immune system and defences

• What type of cell helps to defend against pathogens and are part of the immune system

  White blood cells
• How do the trachea and Bronchi act as a defence against pathogens?

  some of the cells that line the trachea and Bronchi produce mucus which traps pathogens
• What do other cells have as a defence against pathogens?

  tiny hair-like projections called 'cilla' to help move the mucus and pathogens out of the lungs
• How does the stomach act as a defence against pathogens?

  it produces hydrochloric acid, which creates a very low pH that destroys pathogens
• name 4 non-specific defences that prevent pathogens from entering the body

  . Skin (and the oil it secretes), stomach acid, hair and mucus in airways, tears in eyes
• How does the skin act as a defence against pathogens?

  covers the body physically preventing pathogens from entering, secretes oils and antimicrobial substances that kill pathogens
• What is the difference between non-specific and specific defences against pathogens?

  Non-specific defences work against any type of pathogen, specific defences are specific to a particular pathogen
• what is the role of the immune system?

  locate and destroy pathogens that enter the body
• How does secreting oils make it harder for pathogens to get through?

  This is because some of the components in the oils have antimicrobial properties, which means they can kill or inhibit the growth of these pathogens.
• What is a pathogen?

  A microorganism that can cause disease
• What do physical and chemical barriers do?

  stop pathogens from getting in
• How does the nose act as a defence against pathogens?

  by having lots of mucus which can trap pathogens
• What enzyme is found in tears?


  Lysozyme