communicable diseases

• Pathogens


  Microorganisms that enter the body and cause disease
• Pathogens


  • They cause communicable (infectious) diseases
  • Both plants and animals can be infected by pathogens
• Bacteria


  Very small living cells that can reproduce rapidly inside your body and produce toxins that damage cells and tissues
• Viruses


  Tiny, not cells, live inside your cells and replicate using the cells' machinery, then the cell bursts releasing new viruses, causing cell damage
• Protists


  Single-celled eukaryotes, some are parasites that live on or inside other organisms and can be transferred by a vector
• Fungi


  • Some are single-celled, others have a body made up of hyphae that can grow and penetrate human skin and plant surfaces, causing disease, and produce spores that can spread
• Ways pathogens can be spread

  • Water
  • Air
  • Direct contact
• How viruses cause cell damage

  1. Viruses live inside cells and replicate using the cells' machinery

  2. The cell then bursts, releasing new viruses