human defences

• nose is full of hairs that produce mucus and trap particles
• trachea and bronchi secrete mucus and are lined with cilia which move mucus up to the back of the throat where it is swallowed
• stomach produces acid which destroys microorganisms that enter
• what is phagocytosis


  • phagocytes surround any pathogens in the blood and engulf them
  • enzymes in the phagocyte break down the pathogen and destroy it
• some white blood cells produce antibodies which seek out the antigen of a pathogen and attach to it to kill it.
• some white blood cels produce antitoxins that counteract the toxins produced by pathogens