Define antibody
special protein molecules that acts as labels allowing phagocytes to recognise and destroy the cell
Whats an APC?
carry antigen from a bacteria
