Immune Response Flashcards
1
Q
What is immunity ?
A
- is the ability of organisms to resist diseases due to defence mechanisms that destroy pathogens before they can cause harm.
2
Q
Features of no specific response
A
- immediate response = happens all the time
- same process of all pathogens
- 1st line defence mechanism
E.g. physical barrier - skin, eyelashes, tears, sweat
Phagocytosis
3
Q
Features of specific response
A
- slower but specific to each pathogen
- 3rd line defence
E.g. cell mediated response - T cells
Humoral response - B cells
4
Q
How does cells recognise other cells ?
A
- each specific protein in each cell gives recognition - it has large variety and highly specific 3D tertiary structure
- allow immune system to identify pathogens, non self cells, toxins and abnormal body cells
5
Q
What is the 2nd line of defence include ?
A
- phagocytosis
- inflammation + fever
- anti microbial substance
6
Q
What is lymphocytes ?
A
- are whittle blood cells involved in specific immune response
7
Q
Features of T lymphocytes
A
- made in bone marrow, mature in thymus gland
- for cell mediated response
- respond to non self materials inside body cells - virus and own cells altered by cancer / transplanted
8
Q
Process of phagocytosis
A
- pathogens release cytokines as an attractant to cause phagocytes to move towards itself
- phagocytes have receptors on CSM that recognise and attach to chemicals on the surface of pathogens
- phagocytes engulf pathogens - form phagosome around
- lysosome of phagocytes move into and fuse phagosome= phagolysosome
- lysozymes hydrolyse p’s cell wall to destroy it
- soluble products from hydrolysis will be absorbed in cytoplasm of phagocytes
9
Q
How does phagocytes become an APC after phagocytosis ?
A
- it display non self antigens on its surface membrane = become APC to alert immune system cells to the presence of non self antigen
10
Q
What is antigens ?
A
- part of organisms that is recognised as non self by immune system and which triggers immune response
- proteins that are part of CSM of non self cells
- can triggers production of antibodies
11
Q
Features of B lymphocyte
A
- respond to humoral immunity
- made and mature in bone marrow
- involving antibodies that present in body fluids e.g. blood
12
Q
What does APC do ?
A
- triggers cell mediated response by T cells by displaying non self antigens on their CSM
13
Q
4 Examples of cells that display NS antigens
A
- infected body cells with viral antigens on CSM
- a phagocyte with destroyed pathogens
- transplanted cells - form different shapes antigens than own cell antigens
- cancer cells have abnormal shaped self antigens
14
Q
Process of cell mediated response
A
- Once pathogen’s antigens present on phagocytes = APC
- helper T cells have complementary receptors that attach to antigens of APC
- it activates Th and starts cloning by mitosis to make large amount of clones
- cloned Th differentiate into other types of cells
15
Q
4 cells that Th differentiate into :
A
- remains Th cells + activate B lymphocytes
- stimulate phagocyte into phagocytosis
- become memory cells for specific shaped antigens
- become cytotoxic T cells
