Immunology and Neurobiology Unit 3 KA 6

Question 1

What are Lymphocytes?

Answer 1

Lymphocytes are white blood cells that carry out a specific immune response

Question 2

What are Lymphocytes made out of?

Answer 2

Lymphocytes are made out of stem cells in bone marrow

Question 3

What do Lymphocytes respond to?

Answer 3

Lymphocytes respond to specific antigens on invading pathogens

Question 4

What are Antigens?

Answer 4

Antigens are molecules (often proteins) located on the surface of cells that trigger an immune response

Question 5

What are the two types of Lymphocytes?

Answer 5

1) T Lymphocytes
2) B Lymphocytes

Question 6

What does Antigen binding lead to?

Answer 6

Antigen binding leads to repeated lymphocyte division resulting in the formation of a clonal population of identical lymphocytes

Question 7

What do B Lymphocytes do?

Answer 7

B Lymphocytes produce antibodies against antigens, leading to the destruction of the pathogen

Question 8

What are Antibodies?

Answer 8

Antibodies are Y-shaped proteins that have receptor binding sites specific to a particular antigen on a pathogen

Question 9

What happens when Antibodies become bound to the antigens?

Answer 9

When Antibodies bind to antigens, they inactivate the pathogen

Question 10

How is the antigen-antibody complex destroyed?

Answer 10

The antigen-antibody is destroyed by Phagocytosis

Question 11

What happens when B Lymphocytes respond to antigens on substances which are harmless to the body?

Answer 11

When B Lymphocytes have a hypersensitive response and respond to antigens on substances which are harmless to the body it causes an Allergic reaction

Question 12

What do T Lymphocytes do?

Answer 12

T Lymphocytes destroy the infected body cells by recognising antigens of the pathogen on the cell membrane and inducing Apoptosis

Question 13

What is Apoptosis?

Answer 13

Apoptosis is programmed cell death

Question 14

What happens to T Lymphocytes when they attach on to the infected cells?

Answer 14

When T Lymphocytes attach on to the infected cells, they release proteins which diffuse into the infected cells causing production of self-destructive enzymes which cause Apoptosis (cell death)

Question 15

How are the remains of cells removed after they have undergone Apoptosis?

Answer 15

After a cell has undergone Apoptosis, the remains are removed by Phagocytosis

Question 16

What happens when T Lymphocytes fail to distinguish between the body cells self-antigens and non-self antigens on infected cells?

Answer 16

When T Lymphocytes fail to distinguish between the body cells self-antigens and the non-self antigens on infected cells it leads to Autoimmune diseases as the T Lymphocytes respond to self-antigens

Question 17

What happens to some of the cloned T and B Lymphocytes that are produced in response to antigens?

Answer 17

Some cloned T and B Lymphocytes that are produced in response to antigens will survive long term as Memory cells

Question 18

What do Memory cells do after a second exposure to an antigen?

Answer 18

After a second exposure to an antigen occurs, Memory cells will rapidly give rise to a new clone of specific lymphocytes which destroy the invading pathogen before the individual shows symptoms

Question 19

Primary vs Secondary Immune response:
1) What is the immune response?
2) What is the antibody concentration?
3) Is the response sufficient?

Answer 19

Primary response -
1) No measurable response for the first few days, then antibody production grows steadily
2) Lower antibody concentration
3) Response is not sufficient in stopping the invading pathogen, individual will display symptoms

Secondary response-
1) Rapidly increasing antibody production
2) Higher antibody concentration
3) Response is sufficient in destroying invading pathogen before the individual shows symptoms

Question 20

What does the human immunodeficiency virus (HIV) do?

Answer 20

HIV attacks and destroys T Lymphocytes which leads to the development of AIDS

Question 21

What happens to people with AIDS?

Answer 21

People with AIDS have a weakened immune system and are left more susceptible to infections