communicable diseases

Cards (25)

  • pathogens are microorganisms that enter the body and cause disease
  • pathogens cause communicable diseases - diseases that are easily spread
  • both plants and animals can be infected by pathogens
  • pathogens can be bacteria, viruses, protists or fungi
  • bacteria are very small living cells
  • bacteria are very small cells - about 1/100th the size of your body cells
  • bacteria cells can reproduce rapidly inside your body
  • bacteria cells can make you feel ill by producing toxins that damage your cells and tissues
  • viruses are not cells
  • viruses are tiny - about 1/100th the size of bacteria cells
  • viruses reproduce rapidly inside the body
  • viruses live inside your cells and replicate themselves using the cells machinery to produce many copies of themselves - the cell will then burst, releasing all the new viruses, this cell damage is what makes you feel ill
  • protists are single celled eukaryotes
  • some protists are parasites
  • parasites live on or inside other organisms and can cause them damage
  • parasites are often transferred to the organism by a vector, which doesn't get the disease itself
  • some fungi are single-celled
  • other fungi have a body which is made up of hyphae
  • hyphae is thread like structures
  • hyphae can grow and penetrate human skin and the surface of plants, causing diseases
  • the hyphae can produce spores, which can be spread to other plants and animals
  • pathogens can be spread in different ways: water, air, direct contact
  • water: some pathogens can be picked up by drinking or bathing in dirty water
  • air: pathogens can be carried in the air and can then be breathed in - some airborne pathogens are carried in the air in droplets produced when you sneeze or cough
  • direct contact: some pathogens can be picked up by touching contaminated surfaces - when touching the same surface as an infected person