The Immune Response

• Some physical defences for the immune system are; Skin, cillia, stomach acid, mucus, platelet clotting, tears and eyelashes.
• The first stage of the immune response is inflamation where mast cells activate.
• The second stage of the immune response is phagocytosis, this is where the phagocyte engulfs the pathogen and digests it using lysosomes.
• Neutrophils (a type of white blood cell) defend the body against disease. Their flexible shape allows them to engulf foregin particles or pathogens. The lysosomes in their cytoplascytoplasm contain digestive enzymes to break down the engulfed particles.
• A phagocyte is a type of white blood cell that carried out phagocytosis. They're found in the blood and in tissues and carry out non-specific immune response.
• Histamines are released during inflamation; They increase capillary permability and vasodilation, so more tissue fluid (with neutrophils and macrophages) is released.
• Histamines increase vasodialation which causes redness and pain, making the skin hot to the touch.
• Histaminse increase capillary permeability so more white blood cells are released with tissue fluid, causing swelling.
• Macrophages have a round nucleus, lysosomes and can turn into and antigen presenting cell using MHC.
• During Phagocytosis a white blood cell engulfs a pathogen and digests it using lysosomes.
• When a lysosome and a pathogen are moved into the same vesicle it is called a phagolysosome.
• Once a pathogen has been digested the macrophage turns into and antigen presenting cell.