Chemical and Mechanical barriers

Question 1

state mechanical barriers

Answer 1

1. nostril hairs help trap dust carrying pathogens

2. the skin has a thick outer layer of dead skin cells containing keratin protein which is very difficult to penetrate

Question 2

state chemical barriers

Answer 2

1. mucus found in the respiratory system and alimentary canal traps pathogens. cilia sweep mucus to the throat to be swallowed
2. the stomach secretes hydrochloric acid which is a strong acid that kills bacteria in the food we eat and mucus we swallow.
3. white blood cells take in and digest these pathogens by phagocytosis while others produce antibodies that kill pathogens
4. vaccination against a particular disease helps a person produce antibodies quickly if infected by a pathogen that causes the disease