The Immune System Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

Phagocytosis

A

Phagocyte recognises foreign antigens on pathogen
Phagocyte cytoplasm surrounds and engulfs pathogen
Pathogen contained in phagocytic vacuole in phagocyte cytoplasm
Lysosome fuses with vacuole
Lysozymes break down pathogen
Phagocyte presents pathogen’s antigens on its surface
other immune system cells activated

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

Phagocyte

A
i.e. a macrophage
form of WBC
carries out phagocytosis
first to respond to pathogens
found in blood and tissues
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

T-Cells

A

Activated by Phagocytes
different form of WBC
its receptor proteins bind to complementary antigens presented by phagocytes
T cell is then activated

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

Helper T Cells

A

release chemical signals to activate and stimulate phagocytes and cytotoxic T cells
Activate B cells

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

Cytotoxic T cells

A

kill abnormal and foreign cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

B Cells

A

Activated by T cells
WBC
covered in antibodies
bind to antigens forming antigen-antibody complexes
Each B cell has unique antibody on membrane
Clonal selection: Substances released from T Cell and binding activates B Cell
Activated B cell divides into plasma cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Plasma Cells

A

Identical to B cells
secrete many antibodies complementary to the antigen (monoclonal antibodies/MABS)
form many antigen-antibody complexes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Antibodies

A

Two binding sites - can bind to two pathogens at the same time
TF pathogens become clumped together - AGGLUTINATION
Phagocytes bind to antibodies and phagocytose many pathogens at once
process leads to destruction of pathogens carrying antigen in body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Antibody Structure

A

PROTEINS
specificity relies on variable regions
variable regions form antigen binding sites
each type of antibody has unique variable region (why only one antibody per pathogen)
All antibodies have the same constant regions
disulfide bridges keep constant regions together
hinge protein gives antibody ‘Y’ shape
| = heavy chain
\/ = light chains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Cellular Response

A

T cells and other immune system cells that they interact with
i.e. phagocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Humoral response

A

B Cells, clonal selection and the production of monoclonal antibodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Primary immune response

A

When antigen enters body for the first time
Slow - not many B Cells that can make necessary antibody
Eventually enough antibody produced
Sufferer shows symptoms of disease
Exposure to antigen means T and B cells produce memory cells
Memory cells remain in body for a long time
Memory T cells remember specific antigen
Memory B cells remember specific antibodies
Person is now immune - system has ability to respond quickly to a second infection

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

Secondary Immune Response

A

familiar pathogen enters body
Response is quicker and stronger
Clonal selection occurs faster
Memory B cells activated and divide into plasma cells that produce correct antibody to antigen
Memory T cells activated and divide into correct type of T cells to kill the pathogen
Response kills pathogen before symptoms occur

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