Musculoskeletal 4 Flashcards

1
Q

What is a disaccharide?

A

Two sugars

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

What is a repeating disaccharide unit called?

A

A glycosaminoglycans

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

Examples of a glycosaminoglycan?

A

Chondroitin (CS) and keratin sulphate (KS)

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

What is a proteoglycan?

A

Many glycosaminoglycans attached to a protein core

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

Example of a proteoglycan?

A

Aggrecan

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

Why do GAGs stand out like bristles on s brush on a proteoglycan?

A

Because the negative charges repel each other

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

What do proteoglycan attach to?

A

A long hyaluronic acid chain

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

What is a hyaluronic acid chain?

A

A large proteoglycan complex

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

What can extremely large hyaluronic acid chain molecules attach to?

A

Collagen fibre

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

What is recently unloaded cartilage like?

A

Has just had a compressive force taken away

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

What is the first stage of the loading cycle of articular cartilage?

A

Negative charges on the repeating disaccharide units cataract positive ions into the cartilage from the joint space; which increases ion concentration in the matrix

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

What mobile fluids enter the articular cartilage during the loading phase?

A
Ca
k
Na
H2O
Nutrients 
O2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How many glycosaminoglycans are attached to a core protein?

A

125 CS

50 KS

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

What’s the second phase of the articular cartilage loading cycle?

A

The increase in ion concentration creates an osmotic pressure/gradient which draws water into the matrix; the cartilage begins to swell with the influx of water

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

What is the third step of the loading cycle of articular cartilage?

A

As the cartilage swells the collagen is placed under increasing tension. Eventually the swelling force= the tensional forces, and the cartilage stops swelling. This is known as the unloaded equilibrium

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

What is the fourth step of the articular cartilage loading cycle?

A

When a load is introduced the fluid phase (water and positive ions- ie Ca, K, Na etc) is squeezes out of the cartilage and back into joint space and synovial fluid

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

What’s the last phase of the loading cycle of articular cartilage?

A

The loss of the fluid phase reduces the volume of cartilage (creep). This pushed the negative charges closer together. Eventually the compressive load will be supported by the solid phase and the repulsion of the negative charges. The cartilage will stop shrinking = loaded equilibrium

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

What are all synovial joints surrounded and enclosed by?

A

A joint capsule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What does the joint capsule form?

A

A “sleeve” around the joint connecting the ends of the contributing bones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the role of the articular capsule?

A

To not tightly hold the bones together, as this would restrict movement at the joint

21
Q

Why does the capsule have to be suitably loose?

A

To permit the joint to function properly

22
Q

When does the articular capsule become tight?

A

At the extreme limits of the natural range of joint motion, thereby protecting the joint from damage caused by excessive movement

23
Q

What is the articular capsule perforated by and reinforced by?

A

Perforated by vessels and nerves, reinforced by ligaments

24
Q

What are ligaments?

A

Dense regular connective tissue connecting bone to bone

25
Q

What is the articular capsule comprised of?

A

Outer fibrous layer and inner synovial membrane

26
Q

What is the fibrous layer of the articular capsule?

A

The outer layer of dense connective tissue with variable thickness

27
Q

What is the fibrous layer comprised of?

A

Parallel but interlacing bundles of white collagen fibres that are continuous with the periosteum of bone

28
Q

What are the thicker sections of the articular capsule sometimes called?

A

Capsular or intrinsic ligaments

29
Q

What do articular capsule ligaments in the fibrous layer, along with the rest of the capsule, resist?

A

Tensional forces, and are designed to check excessive and abnormal joint movement

30
Q

What does the fibrous layer support?

A

The synovial membrane

31
Q

What does the synovial layer protect?

A

The synovial membrane and the whole joint

32
Q

What is poorly vascularised but richly innervated?

A

The fibrous layer

33
Q

Why does it hurt to sprain your joints?

A

Because the fibrous capsule is poorly vascularised but richly innervated

34
Q

What is the synovial membrane?

A

An inner layer of loose connective tissue of variable thickness

35
Q

What does the synovial membrane line?

A

All the non-articular surfaces inside the joint cavity, up to the edge of the articular cartilage

36
Q

What histological layers can the synovial membrane be divided into?

A

The intima and the subintima

37
Q

What is the synovial intima like physically?

A

Thin and normally only 1-3 cells thick

38
Q

What are the cells in the synovial intima loosely called?

A

Synoviocytes

39
Q

What do synoviocytes do?

A

Secrete some of the components found in synovial fluid

40
Q

What is the subintima like?

A

Highly vascular and contains macrophages, fat cells and fibroblasts, which help maintain and protect the articular capsule during normal movement

41
Q

What is the joint cavity?

A

A small area between the articulating surfaces

42
Q

What are the peripheral margins of the joint cavity filled by?

A

The collapsing an in-folding of the synovial membrane (villi)

43
Q

What is the “potential space” (joint cavity) filled with?

A

Synovial fluid

44
Q

What does the amount of synovial fluid inside a healthy joint cavity really exceed?

A

1ml, even in large human joints like the knee

45
Q

What is synovial fluid?

A

A clear or slightly yellowish fluid that is an ultrafiltrate of blood plasma that leaks out of the vessels in the synovial membrane (subintima)

46
Q

What are the other components, besides blood filtrate, in synovial fluid secreted by?

A

Synoviocytes

47
Q

What are other components of synovial fluid?

A

Hyaluronic acid, free cells in low concentration (such as monocytes, lymphocytes, macrophages and synoviocytes)

48
Q

What is the function of synovial fluid?

A

Joint lubrication, shock absorption, chondrocyte metabolism and overall joint maintenance