Key Area 4.2: Specific Cellular Defences

Question 1

What are body tissues monitored by?

Answer 1

A range of white blood cells that constantly circulate and provide immune survaliance.

Question 2

What happens if tissues are damaged or invaded?

Answer 2

Certain cells release cytokines, which increase blood flow to the site of damage and invasion.

Question 3

What does increase blood flow at the site of infection or damage lead to?

Answer 3

Accumulation of specific white blood cells.

Question 4

What does each lymphocyte have?

Answer 4

A single type of meme brand receptor specific to one type of antigen.

Question 5

What does a lymphocyte do?

Answer 5

Responds to antigens on pathogen cells, infected cells or toxins released by pathogens.

Question 6

What happens when a lymphocyte binds to an antigen?

Answer 6

Repeated lymphocyte division which produces a clone of identical lymphocyte cells.

Question 7

What are the two broad categories of lymphocyte?

Answer 7

T lymphocytes and B lymphocytes.

Question 8

What is clonal selection theory?

Answer 8

The selection of lymphocytes by antigens and their response in producing a clone.

Question 9

What do T lymphocytes have?

Answer 9

Specific surface proteins that allow them to disturb guide between the surface molecules of the body’s own cells and cells with foreign molecules on their surfaces

Question 10

What do T lymphocytes do in autoimmunity?

Answer 10

Respond to the body’s own cell surface antigens and produce auto immune disease.

Question 11

What can T lymphocytes do?

Answer 11

• One group can release cytokines which activate B lymphocytes and phagocytes. Phagocytes that engulf pathogens display fragments of the pathogens antigens on their surfaces.
• One group destroy infected cells by inducing apoptosis.

Question 12

What do antigen resenting cells active?

Answer 12

T lymphocytes which move to the site of infection guided by the presence of cytokines in the area.

Question 13

What do B lymphocytes clone do?

Answer 13

Produce specific antibody molecules which recognise specific antigens on the surface of a pathogen or a toxin.

Question 14

What do B lymphocytes activated by antigen presenting cells and stimulated by T lymphocytes produce?

Answer 14

A clone of B lymphocytes which secrete antibodies into the blood and lymph to transport them to infection sites.

Question 15

What role do B lymphocytes play in allergies.

Answer 15

Response to an antigen that is normally harmless.

Question 16

What do some T and B lymphocytes produced by clonal selection survive as?

Answer 16

Memory cells.

Question 17

What does a secondary exposure to the same antigen give rise to?

Answer 17

A clone of the new lymphocytes producing a more rapid and greater immunological response than to the primary exposure.