Immune system and defences

Question 1

How does the skin stop pathogens?

Answer 1

• Prevents microorganisms from entering the body
• Secretes antimicrobial substances and oils that kill pathogens

Question 2

How does mucus stop pathogens

Answer 2

• The nose and trachea / bronchi are lined with mucus that trap pathogens

Question 3

How does cilia stop pathogens?

Answer 3

• Lines the trachea and bronchi
• Waft mucus up to the back of the throat to be swallowed into the stomach

Question 4

How does stomach acid stop pathogens?

Answer 4

• The stomach has hydrochloric acid to kill any pathogens

Question 5

How does phagocytosis kill pathogens?

Answer 5

• Certain white blood cells (phagoytes) bind to and engluf certain pathogens. This kills the pathogen

Question 6

How do antitoxins help stop pathogens?

Answer 6

• Bind to and neutralise harmful toxins created by pathogens

Question 7

How do antibodies kill pathogens

Answer 7

• Bind to foreign antigens and rapidly produces antibodies to track and kill the pathogen
• If we encounter the pathogen again, the body will remember the antibody and rapidly produce them again. This means that we are immune