Infection and Responce

• Pathogens are microorganisms that cause communicable diseases
• Pathogens can be spread through

  Droplets , vectors , water , food , direct contact
• Viruses reproduce rapidly , which causes damage to cells
• Bacteria can produce toxins that damage tissue
• Fungi penetrate human skin and surface of plants
• Protists are single celled organisms that are eukaryotic
• HIV can be transmitted in blood when drug users share needles
• Skin is a non-specific barrier that prevents pathogens from entering the body
• The nose has hairs and mucus that trap pathogens before they reach lung
• eyes secrete tears that have enzymes that destroy pathogens
• the trachea is lined with cells that have tiny hairs called cilia that move mucus and pathogens upwards towards the throat
• cilia reduces the amount of pathogens entering your lungs
• goblet cells produce mucus that act as a physical barrier that traps pathogens
• goblet cells are found in the trachea
• The stomach contains hydrochloric acid that kills bacteria
• physical barriers 


  skin , nose , trachea and bronchi
• Cells in the body are covered in antigens
• Lymphocytes recognise proteins on the surface of pathogens called antigens
• Lymphocytes detect foreign substances on the cells and can produce antibodies
• Lymphocytes can also call over phagocytes which can destroy them by phagocytosis: engulfing and digesting.
• Phagocytes surround any pathogens in the blood and engulf them
• Vaccinations expose us to the antigens of a pathogen so we can develop immunity to it
• Vaccinations contain small quantities of dead, weakened or inactive forms of pathogen
• Malaria is spread by mosquitos
• Malaria Symptoms 


  re-occurring fever that can be fatal
• Malaria Preventions

  killing mosquitos, mosquito net, vaccination
• Aspirin originates from the bark of willow trees
• Digitalis originates from foxgloves
• Penicillin was discovered by Fleming from Penicillium mould
• Efficiency is how well the drug works
• Toxicity is how harmful the drug is
• Dosage is how much of the drug should be given
• Stage 1 of drug testing is too test the drug on human cells and tissues
• Stage two of drug testing is to test it on live animals as our bodies are similar to theirs
• Stage 3A of drug testing is to test the drug on healthy volunteers to find the maximum dosage before side effects occcur
• Stage 3B of drug testing is to give the drug to people suffering from the illness to discover the optimum dosage
• In a double-trail test neither the doctor or the patient know who has taken the drug - only the researcher
• A placebo is a substance or treatment that contains no active drug
• its important for medical trails to be double blind as it avoids any bias by the patients or/and the doctors