Chapter 7.3 Specific Defences Against Disease

Question 1

What is a specific defence and an example

Answer 1

Defence of the body that is directed against a specific pathogen
For example if you get infected with chickenpox virus, the body will make antibodies to combat that virus and those antibodies are only effective against chicken pox virus and will not work against any other virus or bacterium

Question 2

What makes up the immune system?

Answer 2

-The immune system is made up of different types of cells that are found in most organs of the body.
-These cells help protect the body by detecting and attacking foreign organisms, harmful chemicals and abnormal cells

Question 3

What is the immune response?

Answer 3

A response triggered by foreign substances or micro-organisms entering the body

Question 4

What are two examples of specific immune system cells?

Answer 4

B-cells and T-cells

Question 5

What type of cell are B-cells and T-cells?

Answer 5

White blood cells called lymphocytes

Question 6

Where are B-cells and T-cells produced from and where do they end up once produced?

Answer 6

-They are both produced from bone marrow and end up in the lymphoid tissue
-However they mature by different routes.
-About half the cells produced by the bone marrow go to the thymus, were they mature into T-cells before being incorporated into the lymphoid tissues.

Question 7

What are the key cells involved in the immune response?

Answer 7

B-cells and T-cells

Question 8

Where can lymphatic tissue be found in the body?

Answer 8

-Adenoids
-Tonsils
-Thoracic duct
-Right lymph duct
-Right and left subclavian vein
-Thymus
-Lymph nodes in armpits and upper thigh
-Spleen

Question 9

What are antigens?

Answer 9

Any substance capable of causing the formation of antibodies when introduced into the tissues.

Question 10

What can antigens include?

Answer 10

Antigens are large molecules e.g. proteins, carbohydrates, lipids or nucleic acid and may include (among others):
-Virus partciles
-Whole micro-organisms e.g bacterial cell
-Part of a bacterium e.g. flagella, cell wall or capsule
-Toxins
-Molecules on cells e.g. blood cells
-Pollen grains
-Egg whites

Question 11

What are self-antigens?

Answer 11

Any large molecule produced in a person’s own body; dose not cause an immune response in that person.

Question 12

What are non-self antigens?

Answer 12

Any compound foreign to the body that triggers an immune response

Question 13

At what stage of life does the immune system become ‘programmed’?

Answer 13

Before birth so it can distinguish self-antigens and non-self antigens and from then on, it only attacks non-self antigens.

Question 14

What is an antibody?

Answer 14

A substance produced in response to a specific antigen