immune system

• skin: dermis and epidermis - mucous membrane

protects the non-skin covered area • cells produce and secrete a lining of sticky mucous witch traps pathogens and prevents infection • often found with cilia

• prothrombin • fibrogen they block cuts at the site of injury to prevent entry of pathogens and continous bleeding

• damaged blood cells release chemicals that stimulate platelets to group at that area • platelets and damaged tissue release clotting factor • clotting factor chemicals convert prothrombin into thrombin (an active enzyme) • thrombin catalyzes conversion of soluble fibrogin into insoluble fibrin/fibrin

when a pathogen enters the body; • primary immune response; first encounter with particular pathogen • secondary immune respose; quicker and more intense; immunity (not the first encounter)

white blood cells are called leucocytes • macrophage; can change cellular shape to surround invading cell by phagocytosis • NO REAL IMMUNITY AS ITS RANDOM • • macrophage encounters cells and determines whether it is a natural ‘self cell’ or a ‘not self cell’ • macrophage engulfs ‘not self cell’ and lyosomes chemically digest them

a plasma white blood cell that produces antibodies by recognizing specific bacteria by their antigen -each lymphocyte is specific to a pathogen antibodies; y-shaped protein moleucles produced in response to a specific pathogen; has a binding site to attach to the bacteria antigen

• a specific antigen type is identified • a specific plasma cell is identified that can produce an antibody to bind to the antigen • the specific plasma cell clones itself to increase amount • army of plasma cells being antibody production • antibodies find their antigen match and eliminate the pathogen • some plasma cells remain in bloodstream and provide immunity incase of a second infection • these ‘memory cells’ respond quickly if the same antigen is encountered again by self-replicating (SECONDARY IMMUNE RESPONSE)

human immunodeficiency virus • infects lymphocytes and therefore causes drop in them and their antibody production • it becomes aids (acquired immune deficiency syndrome) when person loses immune response capability transmitted by; • unprotected sex • unclean needles • pregnancy, labour, delivery and breastfeeding • blood transfusion

combat bacterial infections by blocking bacteria’s metabolisms or processes (e.g.g cell wall production) • no effect on virsues; only target prokaryotic effect with not effect on eukaryotic cells

• bacteria divide quickly therefore can quickly mutate • genetic variation • resistant bacteria can rapidly repopulate colonies • longterm and overuse of antibiotics • in response, variations of antibiotics exist