Physiology of Joints - 04/10/18 Flashcards Preview

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Flashcards in Physiology of Joints - 04/10/18 Deck (67)
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1
Q

What are the three types of joints?

A

Synovial
Fibrous
Cartilaginous

2
Q

What is another name for fibrous joints?

A

Synarthrosis

3
Q

What are fibrous joints?

A

Bones united by fibrous tissue

4
Q

Do fibrous joints allow movement?

A

No`

5
Q

What is an example of a fibrous joint?

A

Skull sutures

6
Q

What is another name for cartilaginous joints?

A

Amphiarthrosis

7
Q

Do cartilaginous joints allow movement?

A

Yes but limited

8
Q

What are some examples of cartilaginous joints?

A

Intervertebral discs
Pubic symphisis
Part of sacroiliac joints
Costochondral joints

9
Q

What is another name for synovial joints?

A

Diarthrosis

10
Q

What are synovial joints?

A

Bones separated by a cavity and united by a fibrous capsule

11
Q

What is in a synovial joint?

A

Synovial fluid

12
Q

What is the inner aspect of the fibrous capsule lined with in synovial joints?

A

Synovial membrane

13
Q

What is the synovial membrane made of?

A

Vascular connective tissue

14
Q

What type of cell are present in the synovial membrane?

A

Synovial cells aka Fibroblasts

15
Q

What produces the synovial fluid?

A

Synovial cells

16
Q

What covers the articular surfaces of bone?

A

Cartilage

17
Q

What are the two types of synovial joints?

A

Simple

Compound

18
Q

What is a simple synovial joint and what is an example?

A

One pair of articular surfaces

19
Q

What is a compound synovial joint and what is an example?

A

More than one pair of articular surfaces

20
Q

How are joints supported?

A

Extra-articular surfaces

21
Q

What are 3 extra articular surfaces?

A

Bursa
Tendon
Ligament

22
Q

What are the two physiological functions of joints?

A

Structural support

Purposeful motion

23
Q

What are the 3 roles of joints during purposeful motion?

A
Stress distribution
Confer stability
-Shape of the articular component
-Ligaments
-Synovial fluid 
Joint lubrication
24
Q

What provides joint lubrication?

A

Cartilage interstitial fluid
Synovium derived hyaluronic acid (mucin)
Synovium derived lubrcin

25
Q

What are the 5 functions of synovial fluid?

A
Lubricates Joint
Facilitates joint movements
Helps minimize wear and tear
Aids in nutrition of articular cartilage
Supplies the chondrocytes (cartilage cells) with O2 and nutrients and removes CO2 and waste products
26
Q

Is the synovial fluid a static poole?

A

No

It is constantly replenished and absorbed

27
Q

Is synovial fluid viscous and why?

A

Yes

Mainly due to the presence of hyaluronic acid (mucin) produced by synovial cells

28
Q

What are some other components of synovial fluid and how are they derived?

A

Uric acid

By dialysis of blood vessels

29
Q

Are there lots of cells in the synovial fluid?

A

Usually very little

30
Q

What does rapid movement do to the synovial fluid?

A

Decreases viscosity

Increases elasticity

31
Q

What is an example of a condition where the synovial fluid becomes defective?

A

Osteoarthritis

32
Q

What does normal synovial fluid look like/

A

Clear and colourless

33
Q

How many WBCs are in synovial fluid?

A

<200WBC/mm3

34
Q

When does the WBC count increase in the synovial fluid?

A

Inflammatory and septic arthritis

35
Q

When does the synovial fluid turn red?

A

Traumatic synovial tap

Haemorrhagic arthritis

36
Q

What colour is inflammatory synovial fluid?

A

Yellow

37
Q

What are the two functions of articular cartilage?

A

Prevents wear and tear

Distributes contact pressure to subchondral bone

38
Q

What determines the mechanical properties of cartilage?

A

The composition of the cartilage ECM and the interaction between the fluid and solid phase of cartilage

39
Q

From superior to inferior, name the structure of articular cartilage?

A
Articular surface
Superficial zone
Middle zone
Deep zone
Calcified zone
Subchondral bone
40
Q

How are the zones of articular cartilage differ?

A

Organization of collagen fibres and relative content of cartilage components

41
Q

What type of cartilage is articular cartilage?

A

Hyaline

42
Q

What are the properties of articular cartilage?

A

Elastic

Sponge-like

43
Q

Where does articular cartilage cover?

A

Articular surfaces of bones

44
Q

What is the ECM made up of?

A

70% Water
20% Type 2 collagen
10% Proteoglycans

45
Q

What accounts for 70% of the cartilage wet weight?

A

Water

46
Q

Where is 80% of cartilage water distributed?

A

Near the articular surface

47
Q

What happens to cartilage water content with age?

A

It decreases

48
Q

What does the water in cartilage allow?

A

Maintains resiliency of the tissue and contributes to the nutrition and lubrication system

49
Q

What accounts for 20% of the cartilage wet weight?

A

Collagen

50
Q

What type of collagen is present in cartilage?

A

Type 2

51
Q

What in the function of the collagen in the cartilage?

A

Maintains cartilage architecture

Provides tensile stiffness and strength

52
Q

What accounts for 10% of cartilage wet weight?

A

Proteoglycan

53
Q

Where is the highest concentration of proteoglycan found?

A

Middle and deep zone

54
Q

What is proteoglycan composed of?

A

Mainly glycosaminoglycan

55
Q

What is proteoglycan responsible for?

A

Compressive properties associated with load bearing

56
Q

What makes up >98% of cartilage volume?

A

ECM

57
Q

What synthesizes, organizes, degrades and maintains the ECM?

A

Chondrocytes

58
Q

Is the articular cartilage vascular or avascular?

A

Avascular

59
Q

What happens when there are changes in the amounts of each cartilage component?

A

It would change the mechanical properties of cartilage

60
Q

What would happen if the rate of ECM degradation happened faster than the rate of its synthesis?

A

Joint disease

61
Q

What are the catabolic factors of cartilage matrix turnover?

A

Stimulate proteolytic enzymes and inhibits proteoglycan synthesis
E.g. TNFa, IL-1

62
Q

What are the anabolic factors of the cartilage matrix turnover?

A

Stimulates proteoglycan syntheis and counteracts the effects of IL-1
E.g. TGF, IGF-1

63
Q

What are 2 markers of cartilage degradation?

A

Serum and synovial keratin sulphate
-increased levels indicate cartilage breakdown
-Level increases with age and patients with osteoarthritis
Type II collagen in synovial fluid
-Increased levels indicate cartilage breakdown
-Useful in evaluating cartilage erosion

64
Q

What can cause Rheumatoid arthritis?

A

Synovial cell proliferation

Inflammation

65
Q

What causes gouty arthritis?

A

Deposition of uric acid crystals

66
Q

What causes soft tissue rheumatism?

A

Injury and inflammation to periarticular structures

67
Q

What are 6 effects on the subchondral bone following cartilage wear and tear?

A
Thickened capsule
Cyst formation
Sclerosis in subchondral bone
Fibrillated cartilage
Synovial hypertrophy
Osteophyte formation

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