Non-Specific Defence Systems

• What are some diseases caused by pathogens?

  Salmonella, HIV, malaria, measles
• What are the two main defense systems against pathogens in the human body?

  • Nonspecific defense system
  • Immune system
• What is the primary job of the nonspecific defense system?

  To prevent pathogens from entering the body
• What are the four main parts of the nonspecific defense system?

  1. Skin
  2. Nose
  3. Trachea and bronchi
  4. Stomach
• What does the skin form to protect the body?

  A protective layer covering the body
• What is the outer layer of the skin made of?

  Dead cells
• What oily substance does the skin produce to kill bacteria?

  Sebum
• What happens when the skin is damaged?

  The skin scabs over to prevent entry
• What are two examples of body parts not covered by skin?

  Nostrils and mouth
• How does the nose help protect the body from pathogens?

  It contains hair and mucus to trap pathogens
• What are the tiny hairs in the trachea and bronchi called?

  Cilia
• What do cilia do in the respiratory system?

  They trap pathogens and move mucus upwards
• Where does the mucus go after being moved by cilia?

  It is swallowed into the stomach
• Why is hydrochloric acid important in the stomach?

  It kills pathogens before digestion
• Can pathogens still enter the body despite nonspecific defenses?

  Yes, they can cause serious disease