Human Defence System

Question 1

How does your body protect against pathogens?

Answer 1

-Nose
-Stomach
-Trachea/bronchi
-Skin

Question 2

How does your nose protect against pathogens?

Answer 2

Hair and mucus in your nose trap particles

Question 3

How does your stomach protect against pathogens?

Answer 3

Stomach contains hydrochloric acid to kill any pathogens that enter the body via mouth

Question 4

How does your trachea and bronchi protect against pathogens?

Answer 4

-Cilia which move back and forward to transport the mucus towards the throat
-Mucus to trap pathogens

Question 5

How does your skin protect against pathogens?

Answer 5

Skin acts as a barrier to pathogens

Question 6

What needs to happen if a pathogen overcomes the natural barriers?

Answer 6

They need to be neutralised or destroyed

Question 7

What are 2 types of white blood cells?

Answer 7

-Phagocytes
-Lymphocytes

Question 8

What do the phagocytes do?

Answer 8

The phagocyte (or white blood cell) engulf the pathogen and digest them, in a process called phagocytosis

Question 9

What do lymphocytes do?

Answer 9

-They produce antitoxins to neutralise the toxins
-They also produce antibodies.

Question 10

What do antibodies do?

Answer 10

Pathogens have antigens on their surface, antibodies produced by white blood cells (or lymphocytes) lock onto the antigen on the outside of the pathogen, the white blood cell can then destroy the pathogen.

Question 11

What are antibodies specific to?

Answer 11

Antibodies are specific to one antigen and will only work on that pathogen.