Specific cellular defences against pathogens

Question 1

What are lymphocytes?

Answer 1

White blood cells

Question 2

What are lymphocytes involved in?

Answer 2

The specific immune response

Question 3

What does the lymphocytes single type of membrane receptor do?

Answer 3

It’s specific for one antigen

Question 4

What does antigen binding lead to?

Answer 4

Repeated lymphocytes division resulting in the formation of a clonal population of identical lymphocytes

Question 5

What are antigens?

Answer 5

Molecules, often proteins located on the surface of cells that trigger a specific response

Question 6

Where are antigens located?

Answer 6

on the surface of cells that trigger a specific response

Question 7

What are the two types of lymphocytes?

Answer 7

B lymphocytes and T lymphocytes

Question 8

What do B lymphocytes produce and what does it lead to ?

Answer 8

Antibodies against antigens and this leads to the destruction of the pathogen

Question 9

Describe the structure of antibodies

Answer 9

Y shaped proteins
Have receptors binding sites specific to particular antigen on a pathogen
Antibodies become bound to antigens inactivating the pathogen

Question 10

How can antigen-antibody complex be destroyed?

Answer 10

By pathocytosis

Question 11

What can B lymphocytes respond to?

Answer 11

Antigens on substances that are harmless to the body eg pollen

Question 12

What is a hypersensitive response called?

Answer 12

An allergic reaction

Question 13

What do T lymphocyte destroy?

Answer 13

Infected body cells by recognising antigens of the pathogen on the cell membrane and inducing apoptosis

Question 14

What is apoptosis?

Answer 14

Is programmed cell death

Question 15

What does T lymphocytes attach onto?

Answer 15

Infected cells

Question 16

What do T lymphocytes release

Answer 16

Proteins. These proteins diffuse into the infected cells causing production of self destructive enzymes which cause cell death. The remains of the cell are then removed by phagocytosis

Question 17

What can T lymphocytes normally distinguish between?

Answer 17

Self antigens on the boy’s own cells and no specific antigens on infected cells

Question 18

What does failure of the regulation of the immune system lead to?

Answer 18

T lymphocytes responding to self antigens. This causes autoimmune disease

Question 19

In autoimmunity what do the T lymphocytes attack and the effect?

Answer 19

Body’s own cells .Causes autoimmune diseases such as Type 1 diabetes and rheumatoid arthritis

Question 20

What do cloned B and T lymphocytes survive as?

Answer 20

long term memory cells

Question 21

What happens when exposure to the same antigen occurs?

Answer 21

Memory cells rapidly give rise to a new clone of specific lymphocytes. They destroy the invading pathogens before the individual shows symptoms

Question 22

What happens during secondary response?

Answer 22

antibody production is greater and more rapid than during the primary response

Question 23

What does HIV attack and destroy?

Answer 23

T lymphocytes.

Question 24

What does HIV cause?

Answer 24

depletion of T lymphocytes which leads to the development of AIDS

Question 25

What do individuals with AIDS have?

Answer 25

Weakened immune system and so are more vulnerable to opportunistic infections