Specific Immune Response

Question 1

Where do mature lymphocytes circulate in?

Answer 1

The spleen, lymph nodes, adenoids and tonsils
Lymphatic system and general circulation of the blood

Question 2

How can lymphocytes be activated?

Answer 2

By one particular antigen (specific immune response)

Question 3

What are B lymphocytes?

Answer 3

Lymphocytes which mature in the bone marrow and then migrate to the lymph nodes

Question 4

What are T lymphocytes?

Answer 4

lymphocytes which migrate to the thymus gland for a period of maturation before migrating to the lymph nodes

Question 5

What do mature B cells (plasma cells) produce?

Answer 5

Antibodies- destroy pathogens or neutralise toxins

Question 6

Are lymphocytes made in response to a foreign cell?

Answer 6

no- they already exist

Question 7

What type of cell does humoral immunity involve?

Answer 7

B cells

Question 8

What does humoral immunity involve?

Answer 8

Antibodies and antibodies are soluble in blood and tissue fluid (humour)

Question 9

Cell-mediated immunity (T cells)?

Answer 9

T lymphocytes only respond to antigens presented on CSM e.g. an antigen presenting cell (rather than antigens in tissue fluid)

Question 10

What type of antigens are the specific immune response activated by?

Answer 10

Non-self antigens i.e. from foreign organisms

Question 11

Antibodies?

Answer 11

Very specific binding site
3D protein shape
Found on cells or in plasma of blood

Question 12

Cell mediated response?

Answer 12

T lymphocytes can distinguish these invader cells from normal cells because:
Phagocytes that have engulfed and hydrolysed a pathogen present some of the pathogens antigens on their own CSM
Body cells invaded by virus present some viral antigens their own CSM
Transplanted cells (from same species) have different antigens on CSM
Cancer cells are different from normal body cells and present antigens on their CSM

Question 13

Cell mediated immune response?

Answer 13

Pathogens invade body cells or are taken in by phagocytes
The phagocyte displays antigens from the pathogen on its CSM
Receptors on the cell fit exactly on these antigens
This attachment activates T cell to divide rapidly by mitosis and form a clone of genetically identical cells
These cloned T cells:
- develop into memory cells
- stimulate phagocytes to engulf pathogens
- stimulate B cells to divide and secrete antibodies
- activate T cells

Question 14

What do cytotoxic cells do to T cells?

Answer 14

Protein made make holes in the CSM
These holes mean that the CSM is freely permeable to all substances and the cell dies as a result