Defence Mechanisms

Question 1

What is the role of the second line of defence?

Answer 1

It is non-specific, and helps to eliminate wide variety of microorganisms which have entered the body. Ways of doing this is through Phagocytosis, inflammation, fever and antimicrobial substances.

Question 2

What is the role of the third line of defence?

Answer 2

It is specific, therefore helps to eliminate specific microbes which have entered the body and protect the host agains future attack by the same organism. They are called acquired because the develop as a result of contact with the microbe.

Question 3

What is inflammation?

Answer 3

Inflammation is the body’s immune response to damaged tissue.
This damage may be caused by- microbial infection, cuts and abrasions, burns, chemicals, and allergies

Question 4

What are the signs of inflammation?

Answer 4

1. Redness
2. Heat
3. Swelling
4. Pain
5. Loss of function

Question 5

What are the Functions of inflammation?

Answer 5

1. Destroys the microbes
2. Prevents the spread of microbes by building a wall of fibrin around it so it is confined to a local area
3. Clears the site of cellular debris
4. Repairs the damaged tissue.

Question 6

What are natural killer cells?

Answer 6

They are found in the blood, lymph nodes and spleen.

They recognise the self antigens on normal, healthy body cells

Question 7

What is the role of the first line of defence?

Answer 7

It is non-specific, which aims to prevent a wide range of microorganisms from entering the body.