4.1.6: The specific immune response

Question 1

What are T lymphocytes and B lymphocytes?

Answer 1

White blood cells with a large nucleus and specialised receptors on their plasma membranes.

Question 2

Name the four types of cells that T- lymphocytes will differentiate into.

Answer 2

• T helper cells
• T Killer cells
• T memory cells
• T regulator cells

Question 3

What is the role of T helper cells?

Answer 3

They release cytokines (chemical messengers) that stimulate the b-cells to develop and stimulate phagocytosis by the phagocytes.

Question 4

What is the role of T killer cells?

Answer 4

They attack and kill host-body cells that display the foreign antigen.

Question 5

What is the role of T memory cells?

Answer 5

They provide long term immunity.

Question 6

What is the role of T regulator cells?

Answer 6

They shut down the specific immune response after the pathogen has been successfully removed. They are also involved in preventing autoimmunity.

Question 7

What do B lymphocytes develop into?

Answer 7

• Plasma cells.

- B memory cells.

Question 8

What is the role of plasma cells?

Answer 8

They circulate in the blood, manufacturing and releasing the antibodies.

Question 9

What is the role of B memory cells?

Answer 9

They remain in the body for a number of years and act as the immunological memory.

Question 10

Why is it important that the cells involve in the specific immune response can communicate effectively using cell signalling?

Answer 10

Because there are many types of cells involved.

Question 11

How is communication between cells achieved?

Answer 11

The release of hormone-like chemicals called cytokines.

Question 12

There is a huge number of signalling molecules, each performing a different role, what must the target cell have in order to detect the signal.

Answer 12

A cell surface receptor complimentary to the shape of the cell signalling molecule.

Question 13

How do macrophages communicate using cytokines?

Answer 13

Macrophages release monokines Some monokines attract neutrophils by chemotaxis and others stimulate B cells to differentiate and release antibodies.

Question 14

What is chemotaxis?

Answer 14

The movement of cells towards a particular chemical.

Question 15

How do T cells and macrophages communicate using cytokines?

Answer 15

They release interleukins which can simulate the clonal expansion (proliferation) and differentiation of B and T cells.

Question 16

Why do some cells release interferon?

Answer 16

It inhibits virus replication and stimulates the activity T killer cells.

Question 17

What is an autoimmune disease?

Answer 17

When the immune system attacks a part of the body

Question 18

How do they arise?

Answer 18

When antibodies start to attack our own antigens- possibly because antigens that are not normally exposed become exposed to attack.

Question 19

Give two examples of autoimmune diseases.

Answer 19

Arthritis and lupus.

Question 20

What is the cause of arthritis?

Answer 20

The cause is uncertain, but it starts with antibodies attacking the membranes around the joint.

Question 21

What is the cause of lupus and what part of the body does it affect?

Answer 21

Lupus can affect any part of the body, causing swelling and pain. It may be associated with antibodies that attack certain proteins in the nucleus in cells and affected tissues.