Injection and response

• A communicable disease is a disease that can be spread from person to person.
• A communicable disease is caused by pathogens; including viruses, bacteria, protists, and fungi
• A pathogen is a micro-organism that causes diseases
• Bacteria and viruses reproduce rapidly inside the body
• Bacteria may produce poisons (toxins) that damage tissues and make us feel ill
• Viruses live and reproduce inside cells, causing cell damage
• Communicable diseases: chicken pox, measles, HIV, common cold

  Non-communicable diseases: Lung cancer, arthritis, diabetes, coronary heart disease
• Natural defence mechanisms: hairs in our nose, stomach acid, skin, scabs, trachea cilia, tears and eyelashes
• Hairs in our nose protects us because the hair stops large particles in a sticky layer of mucus
• Stomach acid helps protect us because it is coated with a special lining to prevent the acid corroding the wall away
• Skin helps protect you because it has layers of skin that block microorganisms from entering
• Scabs help protect you because they are formed with a blood clot and stops bacteria getting in
• Trachea cilia protect us because there are layers or mucus traps microorganisms and particles
• Tears and eyelashes protects us because the tears kill bacteria on the surface or the eye. Your eyelashes protect your eye and work as a barrier
• Transmission vectors (how diseases are spread) are food, physical/ direct contact, through water, animal vectors, exchange bodily fluids, air
• Vaccinations:

  1. A dead or weakened pathogen from a vaccine enters the body
  2. The pathogen has antigens that the body recognises as foreign
  3. The white blood cells of the immune system create antibodies which destroy the pathogen
  4. The same pathogen tries to infect the person again
  5. The immune system remembers how to make the right antibodies, and the pathogen is killed more quickly
  6. The person is now immune to the pathogen
• Passive immunity is when someone is given the antibodies to kill the disease
• Active immunity is when the body creates its own antibodies
• Herd immunity is when vaccinated people protect the people who cannot get vaccinated, are immune supressed, are pregnant, have cancer or have allergies
• You can tell your plant is ill because it will have stunted growth, malformed leaves or stem, decay of areas, growth or bumps, coloured or dead spots on leaves, area of rot or decay, lots of pests
• Plants need magnesium to make chlorophyll
• When a plant doesn't have any magnesium the green in the leaves start to leave the leaf
• Drugs and their origin:

  • Willow tree bark - Aspirin
  • Poppies - Heroin
  • Fruit and veg - Alcohol
  • Foxgloves - Heart drugs
  • Nicotiana tabacum plant - tobacco
  • Bull's testicles - body-building steroids
  • Penicillium mould - penicillin