Neutrophils - produced in the bone marrow -innate and secrete cytokines to attract phagocytes. Multilobed nucleus and grainy.
Macrophages - produced in the bone marrow - innate
Monocytes - Kidney shaped nucleus
Lymphocytes
Have large nucleuses and smaller than phagocytes.
T cells - Mature in the thymus gland. Helper, Killer, Regulatory, Memory. Cell mediated immune response.
B cells - Mature in bone marrow. Plasma and Memory. Humoral immune response.
Phagocytosis - non specific
Chemicals attract the phagocyte to the pathogen.
Phagocytes recognises the pathogen as a 'non-self' cell
Phagocyte engulfs the pathogen by endocytosis and is surrounded by a vacule - Phagosome.
Phagosome combines with lysosome containing digestive enzymes forming a phagolysosome.
Digestive enzymes break down the pathogen and waste is removed by exocytosis.
Phagocytosis - Specific
Phagocytosis is done by a macrophage
Antigens from the broken down pathogen bind to maceophage antigens forming a - Histocompatibility complex (MHC)
Display antigens on the plasma membrane and becomes an APC - Antigenpresenting cell.
Specific immune response
Antigen from pathogen or APC are present
Detected by
T lymphocytes - cell mediated
B lymphocytes - humoral
Cell mediated response
APC has antigens complemetry to receptor on t helper cell which stimulates the immune response - Colonal selection
Cloning by mitosis of the T cell and then differentiation into different t cells. - T helper, T regulator, T killer cells. - Colonal expansion and differentiation.
Humoral response
In response to pathogens
Activated T helper cells bind to pathogen receptors on b cells - colonal selection
Activated T cell release interleukins which activate other b cells.
B cells rapidly divide by mitosis into - B plasma cells and B memory cells. - Colonal expansion.
Plasma cells produce specific and complementary antibodies which bind to the antigens, disabling them.
Secondary response
If the body is infected by the same pathogen again B memory cells rapidly divide into B plasma cells
Much faster response as primary response is skipped.