Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

LOCO2 > Pathogenesis Of Rheumatoid Arthritis > Flashcards

Pathogenesis Of Rheumatoid Arthritis Flashcards

1
Q

2 types of synoviocytes

A

Type a bone marrow derived macrophage
Type b fibroblast like connective tissue cell

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

Characteristics of synovial membrane basement membrane

A

No basement membrane

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

What is contained in the sub intima of the synovial membrane

A

Dense network of Fenestrated capillaries
Fat
Loose areola CT

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

What is synovial fluid

A

Ultrafiltrate of blood with added hylauronic acid which forms a thin film over articulate surfaces

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

Histological structure of synovial membrane

A

Synoviocytes sitting directly on highly vascular subintima

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

How is synovial fluid produced

A

Leaky Fenestrated capillaries allow plasma out

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

Characteristics of synovial membrane that allows plasma/synovial fluid to easily flow in and out between blood membrane and joint cavity

A

Fenestrated capillaries
Loose areola or CT
No basement membrane between subintima and synoviocytes

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

Normal colour of synovial fluid

A

Colourless to clear pale yellow
Can read text through

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

What causes red or brown synovial fluid

A

Haemorrhage into joint

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

What causes yellow cloudy synovial fluid

A

Inflammation

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

What causes white or cream and cloudy or shimmery synovial fluid

A

Crystals

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

What causes yellow, purulent, or lumpy synovial fluid

A

Bacterial infection

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

Synovial fluid pH

A

7.38

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

How many g/L of hylauronate is in synovial fluid

A

3g/L

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

Why is synovial fluid thicker at rest and thins on movement

A

Protects cartilage at start of movement
Hylauronic acid and proteins inc lubricin interact more at rest and detangle on movement

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

How far apart are articulating surfaces kept by synovial fluid

A

50um

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is synovial fluid seeping into articulate cartilage called

A

Weeping lubrication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Purpose of weeping lubrication

A

Reduce friction
Reserve volume
Nourish articulate cartilage

19
Q

string length of normal synovial fluid and synovial fluid in RA

A

4-6cm normal
RA <1cm

20
Q

Why is synovial fluid less viscoelastic in RA than normal

A

Less hylauronic acid

21
Q

Mucin clot test

A

2-5% acetic acid added to synovial fluid, clot surrounded by clear fluid forms in health, no clot in RA

22
Q

Mucin clot test result in RA

A

no clot or clot that breaks up easily
Due to less hylauronic acid

23
Q

Features of RA

A

Synoviocyte proliferation
Infiltration of inflammatory cells
Subintima fibroblast proliferation

24
Q

Do type a or type b synoviocytes proliferate more in RA

A

Type a

25
Q

Which types of inflammatory cells infiltrate the synovial fluid and subintima in RA

A

Syn fluid - neutrophils
Subintima - lymphocytes

26
Q

Why is the subintima of the synovial membrane thickened in RA

A

Fibroblast proliferation

27
Q

Why are synovial joints susceptible to inflammatory injury

A

Fenestrated capillaries so immune cells can easily enter
Limited responses

28
Q

Pannus

A

Inflamed synovial membrane

29
Q

How does pannus cause joint and bone erosion

A

Secretes cytokines, autoantibodies, and signalling mols that increase Clast activity

30
Q

What forms lymphoid nodules in pannus and where do they form

A

Collections of Th17 subset of CD4 T lymphocytes
Form around small blood vessels

31
Q

What tissue does pannus invade

A

Bone

32
Q

What molecules lead to bone erosion in RA

A

Anti citrullinated protein antibodies
IL8
RANKL
Cytokines from Synovitis
DKK1
Sclerostin

33
Q

How does anti citrullinated protein antibodies cause bone erosion

A

Stimulates osteoclast differentiation

34
Q

Role of IL8 in RA

A

Produced by osteoclasts
Induces more osteoclasts by Autocrine feedback
Sensitises nociceptors increasing pain
Attracts neutrophils and induces NETosis

35
Q

How do cytokines from Synovitis cause bone erosion

A

Stimulate osteoclast prolif and differentiation
Induce RANKL expression

36
Q

Rheumatoid factor

A

IgM autoantibody that attacks IgG increasing inflammation

37
Q

Role of IL-17 in RA

A

secreted by Th17 cells infiltrating joint
Induce RANKL on synovial fibroblasts
Stim local inflam
Activate synovial macrophages to secrete pro inflammatory cytokines

38
Q

How do pro inflammatory cytokines released from pannus switch off the repair mechanism of bone in RA

A

Induce DKK1 expression by synovial fibroblasts -> inhibit osteoblasts and induces sclerostin expression by osteocytes -> sclerostin inhibits osteoblasts

39
Q

Which cells are most numerous in inflammatory synovial effusion

A

Neutrophils

40
Q

How do neutrophils increase free radical damage in RA

A

Cause respiratory burst producing superoxide anion radical

41
Q

How does RA effect synovial fluid volume

A

Increase
Cytokines make vessels more leaky

42
Q

Roles of activated synovial fibroblasts, b cells, T cells, macrophages, and neutrophils in RA

A

ACFs - stim osteoclasts and MMP production to degrade cartilage and bone matrix
B cells - mature to plasma cells and produce autoantibodies
T cells - pro inflammatory cytokines
Macrophages - pro inflammatory ctokines and differentiate to osteoclasts
Neutrophils - NETosis, free radical damage

43
Q

What causes damage to hylauronic acid in RA

A

Free radical damage by oxygen

LOCO2 (26 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions