4.1.5 secondary non-specific defences Flashcards

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

antigen-presenting cell

A

cell that isolates the antigen from a pathogen & places it on the plasma membrane so it can be recognised by other cells in the immune system

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

clonal selection

A

selection of a specific B or T cell thats specific to the antigen

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

cytokines

A

hormone-like molecules used in cell signalling to stimulate the immune response

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

neutrophil

A

type of white blood cell that engulfs foreign matter & traps it in a large vacuole (phagosome) which fuses with lysosomes to digest the foreign matter

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

opsonins

A

proteins that bind me to the antigen on a pathogen & allow phagocytes to bind

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

what are secondary defences used for

A

combat pathogen that have entered the body

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

what are antigens

A

chemical markers on the outer membrane of an invading pathogen

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

describe antigens

A
  • proteins or glycoproteins intrinsic to the plasma membrane
  • specific to organism
  • own cells have antigen but are recognised as our own & don’t produce a response
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are opsonins a type of

A

antibody

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

are opsonins specific

A

some aren’t so can attach to a variety of pathogenic cells

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

role of opsonins

A

enhance ability of phagocytic cells to bind & engulf the pathogen

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

what’s the first line of secondary defence

A

phagocytosis

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

what’s the most common phagocytes

A

neutrophils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what’s the nucleus of neutrophils like

A

multi-lobed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

where are neutrophils manufactured

A

bone marrow

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

describe neutrophils

A
  • travel in blood & often squeeze out via tissue fluid
  • short-lived
  • released in large numbers as result of infection
  • contain large number of lysosomes
  • engulf & digest pathogens
  • die soon after ingesting few pathogens
  • dead neutophils may collect in area of infection forming pus
17
Q

outline the process by which neutrophils engulf & digest pathogens

A
  1. neutrophil binds to opsonin attatched to antigen of pathogen
  2. pathogen’s engulfed by endocytosis forming a phagosome
  3. lysosomes fuse to phagosome & release lytic enzymes into it
  4. (after digestion) harmless products are absorbed into cell
18
Q

what are macrophages

A
  • larger cells manufactured in bone marrow
  • travel in blood as monocytes before settling in body tissues
19
Q

where are many monocytes found & what do they become

A

found in lymph nodes & mature into macrophages

20
Q

type of macrophage found in more peripheral tissues

A

dendritic cells

21
Q

important role of macrophages

A

initiate specific responses to invading pathogen

22
Q

what do macrophages do when they engulf a pathogen

A

does not fully digest it
- antigen from surface is saved & moved to special protein complex on surface of the cell
- the cell becomes an antigen-presenting cell (exposes the antigen on its surface so other cells in the immune system can recognise it)

23
Q

what does the special-protein complex ensure

A

that the antigen-presenting cell isn’t mistaken for a foreign cell & attacked by other phagocytes

24
Q

where does the antigen-presenting cell move & why

A

moves around the body where it can come into contact with specific cells that can activate the full immune response
- these are T & B lymphocytes
(may be only 1 of each with the correct recognition site for the antigen so these antigen-presenting cells increase the chances the antigen will come into contact with them)