digestive system

• what is the role of the large intestines?

  Absorption of water
• what is the role of the small intestines?


  Absorption of small food molecules
• how does the skin prevent pathogens from entering?

  provides protective layers and has many layers of dead cells which makes pathogens hard to penetrate
• how does the trachea prevent pathogens from entering?

  contains mucus which traps microorganisms which can be destroyed by WBC called phagocytes
• what does the mucus contain?

  the enzyme lysozyme which kills bacteria by digesting bacteria cell wall
• where else is lysozyme found?

  in tears which helps prevent pathogens from entering the eyes
• how does the stomach prevent pathogens entering?

  contains HCL acid which kills bacteria in food or water
• how do expulsive reflexes work?

  where body tries to expel pathogens by coughing sneezing vomiting or diarrhoae
• how can pathogens enter through the skin?

  if the skin is damaged so the body tries to seal the damaged area with blood clots before lots of pathogens enter