Lymphocytes

Question 1

What is an antigen?

Answer 1

a molecule that triggers an immune response

Question 2

Define specific response

Answer 2

slower response but can provide long term immunity

Question 3

What response do Lymphocytes give?

Answer 3

Specific

Question 4

Define Lymphocyte?

Answer 4

white blood cell produced by stem cells in the bone marrow.

Question 5

What are the two types of lymphocytes and how do they differ?

Answer 5

B-cells=mature in bone marrow, provide humoral immunity and involve antibodies in fluids

T-cells=mature in the thymus gland, provided cell-mediated immunity and involves body cells

Question 6

What immunity is associated with T-cells?

Answer 6

cell-mediated immunity

Question 7

What can T-cells distinguish between?

Answer 7

self and nonself antigens hence normal and abnormal/invader cells

Question 8

Name 4 types of abnormal cells

Answer 8

presenting pathogen antigens on phagocytes cell surface membrane
body cells invaded by virus
transplant cells
cancer cells

Question 9

What are cells that display foreign antigens on their surface called?

Answer 9

antigen-presenting cells

Question 10

Describe the stage of the cell-meditated immunity/ cellular response?

Answer 10

pathogen invades body cell/is taken in via phagocytosis

phagocyte presents pathogen antigen on its cell surface membrane

T-helper cells specific receptor fit onto these antigens

attachment activates T-cells to divide by mitosis to form genetically identical clones

Question 11

What is the cellular response?

Answer 11

same as cell-mediated immunity

Question 12

What can helper T-cells activate/divide by mitosis into?

Answer 12

activate Cytotoxic/Killer T-cells
develop into memory cells for a rapid response to future invasions
stimulate B-cells to release antibodies
stimulate phagocytosis

Question 13

Define cytotoxic T-cells?

Answer 13

produces a protein called perforin that makes holes in the cell-surface membrane which causes it to be freely permeable and die.

Question 14

Appprixiametly how many B-lymphocytes are you born with?

Answer 14

10 million different types

Question 15

Define Humoral Immunity

Answer 15

involves antibodies ( which are soluble in the blood and tissue fluid)

Question 16

How are a variety of B-cells involved in a response to one pathogen?

Answer 16

Each pathogen has a variety of different antigens on its surface. An antigen is complementary to a protein receptor on a B-lymphocyte so many B-cells are involved to bind to all the different antigens.

Question 17

What is clonal selection?

Answer 17

When an antigen enters a B-cell via endocytosis and gets presented on the surface,

Helper T-cells bind to the processed antigens and stimulate B-cells to divide via mitosis

to form clones which all produce specific antibody to the foreign antigen.

Question 18

What are monoclonal antibodies?

Answer 18

One clone produces one antibody

Question 19

What can cloned B-cells develop into?

Answer 19

Plasma cells and memory cells

Question 20

What are plasma cells?

Answer 20

secrete antibodies into the blood plasma,
can survive for a few days
part of the primary immune response

Question 21

What are memory cells?

Answer 21

Part of the secondary immune response
doesn’t directly produce antibodies
results in a faster response next time the antigen is present and gives long term immunity

Question 22

What do pathogens do in the body?

Answer 22

Release toxins

damage to cells

Question 23

Describe the stage of the humoral response

Answer 23

Surface antigens of pathogens take up by a B-cell
B-cell processes antigen and presents it on its cell surface
Helper T-cells attached to processed antigens and activate B-cells
B-cell is activated to divide by mitosis to give clones

Cloned plasma cells produce and secrete specific antibodies that are complementary to surface antigens on the pathogen

Antibodies destroys the pathogen

Memory cell can divide into plasma cells for future response