Human Defenses

Question 1

What does the skin do to protect the body from pathogens?

Answer 1

• It acts as a barrier by covering tissues underneath.
• It produces antimicrobial secretions to kill bacteria.
• It heals quickly when cut through blood clotting.

Question 2

What defences are found in the respiratory system?

Answer 2

• Hairs and mucus which trap pathogens and dirt.
• The trachea and bronchioles also produce mucus.
• Cilia waft mucus up the throat to be swallowed.

Question 3

What does the stomach do to kill pathogens?

Answer 3

It produces acid to pathogens in mucus and food.

Question 4

What can white blood cells do to defend against pathogens?

Answer 4

• Ingest pathogens and digest and destroy them.
• Produce antibodies to destroy particular pathogens.
• Produce antitoxins to counteract the toxins produced by pathogens.