human defence systems

Question 1

what is a physical and chemical barrier?

Answer 1

skin

Question 2

what does the skin contain?

Answer 2

secretes oils and has antimicrobial substances - kill pathogens

Question 3

how are our noses adapted to stop pathogens entering?

Answer 3

little hairs, mucus

Question 4

what happens if they get through the nose?

Answer 4

go through trachea or Ophiuchus

Question 5

what happens if they head for lungs via trachea?

Answer 5

trachea, bronchi and bronchials are covered in mucus - lined with cilia - move mucus to back of throat - swallow - stomach

Question 6

what acid does our stomach produce and why?

Answer 6

hydrochloric acid - kills pathogens

Question 7

what is the most important part of the immune system?

Answer 7

white blood cells

Question 8

what is phagotisosis?

Answer 8

white blood cells engulf pathogens

Question 9

how do the white blood cells do this?

Answer 9

track down pathogens, bind to them and then engulfing them - destroying them

Question 10

Why do white blood cells produce antitoxins?

Answer 10

when the pathogens produce toxins white blood cells produce antitoxins

Question 11

why do white blood cells produce antibodies?

Answer 11

the antigens - substances immune system detects as foreign and antibodies lock onto them which tells white blood cells to destroy them - each antibody is specific to antigen - produces loads - remembers