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Flashcards in Specific cellular defences against pathogens Deck (25)
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1

What are lymphocytes?

White blood cells

2

What are lymphocytes involved in?

The specific immune response

3

What does the lymphocytes single type of membrane receptor do?

It's specific for one antigen

4

What does antigen binding lead to?

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

5

What are antigens?

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

6

Where are antigens located?

on the surface of cells that trigger a specific response

7

What are the two types of lymphocytes?

B lymphocytes and T lymphocytes

8

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

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

9

Describe the structure of antibodies

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

10

How can antigen-antibody complex be destroyed?

By pathocytosis

11

What can B lymphocytes respond to?

Antigens on substances that are harmless to the body eg pollen

12

What is a hypersensitive response called?

An allergic reaction

13

What do T lymphocyte destroy?

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

14

What is apoptosis?

Is programmed cell death

15

What does T lymphocytes attach onto?

Infected cells

16

What do T lymphocytes release

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

17

What can T lymphocytes normally distinguish between?

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

18

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

T lymphocytes responding to self antigens. This causes autoimmune disease

19

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

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

20

What do cloned B and T lymphocytes survive as?

long term memory cells

21

What happens when exposure to the same antigen occurs?

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

22

What happens during secondary response?

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

23

What does HIV attack and destroy?

T lymphocytes.

24

What does HIV cause?

depletion of T lymphocytes which leads to the development of AIDS

25

What do individuals with AIDS have?

Weakened immune system and so are more vulnerable to opportunistic infections