unit 5 Flashcards

1
Q

what is immunity

A

protection from infectious diseases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

how does the immune system achieve this

A

limiting invasion of foreign agents and destroys damaged and infected cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what mechanism is the immune system

A

it is a defence mechanism against harmful invading micro - organisms such as bacteria, vrisuses and fungi.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is innate immunity

A
  • non specific defence
  • passive, a physical anf chemical barrier to the entry of pathogens
  • active, humoral - complements , blood proteins
    -cellular, NK cells & phagocytes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is adaptive immunity

A
  • specific defences
  • humoral, antibodies
  • celuloar , T cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Characteristics of innate immunity

A
  • Inborn
  • older in evolutionary development
  • non specific for diff pathogens
  • rapidly deployed
  • non - adaptive, do not increase with repeated exposure
  • provide initial defnce to stop infection and contain it until adaptove immunity develops
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Main immune cells of innate immunity

A
  • macrophages
  • neutrophils
  • eosinophils
  • NK cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Characteristics of adaptive immunity

A
  • accquired after exposure
  • relatively later addition in verterbrates
  • highly specific for the pathogen responsible fpr the initial infection
  • requires 3/7 days to activate
  • highly adaptive, increases with each occuring exposure
  • devloped if innate sytem is penetrated and needed for ultimate clearance of the infective agent.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

main immune cells of adaptive immunity

A
  • B lympocytes
  • T lymphocytes
  • macrophages
  • antigen presenting cells APCs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are cytokines

A
  • the chemical mediators (hormones) of the immune sytem.
  • are small soluble proteins produced by cells of the innate and adaptive immunity, 100s of cytokines and more being discovered
  • immune system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is the role of cytokines in the immune response

A
  • immune response requires actions of cells and many immunocytes of other systems.
  • communications bewteen cells involve both specialized physical contacts between them snd release chemical mediators such as cytokines.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

antibodies

A

produced by activated B-lymphocytes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Structure of antibodies

A
  • has a Y shaped structure with two identical heavy chains and two identical light chains.
  • each chain contains both constant segment and variable segment.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

function of antibodies.

A
  • an antibody molecule has two antigen binding sites which form from the segments of the chains which bind to antigenic determinant sites/ etiopes of antigen molecules.
  • differences in the structure of the variable segments affect the shape and binding site.
  • the differences make the antibodies specific for different antigens.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

facts

A

Each b cell is commited to produce antibody of one specificity.
The class that the antibody will produce depends on the way the B cell is activated by the antigen in the lymphoid tissue which is determined by the nature of the antigen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Consequences of antigen - antibody interactions

A
  • neutralization and agglutination
  • opsonisaation, increasing phagocyte effeciency
  • complement fixation
  • prevention of bacterial viral adhesion
  • stimulation of inflammation
17
Q

what is neutralization and agglutination ?

A
  • is caused by the change in the physical property due to the formation of the complex.
18
Q

what are T cells

A

T cells are responsible for cell - mediated adaptive immunity

19
Q

types of T cells

A
  • when antigen triggers the adaptive immune response T cells are activated first before B cells.
  • T cells (CD8 T cells) directly attacl infected& altered cells such as tumour cells.
  • CD4 T cells/ helper cells are often the only and first activated T cells responding to intracellular bacteria in immune reponses.
  • Helper T cells stimulate B cells so correct antibdoies are made and help CD8 t cells to beecome activated.
20
Q

what are CD4 and CD8

A
  • they are self surface molecules which are present on the cells which help them to characterise them.
  • CD4 T helper cells are the first immunocytes to get activated by the antigen.
  • they cannot percieve the antigenm on their own and has to be presented by anotehr cell in the correct way.
21
Q

what are APC’s

A
  • the cells that present antigem to the T cells so they become activated are known as Antigen - Presenting cells
22
Q

Types pf APC’s

A
  • dendritic cells
  • activated macrophages
  • B cells

the cells internalise the antigen, breakes them into smaller fragments.

23
Q

Antigen recognition by T cells

A
  • for T cells to be activated the processed antigens need to be presented by antigen presenting cells such as peptide antigens.
  • CD4 T helper cells recognise antigens of extracellular origin wheras antigens of cytoplasmic origin are recognised by CD8 T cells.
24
Q

what is the second signal

A

Co - stimulation which acts as a confirmation of initial signal for T cells to become activated.

25
Q

what does

A