Non-Specific Defence Systems

• Non-specific defence system

  The body's first line of defence against pathogens, preventing them from entering the body
• Parts of the non-specific defence system

  • Skin
  • Nose and mucus
  • Cilia in trachea and bronchi
  • Stomach acid
• Skin


  • Protective layer covering the body
  • Outer layer of dead cells difficult for pathogens to penetrate
  • Produces sebum to kill bacteria
  • Can scab over when damaged
• Nose and mucus

  • Contract pathogens before they enter the breathing system
• Cilia in trachea and bronchi

  • Covered in mucus
  • Contract pathogens upwards towards the throat to be swallowed
• Stomach acid


  • Kills pathogens before they can enter the digestive system further
• Even with the nonspecific defense systems, pathogens can still get into the human body and cause serious disease, so the immune system also protects us