Human Defence System

Question 1

How does the skin prevent pathogens entering your body?

Answer 1

• acts as a physical barrier
• produces antimicrobial secretions to kill pathogens

Question 2

How does the nose prevent pathogens entering your body?

Answer 2

• has hairs and mucus which prevents particles from entering your lungs

Question 3

How does the trachea and bronchi prevent pathogens entering your body?

Answer 3

• secrete mucus in order to trap pathogens
• cilia (hair-like structures) waft mucus upwards so it can be swallowed

Question 4

How does the stomach prevent pathogens entering your body?

Answer 4

• produced hydrochloric acid that kills any pathogens

Question 5

How do white blood cells protect you?

Answer 5

consuming pathogens - destroys them, meaning they can no longer make you feel ill

producing antibodies - if the individual has already been infected by the pathogen, they produce antibodies at a faster rate and the individual will not feel symptoms of illness - immune

producing antitoxins - they neutralise toxins released by the pathogen by binding to them