infection and response -

Question 1

what features does the body have to to stop pathogens getting in
5 points

Answer 1

1) the skin acts as a barrier, it also secretes antimicrobial substances which kill pathogens
2) hairs and mucus in your nose trap particles that could contain pathogens
3) the trachea and bronchi secrete mucus to trap pathogens
4) the trachea and bronchi are lined with cilia, these hair-like structures, which waft the mucus up to the back of the throat where it can be swallowed
5) the stomach produces hydrochloric acid, this kills pathogens that make it that far from the mouth

Question 2

what are the ways white blood cells defend against pathogens inside the body
3 points

Answer 2

1) phagocytosis
2) producing antibodies
3) producing antitoxins

Question 3

what is phagocytosis

Answer 3

where white blood cells engulf foreign cells and digest them

Question 4

what do antibodies do

Answer 4

1) every invading pathogen has unique molecules called antigens on its surface
2) when some types of WBC come across a foreign antigen the will start to produce proteins called antibodies
3) these will lock onto the invading cells so that they can be found and destroyed by other WBC
4) the antibodies produced are specific to that type of antigen
5) antibodies are then produced rapidly and carried around the body to find similar pathogens
6) if a person is infected with the same pathogen again the WBC will rapidly produce the antibodies to kill it

Question 5

what do antitoxins do

Answer 5

these counteract the toxins produced by the invading bacteria